CCEA GCE Specimen Assessment Material for Digital Technology

For first teaching from September 2016For first award of AS level in Summer 2017For first award of A level in Summer 2018Subject Code: 2650

CCEA GCE SpecimenAssessment Material for

Digital Technology

GCE

Version 2: Updated 6 March 2017

Version 2: 6 March 2017

ForewordCCEA has developed new specifications which comply with criteria for GCE qualifications. The specimen assessment materials accompanying new specifications are provided to give centres guidance on the structure and character of the planned assessments in advance of the first assessment. It is intended that the specimen assessment materials contained in this booklet will help teachers and students to understand, as fully as possible, the markers’ expectations of candidates’ responses to the types of tasks and questions set at GCE level. These specimen assessment materials should be used in conjunction with CCEA’s GCE Digital Technology specification.



GCE Digital TechnologySpecimen Assessment Materials

Contents

Specimen Papers 3

Assessment Unit AS 1: Approaches to System Development 3Assessment Unit AS 2: Fundamentals of Digital Technology 21Assessment Unit A2 1: Information Systems 39

Internal Assessment 61

Assessment Unit A2 2: Application Development (Case Study) 63

Mark Schemes 67

General Marking Instructions 69Assessment Unit AS 1: Approaches to System Development 73Assessment Unit AS 2: Fundamentals of Digital Technology 83Assessment Unit A2 1: Information Systems 91


Subject Code 2650

QAN ASQAN A2

601/8489/9601/8488/7

A CCEA Publication © 2016

You may download further copies of this publication from www.ccea.org.uk Version 2: 6 March 2017

SPECIMEN PAPERS

DIVIDER FRONT


SPECIMEN PAPERS

DIVIDER BACK


Centre Number

Candidate NumberADVANCED SUBSIDIARY (AS)

General Certificate of Education2017

For Examiner’s use only

Question Number

Marks

1

2

3

4

5

TotalMarks

TIME1 hour 30 minutes.

INSTRUCTIONS TO CANDIDATESWrite your Centre Number and Candidate Number in the spaces provided at the top of this page.Write your answers in the spaces provided in this question paper.Answer all five questions.

INFORMATION FOR CANDIDATESThe total mark for this paper is 100.Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question.Quality of written communication will be assessed in questions 2(e), 4(d) and 5(d).

3

Digital Technology

[CODE]SPECIMEN PAPER

Assessment Unit AS 1assessing

Approaches to System Development


Examiner Only

Marks Re-mark

4

1 The ‘software crisis’ has changed the way in which large information systems are developed.

(a) Explain the main impact of the ‘software crisis’.

[4]

(b) Identify two specific duties of the project manager during system development.

1

2

[2]


Examiner Only

Marks Re-mark

5

Fact-finding can be used to identify the user requirements during the analysis stage.

(c) Describe how document sampling can be used during fact finding.

[3]

(d) Using examples from a stock control system, illustrate the difference between functional and non-functional user requirements.

[4]


Examiner Only

Marks Re-mark

6

Customers of a bookshop can order a book by telephone or email. The book is posted to the customer. At the end of the month, the

customer receives an invoice. Customers can make payments by telephone or post, after which they receive a receipt by post.

(e) Produce a context data flow diagram for this book ordering system.

[6]


Examiner Only

Marks Re-mark

7

2 During the design stage of system development the test plan is produced.

(a) Identify three other activities you would expect to take place during system design.

1

2

3

[3]

(b) Describe how storyboarding can be used during the development of a web-based application.

[4]

(c) Identify two main components of a test plan.

1

2

[2]


Examiner Only

Marks Re-mark

8

During the implementation stage the new system replaces the existing system.

(d) Explain what happens during data conversion.

[3]


Examiner Only

Marks Re-mark

9

An organisation decides to use direct changeover for its new payroll system.

(e) Evaluate the organisation’s choice of changeover method.

Quality of written communication will be assessed in this question

[9]


Examiner Only

Marks Re-mark

10

3 An information system is being developed using the waterfall model.

(a) Describe the main features of the waterfall model.

[4]

The project manager identifies the project’s constraints and risks.

(b) Identify two risks to a typical software project and explain how each risk could affect the project.

1

2

[4]


Examiner Only

Marks Re-mark

11

The project manager uses Gantt charts and critical path analysis (CPA).

(c) Identify the main features of a Gantt chart.

[4]

(d) Describe the use of CPA in project management.

[4]


Examiner Only

Marks Re-mark

12

(e) Examine the following node from a CPA diagram:

Complete the following table:

Label Description2 The node number410D3

[4]

►

4D

310

2


Examiner Only

Marks Re-mark

13

4 After the implementation stage is complete, information systems still require maintenance.

(a) Describe what is meant by corrective maintenance.

[2]

(b) Explain why maintenance is required even when a system has been fully tested during development.

[6]


Examiner Only

Marks Re-mark

14

(c) Describe the contents of a disaster recovery plan.

[4]


Examiner Only

Marks Re-mark

15

A particular organisation decides to use a combination of full backups and differential backups.

(d) Evaluate the organisation’s decision.


[9]


Examiner Only

Marks Re-mark

16

5 A programmer uses an Integrated Development Environment (IDE) during the development of new software.

(a) List two facilities provided by an IDE.

1

2

[2]

The programmer uses iteration to solve a problem.

(b) Explain how iteration can be used to perform a particular calculation one hundred times.

[4]


Examiner Only

Marks Re-mark

17

Modern programming languages support object-orientated programming.

(c) What is meant by each of the following terms?

Object

Inheritance

[4]


Examiner Only

Marks Re-mark

18

(d) Evaluate the use of the object-oriented approach in improving the quality of the software produced.


[9]


THIS IS THE END OF THE QUESTION PAPER

19 Version 2: 6 March 2017

BLANK PAGE


Centre Number

Candidate NumberADVANCED SUBSIDIARY (AS)



Question Number

Marks

1

2

3

4

5

TotalMarks

TIME1 hour 30 minutes.

INSTRUCTIONS TO CANDIDATESWrite your Centre Number and Candidate Number in the spaces provided at the top of this page.Write your answers in the spaces provided in this question paper.Answer all five questions.You are not permitted to use any calculating aid in this paper.

