CATALYST

1.Pick up your quiz #3 from the front of your graded work folder.

2.Update your quiz tracker!3.Catalyst: List some things that you have control over when you conduct an experiment.

SCIENTIFIC INQUIRYCONTROLS & GATHERING DATA

CONTROLS & GATHERING DATA 09.08.2008

TYPES OF EXPERIMENTAL CONTROLS (1)

1) Experimental group versus Control groups

Experimental group:  treatment Control group: no treatment

Control group is necessary for a comparison

EXAMPLE OF TYPE 1Study What are the effects of vitamin C supplements

onthe number of colds a person gets per year?

Experimental GroupParticipants are given a vitamin C tablet

Control GroupParticipants in this group are not given anyvitamin tablet

CONTROLS & GATHERING DATA 09.08.2008

Control Types

1. Experimental Group (treatment) vs. Control Group (no treatment)

Ex. Vitamin C tablet vs. no tablet

TYPES OF EXPERIMENTAL CONTROLS (2)

2) Control over the levels or values of the independent variable

REMEMBER: Independent Variable: the variable you

are able to CHANGE or CONTROL Dependent Variable: that you can

measure which is affected by the independent variable

EXAMPLE OF TYPE 2Study What are the effects of vitamin C supplements

onthe number of colds a person gets per year?

Independent Variable The variable that we can change is the vitamin

C We can CONTROL or CHANGE the value of

vitamin C Changing the amount in each tablet

250 mg, 500 mg, 1000 mg Giving the same independent

variable to each participant

CONTROLS & GATHERING DATA 09.08.2008

Control Types

1. Experimental Group (treatment) vs. Control Group (no treatment)

Ex. Vitamin C tablet vs. no tablet

2. Control over levels/values of IV Ex. Amount of Vitamin C

TYPES OF EXPERIMENTAL CONTROLS (3)

3) Control over the experimental

setting

Preventing extraneous variables

EXAMPLE OF TYPE 3Controlling the noise in an

auditory perception experiment (how well people can hear)

CONTROLS & GATHERING DATA 09.08.2008

Control Types

1. Experimental Group (treatment) vs. Control Group (no treatment)

Ex. Vitamin C tablet vs. no tablet

2. Control over levels/values of IV Ex. Amount of Vitamin C3. Control over exp. Setting Ex. Noise level in exp.

TYPES OF EXPERIMENTAL CONTROLS (4)

4) Control Variable

A potential independent variable that is held constant across conditions in an experiment.

EXAMPLE OF TYPE 4

4) Control Variable

Question: Does the mass of a pencil affect the time it takes to fall to the ground?

Control Variable: You would drop the pencil from the same

height for every experiment.

Why?

CONTROLS & GATHERING DATA 09.08.2008

Control Types

1. Experimental Group (treatment) vs. Control Group (no treatment)

Ex. Vitamin C tablet vs. no tablet

2. Control over levels/values of IV Ex. Amount of Vitamin C3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held

constant/same in all trials Ex. Height of pencil in time

vs. mass exp.

The experimenter has an obligation to report ALL the results of an

experiment, NOT just those that support his/her hypothesis.

GATHERING DATAOBSERVE

CONTROLS & GATHERING DATA 09.08.2008

Control Types

Gathering Data

3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held

constant/same in all trials Ex. Height of pencil in time

vs. mass exp.

- Must report ALL data

GATHERING DATA ORGANIZE

Prepare a data table in your laboratory notebook

A data table ensures consistencyMakes it easier to analyze your results

TIPS FOR TABLE MAKING

Put a title at the top of every table Briefly describe what is contained

in the table. Include a table number at the start

of the table (such as Table 1.)

CONTROLS & GATHERING DATA 09.08.2008

Control Types

Gathering Data

3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held

constant/same in all trials Ex. Height of pencil in time

vs. mass exp.

- Must report ALL data- Create tables

- Title @ top

Use plain numbers. The units should go in the title instead of putting letters next to the numbers.

Don’t skip lines.

Label the columns and rows.

TIPS FOR TABLE MAKING

CONTROLS & GATHERING DATA 09.08.2008

Control Types

Gathering Data

3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held

constant/same in all trials Ex. Height of pencil in time

vs. mass exp.

- Must report ALL data- Create tables

- Title @ top- Label units @ top

Keep all the units the same Example: instead of 2 min 30 sec,

put 150 seconds

Use decimals, not fractions.

TIPS FOR TABLE MAKING

CONTROLS & GATHERING DATA 09.08.2008

Control Types

Gathering Data

4. Control Variable – held constant/same in all trials

Ex. Height of pencil in time vs. mass exp.

- Must report ALL data- Create tables

- Title @ top- Label units @ top

- Keep all units same

Need to have IV on left column & DV on right column!

TIPS FOR TABLE MAKING

CONTROLS & GATHERING DATA 09.08.2008

Control Types

Gathering Data

4. Control Variable – held constant/same in all trials

Ex. Height of pencil in time vs. mass exp.

- Must report ALL data- Create tables

- Title @ top- Label units @ top

- Keep all units same - IV on left; DV on right

EXAMPLE 1Hours of a Day Spent on Activities

Activity Hours

Sleep 6

School 6

Job 4

Entertainment

4

Meals 2

Homework 2

IV DV

EXAMPLE 2IV DV

EXAMPLE 3IV DV

CONTROLS & GATHERING DATA 09.08.2008

Control Types

Gathering Data

4. Control Variable – held constant/same in all trials

Ex. Height of pencil in time vs. mass exp.

- Must report ALL data- Create tables

- Title @ top- Label units @ top

- Keep all units same

PRACTICE (LEFT PAGE)Make a table that measures the number

of people in this classroom that have a birthday in each month.

YOU HAVE FOUR MINUTES TO GATHER THIS DATA.

PRACTICE (LEFT PAGE)Make a table that measures the number of people

in this classroom that have a birthday in each month.

Birth Month # People in Class

Jan.

Feb.

Mar.

Apr.

May

June.

July

August

Sept.

Oct.

Nov.

Dec.

IV DV

TABLE 1: # People in Class w/ Certain Birth Months.

SUMMARYTake 3 minutes to write a summary of today’s notes.

When done, work on your homework packet!