Exam 2 chapter 10

Question 1

Kinds of comparison groups

Answer 1

Control groups (variable thats held constant), treatment group (the other levels other than the control group), and placebo group (when the control group is exposed to an inert treatment, ex: sugar pill)

Question 2

What makes an ideal comparison group situation?

Answer 2

Just the IV should change and everything else should remain the same

Question 3

Selection effect

Answer 3

When the kinds of participants in one condition are systematically different from those in another group
ex: male vs female, first half of students to arrive to class vs second half, students in the front row vs back

Question 4

If there’s a selection effect or systematic variation, can we make a causal claim?

Answer 4

No, we can not make a causal claim regarding the IV and DV because its impossible to tell the reason for results

Question 5

What helps avoid selection effects?

Answer 5

Random assignment and not letting participants choose their own groups before the IV is applied

Question 6

Note-taking style and its effect on quiz grades: what are some control variables?

Answer 6

Everyone spread out randomly throughout the lecture hall

Question 7

design confound

Answer 7

An experimenter’s mistake in designing the independent variable happens when a second variable varies systematically along with the intended independent variable

Question 8

What is the problem with design confounds?

Answer 8

Threat to internal validity and the second variable is therefore an alternative explanation for results

Question 9

systematic variability

Answer 9

A description of when the levels of a variable coincide in some predictable way with experimental group membership creating a potential confound. Only a problem for internal validity if it shows this it is not the same as a confound

Question 10

unsystematic variability

Answer 10

A description of when the levels of a variable fluctuate independently of experimental group membership, contributing to variability within groups. Would not be a confounding variable.

Question 11

matched groups

Answer 11

An experimental design in which participants who are similar on some measured variable are grouped into sets; the members of each matched set are then randomly assigned to different experimental conditions

Question 12

What does matched groups prevent?

Answer 12

selection effects

Question 13

disadvantages to matched groups

Answer 13

The matching process requires an extra step before assigning groups; it requires more time and resources

Question 14

What happens when a causal claim has a confound?

Answer 14

It should be demoted to an association claim