INFORMATION FOR CANDIDATESThe total mark for this paper is 100.Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question of part question.Quality of written communication will be assessed in questions 3(e) and 5(d).

Digital Technology



Fundamentals of Digital Technology


Examiner Only

Marks Re-mark

22

1 (a) What is meant by each of the following terms?

A kilobyte

[1]

A megabyte

[1]

In the two’s complement system, positive and negative numbers can be represented in binary.

(b) Using the two’s complement system, convert each of the following binary values to decimal, showing all your work.

000011112

[2]

111101102

[2]


Examiner Only

Marks Re-mark

23

(c) Show how the decimal number − 44 can be represented as a two’s complement binary number using 8 bits.

[4]

ASCII and Unicode are both used to represent characters.

(d) Describe how the bits in a byte are used in ASCII.

[5]


Examiner Only

Marks Re-mark

24

(e) Discuss how Unicode differs from ASCII.

[3]


Examiner Only

Marks Re-mark

25

2 Consider the following extract from a table in a stock control application.

ProductID CurrentLevel ReorderLevel45667 343 400

(a) With the aid of examples, explain each of the following terms:

Data

[2]

Information

[2]

Knowledge

[2]

(b) Identify two factors which can affect the quality of information.

1

2

[2]


Examiner Only

Marks Re-mark

26

In the ProductID 45667, the 7 is a modulus 11 check digit.

(c) Show how this check digit is calculated.

[6]


Examiner Only

Marks Re-mark

27

(d) When completing an online application form, users must input their date of birth.

Discuss why both data validation and data verification should be performed in this case.

[6]


Examiner Only

Marks Re-mark

28

3 (a) The internal components of a computer include a clock. Describe the purpose of the clock.

[3]

(b) Explain what happens during the fetch-execute cycle.

[3]

(c) Describe the main features of a WIMP user interface.

[4]


Examiner Only

Marks Re-mark

29

(d) Describe how a touch screen can be used to input text into a smart phone.

[4]


Examiner Only

Marks Re-mark

30

A photograph can be stored as a bitmap, JPEG or GIFF.

(e) Evaluate all three of these formats for a photograph to be placed on a webpage.


[9]


Examiner Only

Marks Re-mark

31

4 The operating system manages all the operations of a computer.

(a) Identify three different tasks performed by a single user operating system.

1

2

3

[3]

Computer software includes utility programs.

(b) Describe the purpose of each of the following utilities.

Data compression software

[2]

Disk defragmenter software

[2]


Examiner Only

Marks Re-mark

32

Computer software also includes application software.

(c) Describe each of the following types of software.

Generic software

[2]

Special purpose software

[2]

Banks use both batch processing and real-time processing.

(d) Describe how batch processing is used to produce monthly bank statements.

[3]


Examiner Only

Marks Re-mark

33

(e) Justify the use of real-time processing for customer transactions at Automated Teller Machines (ATMs).

[4]


Examiner Only

Marks Re-mark

34

5 (a) Explain each of the following web technology terms:

The WWW

[2]

The Internet

[2]

URL

[2]

(b) Explain how an intranet differs from the Internet.

[2]


Examiner Only

Marks Re-mark

35

(c) A page on a travel agent’s web page contains the following text.

Produce the HTML code that will display this section of the web page.

[4]

Holiday types:

• Flights only• Flights and hotel• Cruises

Click here to continue to CCEAtravel.com


Examiner Only

Marks Re-mark

36

(d) When paying for goods online, the user enters their personal and payment details and then clicks the Proceed icon. A short while later their screen shows the message ‘Thank you for your order’.

By referring to this example, distinguish between client-side and server-side processing.


[9]




BLANK PAGE


Centre Number

Candidate NumberADVANCED


TIME2 hours 30 minutes.

INSTRUCTIONS TO CANDIDATESWrite your Centre Number and Candidate Number in the spaces provided at the top of this page.Write your answers in the spaces provided in this question paper.Answer all seven questions.

INFORMATION FOR CANDIDATESThe total mark for this paper is 150.Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question.Quality of written communication will be assessed in questions 3(c), 5(c), 6(b) and 6(c).

Digital Technology


Assessment Unit A2 1assessing

Information Systems

39


Question Number

Marks

1

2

3

4

5

6

7

TotalMarks


Examiner Only

Marks Re-mark

40

1 (a) Describe the purpose of each of the following network resources:

Server

[2]

Wireless access point

[2]

MAC address

[2]


Examiner Only

Marks Re-mark

41

(b) Compare and contrast a peer to peer network with a server based network.

[4]

Ring and star are two types of network topology.

(c) Describe the main features of a ring network.

[3]


Examiner Only

Marks Re-mark

42

(d) Compare the ring topology with the star topology with respect to each of the following:

Security

[3]

Reliability

[3]

(e) The OSI network model consists of a number of layers.

Describe the main features of the physical layer.

[3]


Examiner Only

Marks Re-mark

43

(f) Compare metal cable and fibre optic cable with respect to each of the following:

Bandwidth

[3]

Security

[3]


Examiner Only

Marks Re-mark

44

2 A library stores details of its members, books, and loans in a relational database.

(a) Describe the main features of a relational database.

[4]

The database includes the following tables:• Book (BookID, Title, Author, Publisher, Category)

• Member (MemberID, Surname, Forename, HouseNumber, Postcode, EmailAddress)

• Loan (MemberID, BookID, DateOfLoan, DateDueBack, Returned)

(b) Using examples from this database, explain each of the following terms:

Entity

[2]

Attribute

[2]


Examiner Only

Marks Re-mark

45

Primary key

[2]

Composite key

[2]


Examiner Only

Marks Re-mark

46

(c) Show how the Book, Member and Loan tables could be represented in an Entity Relationship (ER) Diagram.

[4]

(d) Data in the library’s database has been normalised.

Describe two advantages of data which is normalised.

1

[2]

2

[2]


Examiner Only

Marks Re-mark

47

Structured Query Language (SQL) is used to• maintain data in the database• create queries

(e) Using SQL produce a command which will add details of the following loan to the database.

MemberID: 43216BookID: 21345DateOfLoan: 24/08/2016DateDueBack: 31/08/2016Returned: False

[3]

(f) Using SQL produce a query which will retrieve the Title and Author of all Science books in the database.

[3]


Examiner Only

Marks Re-mark

48

(g) The librarian is not a Digital Technology expert.

