Lecture 5 - Quantitative Research

8/12/2019 Lecture 5 - Quantitative Research

1/21

School of Healthcare

Research Approaches 2:Quantitative research

How many versushow well

Ian Grigor


2/21


AimTo understand the role of

quantitative research


3/21


Objectives To understand the principle of

research methods adopting a

quantitative approach (basicallyinvolving experimental design)

To interpret the role of quantitativeresearch

To comment on the strengths andweaknesses of quantitative research


4/21


The generation ofinformationandunderstanding

(perhaps)

consisting ofas opposed to

unsupported

opinion

New concepts

New models

New theories

So we need evidenceas opposed to

anecdote

Determinants arevalidityreliability

generalisability

What is research?


5/21


Quantitative research traditions

Focus predominantly (though notexclusively) on experimental design. Agood example might be a survey

questionnaire Experimental design has long been

perceived as the gold standard formedically-orientated research

Rely largely on statistical measures andrequire larger samples and morestructured data collection tools (Polit et al2001)


6/21


Why and when do we prefer totalk in quantitative terms? We like to quantify things because

we have an awareness of scales

Theres an element of valueattached to a quantity

When were being professional

When its necessary to get a message

across


7/21School of Healthcare

What is quantitativeresearch?

Burns & Grove (1987)

... a formal, ob ject ive, systematic

process in which numer ical data are

ut i l ized to ob tain informat ion about

the wo r ld" and" a research method

which is used to descr ibe and testrelat ionsh ips and to exam ine cause-

and-effect relat ion sh ips".



Elements of quantitativeresearch

Tests and experiments under

controlled conditions

Cause and effect relationships(Alderson 1998)

Gathering numerical data objectively

Results lend themselves to statisticalanalyses

Evaluation of results confirm or

refute the original hypothesis



Elements of quantitative research can bedescribed as positivist paradigms

Quantitative data

Statistical analysis within definitiveconcepts (logical mathematics)

Atomistic (focusing on component parts)

Studying discrete relationships

Being of low complexity???

Potentially seeking to explain laws Requiring control subjects/sets

Ultimately, we should understand what wedont know at present!!



Samples for study

Your sample is the group of cases (people,organisations, etc.) that you study in yourresearch

It should be either comprehensive i.e.everyone or a selection that is trulyrandomised, inclusive and controlled

It should not be a limited study of 12 (cfWakefield et al1994: 1998: 2001) unlessthat is all that is in the population underscrutiny



In relation to our ongoingMMR theme

Studies by Gillberg & Heijbel (1998); Honda (2005);Peltola et al(1998); Taylor et al(1999)

quanti f iedthe number of doses of MMR givenover a period of time in a specific country or area

and also quanti f iedthe number of cases ofautism diagnosed in the population given the

MMR vaccine. Then, using stat ist icaltesting todetermine whether there was any evidence of an

association between these variables (MMR andautism), they tried to ascertain the strength of the

association: this is quant i tat iveresearch



Using Wakefields work on theMMR debate as our metaphor

The information and understandinggenerated was highly questionable

His opinions have been heavily criticised

His claims were based on a study of 12children

A Scandinavian study of 300,000 came tothe opposite conclusion

Any comments aboutgeneralisability?



Validity of data generation

Do your data relate to the concepts youthink they do?

What steps were taken to tackle these

issues? Convince the reader that youvethought about this and confront the issue

Are your data appropriate? Is the combination of methodology and the

cases under study able to generate the datarequired for the study?

Could there be extrinsic factors influencingyour results?


14/21


Validity

Are hidden factors at play?

You think youre looking at the effects of

X but other factors youre unaware ofare really what are affecting the situation

Your explanation applies to muchof

your data even though you soughtnegative instances/ alternatives


15/21


Reliability

Could another researcher repeat this

work, using the same data, and end

with the same result? Have you consistently used

standardised protocols and

techniques?


16/21


17/21


Strengths of quantitativeresearch

You can manipulate your numbers to

create visual images e.g. graphs

Concepts can be measured and directly

compared to previous/subsequent work

There may be direct correlation between

cause and effectthis is the ideal

It may be possible to generalise towardsexternal validity i.e. predict

Breadth of coverage of big population


18/21


Weaknesses of quantitativeresearch

The whole may not be equal to thesum of the parts

Lack of depth i.e. looking at just onepart of the whole

Defining everything, in terms ofnumbers, is risky when dealing withhumans especially

Ultimately, everything is qualitative!


19/21


The final evidence on the MMRcontroversy

The evidence is that MMR is not assoc iated

with autism in childrenthe quality,

val id i ty and s ize of that evidence isoverwhelmingautism rates began to rise

before MMR

Anon(2005) MMR vacc inat ion and aut ism

Available at www.ebandolier.com

The worldwide studies on this topic have

covered some 2 million people


20/21


References

Alderson P (1998) The importance oftheories in health care Bri t ish Medical

Journal317, 1007-10 Hek G, Judd M and Moule P (2002)

Making sense of research : an

int roduct ion fo r heal th and social

care pract i t ioners (2ndedit ion )

London: Continuum


21/21


Objectives To understand the principle of

research methods adopting a

quantitative approach To interpret the role of quantitative

research

To comment on the strengths andweaknesses of quantitative research

Date post:	03-Jun-2018
Category:	Documents
Upload:	shakeelzafar
View:	215 times
Download:	0 times

Lecture 5 - Quantitative Research

Documents