Explain why the librarian might use Query by Example (QBE) to create a query.

[4]


Examiner Only

Marks Re-mark

49

3 Digital Technology plays a key role in mobile phone communication.

(a) Describe the technology which enables a mobile phone user to make phone calls while on the move.

[6]


Examiner Only

Marks Re-mark

50

A hospital uses an expert system to help diagnose patients’ illnesses before they are seen by a consultant.

(b) Explain the meaning of each of the following terms:

Expert system shell

[3]

Fuzzy logic

[3]

Heuristics

[3]


Examiner Only

Marks Re-mark

51

(c) Evaluate the hospital’s use of an expert system.


[9]


Examiner Only

Marks Re-mark

52

4 Data mining is used by many businesses to increase their competitiveness.

(a) What is meant by data mining?

[4]

(b) Explain how a chain of supermarkets could use data mining to increase its competitiveness.

[7] Version 2: 6 March 2017

Examiner Only

Marks Re-mark

53

5 When using Personal Data most organisations must comply with the Data Protection Act.

(a) Identify four principles specified in the Data Protection Act.

1

2

3

4

[4]

(b) Describe two rights the DPA gives the data subject.

1

[2]

2

[2]


Examiner Only

Marks Re-mark

54

(c) Discuss the main ethical considerations relating to the use of personal information by companies.


[9]


Examiner Only

Marks Re-mark

55

6 Many organisations make use of virtualisation and cloud computing.

(a) Describe how virtualisation can be used on a computer system.

[6]


Examiner Only

Marks Re-mark

56

A large organisation decides to upgrade its payroll system. The organisation decides to use a third party to host the new payroll

system.

(b) Evaluate the organisation’s decision to use a third party with respect to security.


[9]


Examiner Only

Marks Re-mark

57

(c) Explain the impact of the increasing use of cloud computing on the memory requirements of personal computers.


[9]


Examiner Only

Marks Re-mark

58

7 When data is sent over a network it is important that data transmission errors are detected.

(a) Describe how each of the following can be used to detect data transmission errors:

Parity bits

[4]

CRC

[4]


Examiner Only

Marks Re-mark

59

When sensitive data is sent over the Internet it is important that it is kept secure.

(b) Explain how each of the following can be used to keep data secure:

SSL

[4]

Digital Certificate

[4]




61

INTERNAL ASSESSMENT

DIVIDER FRONT


62

INTERNAL ASSESSMENT

DIVIDER BACK


ADVANCEDGeneral Certificate of Education

2018

INTERNAL ASSESSMENT

Digital Technology

[CODE]SPECIMEN

Case StudyAssessment Unit A2 2

assessingApplication Development


64

A2 2: Application Development (Case Study)

Information for Candidates

This unit is internally assesssed.

In this unit, you will have the opportunity to become involved in a real-world situation detailed in a case study. You will apply your skills, knowledge and understanding of digital technology to solve a problem for a specified client.

You will apply your practical skills to produce a solution and associated detailed documentation for the client. You can adopt a range of approaches, but your teacher will guide you in selecting an approach suitable to your particular knowledge and skills.

The case study will give you an opportunity to demonstrate your skills in:• analysing the problem;• designing an appropriate solution to the real-world problem;• developing the solution;• testing the solution;• evaluating the solution; and• developing user support documentation.


65

Case Study:

Bobby Walsh owns a company called the Rathlin Boating Company. It is based in the town of Ballycastle on the north coast of Northern Ireland and specialises in the provision of a range of trips and excursions along the County Antrim coast. It caters for individuals and groups, up to a maximum of 20 people. Bobby currently has 4 members of staff, each of whom captains a boat.

Currently all bookings are made via telephone or email and are directly managed by Bobby. When a request comes through, Bobby consults the diary to see what’s available. However, at times he has taken bookings without consulting the diary, or forgotten to make an entry.

To help manage his bookings more effectively, Bobby has approached you, as a Digital Technology specialist, to produce an appropriate business solution for him. You will have to carry out an in-depth analysis to identify Bobby’s requirements, design an appropriate solution, implement the solution and produce associated documentation.

Overall Marks allocated for this unit = 120.


BLANK PAGE


MARK SCHEME

DIVIDER FRONT


MARK SCHEME

DIVIDER BACK


General Certificate of Education

GENERAL MARKING INSTRUCTIONS

Digital Technology


70

General Marking Instructions

IntroductionThe main purpose of the mark scheme is to ensure that examinations are marked accurately, consistently and fairly. The mark scheme provides examiners with an indication of the nature and range of candidates’ responses likely to be worthy of credit. It also sets out the criteria which they should apply in allocating marks to candidates’ responses.

Assessment objectivesBelow are the assessment objectives for GCE Digital Technology.

Candidates should be able to:AO1 Demonstrate knowledge and understanding of the concepts, and the characteristics,

components and functions of digital technology systems.

AO2 Apply knowledge and understanding of Digital Technology to investigate and analyse problems and propose solutions.

AO3 Design, develop and evaluate Digital Technology solutions to solve problems, making reasoned judgments and presenting conclusions.

Quality of candidates’ responsesIn marking the examination papers, examiners should be looking for a quality of response reflecting the level of maturity which may reasonably be expected of a 17 or 18-year-old which is the age at which the majority of candidates sit their GCE examinations.

Flexibility in markingMark schemes are not intended to be totally prescriptive. No mark scheme can cover all the responses which candidates may produce. In the event of unanticipated answers, examiners are expected to use their professional judgement to assess the validity of answers. If an answer is particularly problematic, then examiners should seek the guidance of the Supervising Examiner.

Positive markingExaminers are encouraged to be positive in their marking, giving appropriate credit for what candidates know, understand and can do rather than penalising candidates for errors or omissions. Examiners should make use of the whole of the available mark range for any particular question and be prepared to award full marks for a response which is as good as might reasonably be expected of a 17 or 18-year-old GCE candidate.

Awarding zero marksMarks should only be awarded for valid responses and no marks should be awarded for an answer which is completely incorrect or inappropriate.

Marking Calculations In marking answers involving calculations, examiners should apply the ‘own figure rule’ so that candidates are not penalised more than once for a computational error. To avoid a candidate being penalised, marks can be awarded where correct conclusions or inferences are made from their incorrect calculations.


71

Types of mark schemesMark schemes for tasks or questions which require candidates to respond in extended written form are marked on the basis of levels of response which take account of the quality of written communication.

Other questions which require only short answers are marked on a point for point basis with marks awarded for each valid piece of information provided.

Levels of responseIn deciding which level of response to award, examiners should look for the ‘best fit’ bearing in mind that weakness in one area may be compensated for by strength in another. In deciding which mark within a particular level to award to any response, examiners are expected to use their professional judgement.

The following guidance is provided to assist examiners.

• Threshold performance: Response which just merits inclusion in the level and should be awarded a mark at or near the bottom of the range.

• Intermediate performance: Response which clearly merits inclusion in the level and should be awarded a mark at or near the middle of the range.

• High performance: Response which fully satisfies the level description and should be awarded a mark at or near the top of the range.

Quality of written communicationQuality of written communication is taken into account in assessing candidates’ responses to all tasks and questions that require them to respond in extended written form. These tasks and questions are marked on the basis of levels of response. The description for each level of response includes reference to the quality of written communication.

For conciseness, quality of written communication is distinguished within levels of response as follows:Level 1: Quality of written communication is basic.Level 2: Quality of written communication is good.Level 3: Quality of written communication is excellent.

In interpreting these level descriptions, examiners should refer to the more detailed guidance provided below:

Level 1 (Basic): The candidate makes only a limited selection and use of an appropriate form and style of writing. The organisation of material may lack clarity and coherence. There is little use of specialist vocabulary. Presentation, spelling, punctuation and grammar may be such that intended meaning is not clear.

Level 2 (Good): The candidate makes a reasonable selection and use of an appropriate form and style of writing. Relevant material is organised with some clarity and coherence. There is some use of appropriate specialist vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make meaning clear.

Level 3 (Excellent): The candidate successfully selects and uses the most appropriate form and style of writing. Relevant material is organised with a high degree of clarity and coherence. There is widespread and accurate use of appropriate specialist vocabulary. Presentation, spelling, punctuation and grammar are of a sufficiently high standard to make meaning clear.


72

BLANK PAGE


MARK SCHEME

Digital Technology

[CODE]SPECIMEN

ADVANCED SUBSIDIARY (AS)General Certificate of Education

2017


Approaches to System Development


AVAILABLE MARKS

74

1 (a) It was recognised that the way in which software is developed must be radically changed [1], because users’ needs were not being met/ users’ needs were being met [1]. This is to ensure software meets the user requirements [1]. Software is developed on time/not on time [1] and within budget/outside budget [1]. Quality process not being followed [1]. Effective advances in hardware and software were not being used in the production of software e.g. IDE [1]

Any four points [4]

(b) Plan the project’s schedule [1] Split the project up into tasks/subtasks [1] Allocate resources such as personnel, Digital Technology to each

task/subtask [1] Identify risks to the project [1] Monitor the progress of the project [1]

Any two specific duties [2]

(c) This is used to find out how data flows through the organisation [1]. It looks at how data is input [1], collated [1], processed [1] and reported [1]. Typical documents are data collection forms, invoices, orders, receipts [1]

Any three points [3]

(d) Functional requirements specify what a software system must do. [1]

Example: when the shock level for a product falls below it’s re-order level, a re-order request should automatically be generated. [1]

Non-functional requirements specify additional criteria by which the system will be judged. [1]

Example: the sale of an item at a POS terminal should be recorded in the database within x seconds. [1] [4]

(e)

[1] for ‘Process orders’ (or similar) [1] for identifying Level 0 [1] for Customer as data source/destination [1] for two data flows in [1] for three data flows out [1] for correct symbols [6]

CustomerOrder

►

Payment►

Process orders

Book

Invoice

Receipt►

►

►

Customer0

19


AVAILABLE MARKS

75

2 (a) Specification of data structures [1] Design of user interfaces [1] Design of queries and reports [1] Identification of the data validation to be used [1] Identification of the data verification to be used [1]

Any three activities [3]

(b) Diagrams [1] will be produced for each page of the website [1]. Each diagram will show the user interface of the page [1]. This will include user input/output [1] and the different navigation paths available to the user [1]

Any four points [4]

(c) The item (e.g. module or text field) to be tested [1] The test data to be used [1] The expected outcome [1]

Any two points [2]

(d) Data is taken from existing system [1]. Data converted into a suitable format [1]

Non-electronic data may have to be converted to electronic form [1] File formats may need to be changed [1] Non-electronic data is taken from existing system [1] is converted to

electronic form [1]


(e) Indicative content Candidates may discuss the following:

The method The new system replaces the existing system in one go The old system is discarded This is usually done at a quiet processing period e.g. overnight

Advantage This method is very efficient because there is no duplication of Digital

Technology resources or personnel.

Disadvantage There is a potential high risk with this method – if the new system

fails in any way there is no backup system available

The context The risk should be low since payroll is a standard business process

and follows established steps which can be tested in advance, and payroll is an isolated function within a business and any risk will be confined to one business area.


AVAILABLE MARKS

76

Level of response Marking criteria Marks

Band 3:Excellent

The candidate accurately describes the changeover method. The candidate addresses both advantages and disadvantages of this approach and refers directly to the context of a new payroll system in a coherent manner. The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]–[9]

Band 2:Good

The candidate describes the changeover method, addressing some advantages and disadvantages of this approach but does not apply this directly to the context of a new payroll system. The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make the response clear.

[4]–[6]

Band 1:Basic

The candidate refers to the changeover method and identifies an advantage or disadvantage. The candidate makes no reference to the new payroll system. The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]–[3]

The response is not worthy of credit [0] 21


AVAILABLE MARKS

77

3 (a) Consists of a number of distinct stages e.g. analysis [1] stages are sequenced [1]

One stage must be completed before the next stage commences [1] There is a deliverable at the end of each stage e.g. system

specification [1] If an error is found at any stage, an earlier stage may have to be

revisited [1]

Any four points [4]

(b) A task/subtask might take too long [1]. This could mean that tasks/subtasks depending on its completion may not be able to start as scheduled [1]. Task may exceed its budget [1]. This would lead to software not being developed until financial constraints are resolved [1]

A key member of the team might be unavailable when required [1] This could mean that a task/subtask may not be able to start [1]

Any four points [4]

(c) A Gantt chart is similar to a bar chart [1]. It identifies each project activity [1] and its planned start time [1] and finishing time [1]. It shows the current progress of the project with a vertical bar [1]

Any four points [4]

(d) A model of the project is constructed showing each activity as a node [1], and the dependencies between the activities [1]

A mathematical algorithm is used to calculate the earliest and latest starting and finishing time for each activity [1]

The algorithm identifies the chain of activities critical to the project’s schedule [1]

CPA identifies the most efficient way of ensuring the project’s schedule is met with optimal use of resources [1]

Use of CPA requires the use of special software and expertise on the part of the project manager and may be unsuitable for small scale projects [1]

Any four points [4]

(e)

Label Description2 The node number

4 Earliest start day [1]

10 Latest finish day [1]

D The name of the activity [1]

3 The duration of the activity [1] [4]

20


AVAILABLE MARKS

78

4 (a) Errors may not be identified until the system has been in use [1] These errors must be debugged and the system retested [1] [2]

(b) The user requirements may change after the system has been in use for some time [1]. This may be because of internal changes [1] or because of external changes [1]. In this case, adaptive maintenance is required [1]

Any three points

The system may still meet the user requirements [1] but the performance of the system may require improving [1]. This could be to take advantage of new hardware and software to improve processing speeds [1]. In this case, perfective maintenance is required [1]


(c) It will describe how the organisation will continue to function after a natural disaster [1]. It will identify the main risks to the organisation

from possible disasters [1]. It will identify critical data [1]. It will identify recovery method to be used [1]. It will identify critical data processing operations [1]. It will dentify key personnel [1]. It will ensure personnel continue to have access to the organisation’s computer systems [1]. It will specify the procedures to be performed if a disaster occurs [1]. It may identify an alternative location where the organisation could operate until the threat/damage is over [1]

Any four points [4] (d) Indicative content Candidates may discuss the following:

Differential backup Data files which have changed …since the last full backup are copied. The regular backup procedure consists of a differential backup. Full backups are done less frequently.

Advantage This is an efficient process as differential backup do not take as long.

The amount of disk space used by differential images is significantly less than that of a full image. Only two image files are required to restore the system.

Disadvantage If the system fails and data has to be recovered …the recovery process is more complicated. The last full backup has to be restored first …followed by all subsequent differential backups. The longer the time betweem the full and the differential, the larger

the differential image file will be and the longer it will take to create.


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Band 3:Excellent

The candidate accurately describes how differential backups are used in this combination of backup methods, clearly articulating both the advantages and disadvantages of this method. The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]–[9]

Band 2:Good

The candidate describes this combination of backup methods, and sets out either the advantages or disadvantages of this method. The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make the response clear.

[4]–[6]

Band 1:Basic

The candidate demonstrates an awareness of a differential backup, and refers to an advantage or disadvantage of this method. The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]–[3]



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5 (a) A smart programmer editor [1] Run/debug options [1] Automatic production of documentation [1] Project management features [1]

Any two points [2]

(b) A sequence of instructions/code [1] ...is repeated a number of times [1] A variable will be used to control a loop [1] This variable will be initialised [1] ...and incremented each time the loop is executed [1] The loop will be performed until the value of the variable reaches 100

[1]

Any four points [4]

(c) Object A self-contained component that incorporates data/properties [1] and

functions/methods [1]

Inheritance The mechanism whereby the properties and methods of one class [1]

can be automatically copied to another class [1] [4]

(d) Indicative content Candidates may discuss the following:

The approach Advantages More accurate modelling – the object oriented approach models the

real world more realistically than traditional methods which focus on data and processing.

Improved productivity due to code reusability – when a new object is created, it will automatically inherit the data attributes and characteristics of any class from which it is derived.

The primary goal of object-orientated development is the assurance that the system will enjoy a longer life while having far smaller maintenence costs. Because most of the processes within the system are encapsulated, the behaviours may be reused and incorporated into new behaviours.


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Disadvantages The object oriented approach is not suited for all applications. It has been widely adopted in CAD/CAM and engineering design

systems but it has not been as successful for either corporate systems or many ‘run of the mill’ information systems applications such as payroll and accounting.

Object-orientated Development is not yet completely accepted by major vendors. While there is a general acceptance of object-orientated systems in the commercial marketplace, organisations do not have the time to train their staffs in object-orientated metheods.


Band 3:Excellent

The candidate accurately describes how the use of the OO approach can improve software quality. The candidate clearly articulates both the advantages and disadvantages of this approach. The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]–[9]

Band 2:Good

The candidate describes the OO approach but doesn’t refer to software quality. The candidate describes the advantages or disadvantages of this approach. The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make the response clear.

[4]–[6]

Band 1:Basic

The candidate makes some reference to the OO and doesn’t refer to software quality. The candidate refers to an advantage or disadvantage of this approach. The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]–[3]

The response is not worthy of credit [0]

Total

19

100


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MARK SCHEME

Digital Technology

[CODE]SPECIMEN

ADVANCED SUBSIDIARY (AS)General Certificate of Education

2017


Fundamentals of Digital Technology


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1 (a) kilobyte 210 or 1024 bytes [1]

Megabyte 220 or 1,048,576 bytes [1] [2]

(b) 000011112 1 + 2 + 4 + 8 = 1510 [1] + [1]

111101102 Invert 000010012 [1] Add 1 000010102 = - (2 + 8) = -1010 [1] [4]

(c) 4410 [1] 001011002 [1] Invert 110100112 [1] Add 1 110101002 [1] [4]


7 bits are used for characters [1] This gives a range of 128 characters [1] …which includes 96 displayable characters [1] …and 32 control codes [1];

A character is a letter or digit or special character [1] The 8th bit can be used as a parity bit [1] …for error checking [1] 8 bits can give a range of 256 [1];

Displayable characters; control codes [1]

Any five points [5]

(e) Unicode uses 16 bits [1] This provides a much greater range [1] This increases by a factor of 28 the number of different characters

which can be represented [1] This is used to represent characters from most of the world’s

languages [1]


2 (a) Data Data is unprocessed [1] Example 45667 [1] [2]

Information Processed data [1] Example 45667 is a ProductID [1] [2]

Knowledge The application of information [1]

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Example Product 45667 needs re-ordering [1] [2]

(b) Accuracy [1] Relevance [1] Up to date/currency [1] Completeness [1] Presentation [1] Reliability [1]

Any two points [2]

(c) 4 5 6 6

Weighting 5 4 3 2 [1]

Product 20 20 18 12 [1]

Sum 70 [1]

Remainder 70 ÷ 11 = 6 R 4 [1] + [1]

Checkdigit 11−4=7 [1] [6]


Data validation will check that the date is a valid date [1]; range check will be used [1]

Example: the month number lies in the range 1 to 12 inclusive [1] However, this does not check that the date is the one the user

intended to enter [1]

Data verification confirms that the date entered was the intended date [1] Example: day/month/year with reference to upper boundary [1] day/month/year with reference to lower boundary [1] Proof reading will be intended method [1] The user will compare data entered with original [1]

Any six points [6]

3 (a) Synchronises all internal processes/components [1] by generating pulses [1] at a constant rate [1] [3]

(b) The control unit [1] gets each instruction in sequence [1] It decodes the instruction [1] and then carries it out by sending control

signals to other parts of the computer [1] [3]

Any three points

(c) Each task has its own window [1] Windows can be maximised and minimised [1] Icons represent programs/files/shortcuts [1]

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Icons can be double clicked to open [1] Menus contain lists of options [1] Menus can contain sub menus [1] A pointer is used to move a cursor [1] Rather than cursor key on a keyboard [1]

Any four points [4]

(d) A capacitive touch screen is used [1] This consists of a grid of tiny, transparent electrodes [1] The touch screen displays a keyboard [1] When the screen is touched with a finger or stylus, there is a change

in the electrostatic properties at that point [1] This enables the typed character to be determined [1]

Any four points [4]

(e) Indicative content Candidates may discuss the following:

A bitmap image retains all the image details …at the expense of a large file size. This can impact on the download time of the page. The resolution of a JPEG image can be reduced …using compression techniques. This also reduces file size but at the expense of image quality. GIF stands for Graphics Interchange Format and is one of the file

formats usd to display indexed-colour graphics and images in HTML documents on the web. This means that a GIF will only display a maximum of 256 colours; as a result, GIFS are great for images with simple illustrations and blocks of colours, like logosw and icons, but probably not the best option for photographs.


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87


Band 3:Excellent

The candidate accurately describes how an image can be stored using both of these methods. The candidate articulates clearly the advantages and disadvantages of each method referring directly to an image to be placed in a website. The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]–[9]

Band 2:Good

The candidate describes how an image can be stored usingbothofthesemethods.Thecandidateidentifiesan advantage or disadvantage of each method but does not refer to an image to be placed in a website. The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammararesufficientlycompetenttomaketheresponse clear.

[4]–[6]

Band 1:Basic

Thecandidateidentifiesonefeatureofeachtypeof image representation but does not refer to any advantage or disadvantage. The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]–[3]



AVAILABLE MARKS

88

4 (a) Memory management [1] Allocation of resources such as printers [1] Handling user input [1] Handling output [1]


(b) Data compression software Reduces the physical size of data [1] in order to save storage space [1] Reduce transmission time [1] Any two points [2]

Disk defragmenter software Decreases access times [1] uses storage more efficiently [1] by

merging fragmented files into one contiguous block or space [1]

Any two points [2]

(c) Generic software Performs general tasks and is not limited to one particular application [1] Software may not meet the exact user requirements [1] Example: a spreadsheet application [1]

Any two points [2]

Special purpose software Designed for a specific application [1] Software will meet the exact user requirements [1] Example: payroll software [1]

Any two points [2]

(d) Transactions are saved temporarily [1] ...until the end of the month [1] All transactions for the month are used [1] ...to produce monthly bank statements [1]


(e) In real-time processing, each transaction is processed immediately [1] Files are updated [1] before the next transaction takes place [1] This is needed for ATM transactions as withdrawals and deposits to

an account must be implemented immediately [1] ...so the account balance is always up to date [1] Personal Identification Number (P.I.N.) changes updated

immediately [1]

Any four points [4] 18


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5 (a) The WWW A system of interlinked hypertext documents [1] that are accessed via

the Internet using a browser [1] [2]

The Internet A global computer network [1] consisting of interconnected networks

using communication protocols [1] [2]

URL A unique address [1] identifying every resource on the Internet [1] [2]

(b) The Internet is a global network [1] An intranet is a private network[1]; restricted network [1]; Requires a

username and password [1]

Any two points [2]

(c) <p>Holiday types:</p> [1] <ul> [1] <li>Flights only</li> [1] <li>Flights and hotel</li> [1] <li>Cruises</li> [1] </ul> <a href=”http://www.cceatravel.com/”>Click here to continue to CCEA

Travel.com</a> [1]

Any four points [4]


The user’s browser performs any processing it can ... on the clients computer ... such as validate a debit/credit card number is numeric Check all compulsory fields have been completed e.g. Expiry date,

security number, name, credit card number. Check all fields have been completed with valid data such as

validating a debit/credit card number as numeric. When the user clicks Proceed, the link with the server is

re-established and the completed web page is sent to the server The server completes the processing ...for example by authorising the payment details with the users bank ... authorising credit card details with bank The server then sends the confirmation page back to the client

computer.

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Band 3:Excellent

The candidate accurately and coherently articulates the difference between client-side and server-side processing inthespecificcontextofthescenario.Thecandidateusesthe appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]–[9]

Band 2:Good

The candidate describes the main difference between client-side and server-side processing but does not refer clearly to the scenario. The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuationandgrammararesufficientlycompetenttomake the response clear.

[4]–[6]

Band 1:Basic

The candidate attempts to distinguish between client-side and server-side processing. The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]–[3]


Total 100


Digital Technology

[CODE]SPECIMEN

MARK SCHEME

ADVANCEDGeneral Certificate of Education

2018

Assessment Unit A2 1assessing

Information Systems


AVAILABLE MARKS

92

1 (a) Server Manages shared network resources [1] such as data/files/peripherals

[1]. It processes requests from other nodes [1]

Any two points [2]

Wireless access point To connect wireless devices [1] to a wired network [1] using Wi-Fi or

Bluetooth [1]

Any two points [2]

MAC address Assigns an unique address [1] to each node on the network [1] which

identifies the network interface card [1]

Any two points [2]

(b) In a peer to peer network, all nodes have equal status [1] Nodes share their resources with one another [1] In a server based network, one node controls the network and its

resources [1] Other nodes request resources from the server [1] Remote software upgrades are possible with client server [1] Peer to peer upgrades managed independently on each node [1]

Any four points [4]

(c) The nodes are connected in a loop [1] Each node may be connected directly to the ring or by a spur [1] Data passes from node to node [1] until it reaches its intended

recipient [1] Data travels in one direction [1]


(d) Security The star topology is more secure [1] because the server sends data

directly to its intended recipient [1]. In the ring topology, data is sent from node to node [1] until it reaches intended recipient [1]


Reliability The star topology is more reliable [1] because if a link fails, only one

node is affected [1]. In the ring topology, if a link fails the loop fails [1] If the central server fails in a Star network then whole network goes

down [1]



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93

(e) This operates at hardware level [1] It transmits and receives streams of bits [1] It specifies voltage levels [1], specifies timings [1]


(f) Bandwidth Fibre optic cable provides more bandwidth than metal cables [1]

because a single cable consists of multiple strands [1] each strand capable of carrying multiple data signals [1]. A metal cable only has a capacity equal to one of these strands [1]


Security Fibre optic cable is more secure [1] as it is difficult to intercept its

signal without destroying it [1]. The signal in a metal cable can be detected electromagnetically [1]. Physical casing is more secure [1].Metal cable is more susceptible to interference due to copper medium [1]; where as fibre optic uses light medium [1]


2 (a) Data is stored in tables [1] consisting of records [1] Each record is uniquely identified by a primary key [1] Tables are linked via primary keys [1] and foreign keys [1]

Any four points [4]

(b) Entity An object/subject about which information is stored [1] such as

Member/Book/Loan [1] [2]

Attribute Each data item within an entity [1] such as Title in Book [1] [2]

Primary key An attribute which uniquely identifies an entity occurrence/record [1]

such as BookID [1] [2]

Composite key A composite key consists of two or more key fields each of which may

be a primary key in another table/which together uniquely identify an entity occurrence [1] such as MemberID+BookID [1] [2]

(c)

[1] + [1] for two correct relationships [1] for all three entities [1] for proper ERD symbols [4]

28

LOAN MEMBERBOOK


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94

(d) Data redundancy is minimised [1] which minimises storage requirements [1] [2]

Data inconsistency is minimised [1] which improves data integrity [1] [2] (e) INSERT INTO Loan [1] VALUES ( 43216,21345, 24/08/2016, 31/08/2016, False ) [1] + [1] [3]

(f) SELECT Title, Author [1] FROM Book [1] WHERE Category = “Science” [1] [3]

(g) Using QBE, the librarian can enter the search criteria [1] by selecting an option from a list [1] or by entering values in text boxes [1]. This requires less expertise than using SQL whose commands have a complicated syntax [1] [4]

3 (a) The mobile phone uses a special radio frequency [1] to contact the nearest mobile phone mast [1]

A separate radio frequency is used to transmit the phone conversion [1]

Each phone mast controls a cell [1] Adjacent cells overlap to ensure maximum coverage [1] If there is more than one phone mast in range, the mast receiving the

strongest signal from the mobile phone is used [1] As the phone user moves out of the mast’s range, a nearby mast will

take control of the call [1] A local base station controls a number of phone masts [1] The local base station routes the phone call to its mobile switching

centre [1]

Any six points [6]

(b) Expert system shell This assists/automates the creation of the expert system [1] It is an empty or skeletal expert system [1] For a particular application, the relevant rules and facts are added [1] [3] Fuzzy logic Deal with uncertainties [1] Statements are assigned probabilities [1] rather than being either true or false [1] [3]

Heuristics These are rules [1] derived from human experience [1] or intuition [1] [3] (c) Indicative content Candidates may discuss the following:

The expert system’s knowledge base contains information and rules about illnesses and symptoms.

The patient responds to questions and the expert system provides a diagnosis of the patient’s illness.

30


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Advantages The expert system’s knowledge can reflect the knowledge of a large

number of medical experts The expert system will produce accurate and consistent diagnoses Make rational decisions without any emotional overhead Knowledge of expert staff can be captured to some extent before they

move on to new locations or jobs Can be used as a training aid to increase the expertise of staff Efficient way of providing answers to queries (reducing wait times) as

it does not involve additional help to staff Natural language interface would make the expert system more

human friendly

Disadvantages The expert system cannot use intuition Overreliance on expert systems could lead to a loss of human

expertise/skills A lot of effort and cost has to go into making a good expert system Not as good as having human experts to hand Most expert systems are menu driven which does not deal very well

with ambiguous problems Does not learn from mistakes unless user feedback and human

maintenance is part of its ongoing development


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96

Level of Response Marking Critera Marks

Band 3:Excellent

The candidate describes accurately and coherently how the expert system is used in the hospital. The candidate articulates clearly the main advantages and disadvantages of using an expert system in this context.The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]−[9]

Band 2:Good

The candidate describes broadly how the expert system is used in the hospital. The candidate identifies some advantages or disadvantages of using an expert system but may not refer to the hospital.The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make the response clear.

[4]−[6]

Band1:Basic

The candidates attempts to explain how the expert system might be used in the hospital. The candidate identifies an advantage or disadvantage of using an expert system but does not refer to the hospital.The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]−[3]


24


AVAILABLE MARKS

97

4 (a) Data mining involves the automatic analysis [1] sorting of large data sets in a data warehouse [1]. Information is combined from a number of sources [1]. The aim is to identify trends [1] and correlations [1]

Any four points [4]

(b) Supermarkets mine point-of-sale data [1] and data collected from loyalty cards [1] to create accurate customer profiles [1] and to improve their targeting of products and services [1]

They can identify the products whose sales are most susceptible to promotional events [1]

They can get a clear picture of demand for product ranges and ensure stores are appropriately stocked [1]

They also mine socio-economic data [1] and data about competitors [1] to help them devise marketing strategies [1]

Any seven points [7]

5 (a) Personal data must be:

1 Processed fairly and lawfully. 2 Obtained for specified and lawful purposes. 3 Adequate, relevant and not excessive. 4 Accurate and up to date. 5 Not kept any longer than necessary. 6 Processed in accordance with the “data subject’s” (the individual’s) rights. 7 Securely kept. 8 Not transferred to any other country without adequate protection

in situ.

Any four principles [4]

(b) Right of access [1] The data subject has a right to be supplied with the personal data

held about them [1]

Right of correction [1] The data subject may force a data controller to correct any mistakes

in the data held about them [1]

Right to prevent distress [1] The data subject may prevent the use of information if it would be

likely to cause them distress [1]

Right to prevent direct marketing [1] The data subject may stop their data being used for junk mail or cold

calling [1]

Right to prevent automatic decisions [1] The data subject may specify that they do not want a data user to

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make automated decisions about them Example: where, through points scoring, a computer decides on a loan application [1]

Right of complaint [1] The data subject can ask for the use of their personal data to be

reviewed by the Information Commissioner who can enforce a ruling [1]

[2] for each of any two rights [4]

(c) Indicative content Candidates may discuss the following:

In general, legislation lags behind developments in Digital Technology and ethics fill the gap. The increasing and expanding use of Digital Technology for gathering, storing, manipulating, and communicating data

…has revolutionised the use and spread of information and has created ethical dilemmas.

Personal data can be used for purposes quite different from its intended use

…because the legislation governing who can use the data and for what purpose may not be clear or restrictive enough

…to protect the intentions and interests of the subjects.

Companies may obtain data legitimately from a number of third-party sources but combine this data in ways of which the data subject has no understanding. Companies may obtain medical, financial and criminal records even though they have no relevance to their business.

Users of data must recognise changes in rights and responsibilities …and adapt their standards of conduct which date from before the

advent of computers.


AVAILABLE MARKS

99

Level of Response Marking Criteria Marks

Band 3:Excellent

The candidate articulates clearly a range of ethical considerations relating to the use of personal information with specific reference to the broader consequences for the companies using the data.The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]−[9]

Band 2:Good

The candidate describes some ethical considerations relating to the use of personal information by companies. The candidate makes some reference to the consequences for organisations.The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make the response clear.

[4]−[6]

Band 1:Basic

The candidate attempts to describe some issues but fails to distinguish between legal and ethical considerations.The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]−[3]


6 (a) Virtualisation The creation of a virtual version of a device or resource [1] where

users (devices, applications or human users) can interact with the virtual resource as if it were a real single resource [1]

Storage virtualisation [1] is the amalgamation of multiple network storage devices into a single storage unit [1]

Server virtualisation [1] is the partitioning of a physical server into smaller virtual servers [1]

Operating system virtualisation [1] where multiple operating systems can be used on a single server [1]

Network virtualisation [1] in which all servers and services in the network are treated as a single pool of resources that can be accessed without regard for its physical components [1]

Application virtualisation [1] where each application adapts its set of configurations on-demand [1]

Any six points [6]

17


AVAILABLE MARKS

100

(b) Indicative content Candidates may discuss the following:

The third party will provide the payroll system via a URL and it will maintain the organisation’s payroll database.

The organisation will use this URL to run its payroll instead of running the payroll system on its own network and maintaining the payroll database themselves.

The organisation does not need to implement its own security specifically for their payroll operations.

Security is implemented by the third party. This removes control over security from the organisation as they have

to rely on the third party’s security.


Band 3:Excellent

The candidate articulates clearly how the organisation will use a third party in this case. The candidate describes clearly and accurately the security considerations, including the key advantages and disadvantages.The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]−[9]

Band 2:Good

The candidate describes how the organisation will use a third party in this case. The candidate addresses the issue of security, and identifies some advantages or disadvantages.The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make the response clear.

[4]−[6]

Band 1:Basic

The candidate attempts to explain how the organisation will use a third party in this case. The candidate does not address the issue of security, but identifies an advantage or disadvantage.The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]−[3]



AVAILABLE MARKS

101

(c) Indicative content Candidates may discuss the following:

Instead of storing data on the personal computer’s external memory …such as the hard disk/DVD/flash memory …data is uploaded to the internet …where it is stored on a remote server ... unlimited storage capacity ...host is responsible for all updates ...host is reponsible for all backups This has reduced the need for high capacity external memory on

personal computers This has not reduced the need for internal memory Device independence Increased data reliability


AVAILABLE MARKS

102


Band 3:Excellent

The candidate articulates clearly how a personal computer user can make use of cloud computing. The candidate explains in detail the main consequences on the resource requirements of the personal computer.The candidate uses the appropriate Digital Technology vocabulary accurately. Presentation, spelling, punctuation and grammar are of a high standard.

[7]−[9]

Band 2:Good

The candidate describes how a personal computer user can make use of cloud computing. The candidate describes some consequences on the resource requirements of the personal computer.The candidate uses some relevant Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are sufficiently competent to make the response clear.

[4]−[6]

Band 1:Basic

The candidate refers to a personal computer user using cloud computing. The candidate makes some reference to the use of resources on the personal computer.The candidate makes limited use of Digital Technology vocabulary. Presentation, spelling, punctuation and grammar are such that the intended meaning is not clear.

[1]−[3]



AVAILABLE MARKS

103

7 (a) Parity bits A bit is added to a group of bits to make its sum odd (or even) [1] Example: the 8th bit in a byte will be the parity bit [1] When a byte is transmitted its parity is checked [1] If the parity of the byte has changed, at least one bit in the byte has

flipped [1] but an even number of flips will not be detected [1]

Any four points [4]

CRC This is a special checksum [1] applied to a block of data [1]. An

algorithm or polynomial [1] is applied to the block and the checksum appended to the block [1]. The recipient applies the same algorithm to the block and compares its result with the result already appended [1]. If they do not agree, the data has not been received successfully [1]

Any four points [4]

(b) SSL This is secure protocol [1] for financial transactions over the Internet

[1]. This enables an encrypted link between two computers on a network [1]. It enables a browser to identify the web server with which it is communicating [1]. It uses an SSL Certificate [1]

Any four points [4]

Digital certificate A digital code is generated [1] authenticated [1] by public key

encryption [1] and attached to an electronically transmitted document [1] to verify its contents [1] and the sender’s identity [1]

Any four points [4]

Total

16

150


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CCEA GCE Specimen Assessment Material for Digital Technology

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