Midterm 2

Question 1

situational independent variable

Answer 1

manipulates situation, example: relaxation or no relaxation

Question 2

task independent variable

Answer 2

manipulates task, example: solving anagrams or puzzles

Question 3

instructional independent variable

Answer 3

manipulates instructions, example: solving with time limit or no time limit

Question 4

statistical conclusion validity

Answer 4

proper analyses and conclusions, respect test assumptions, right type of measures

Question 5

construct validity

Answer 5

well operationalized independent and dependent variable

Question 6

internal validity

Answer 6

confound free

Question 7

external validity

Answer 7

how well can results be generalized to other populations, other environments (ecological validity), and other times

Question 8

most important type of validity

Answer 8

construct and internal validity

Question 9

pre and post studies, what could cause changes other than IV?

Answer 9

1) history
2) maturation
3) regression to the mean
4) attrition

Question 10

subject selection effect

Answer 10

subjects might select themselves into certain groups without random assmt. Monkey ulcer study

Question 11

between subjects study necessary when…

Answer 11

1) studying subject variable

2) when subjects have to be naive

Question 12

which random assmt method to use with between group study

Answer 12

1. )block randomization-assign participants randomly to all conditions in the block and repeat until all participants have been assigned
2. )matching-use when small number of ppl

Question 13

when to use matching

Answer 13

small number of ppl

Question 14

problems with within-subjects design

Answer 14

1) order could influence results: progressive effects, sequence effects
2) performance improves over time: practice effects
3) fatigue, performance decreases

Question 15

complete counterbalancing

Answer 15

way to avoid sequence effects, all possible conditions. For example, 3 conditions=3! within-subjects

Question 16

partial counterbalancing

Answer 16

random sample of all possible combinations. Within-subjects

Question 17

block randomization

Answer 17

totally random within block. Within-subject and between-subject

Question 18

reverse counterbalancing

Answer 18

a-b-c-d-d-c-b-a. Within-subject

Question 19

ceiling effect

Answer 19

average scores for the group are so high that no difference can be determined between conditions

Question 20

floor effect

Answer 20

all scores are extremely low

Question 21

examples of ways to lose internal validity

Answer 21

• take place over long period over time (attrition)
• subject groups non-equivalent (subject selection effect)
• no control group

Question 22

Hawthorne effect

Answer 22

When behavior is affected by the knowledge that one is in an experiment

Question 23

cohort effects

Answer 23

groups differ in terms of environment in which they were aged, not just age

Question 24

demand characteristics

Answer 24

aspects of the study that reveal hypothesis being tested

• might be a reason to use between subject design
• can use manipulation checks

Question 25

independent groups design

Answer 25

b/w groups, manipulated variable, random assignment

Question 26

matched groups design

Answer 26

b/w groups, matched assignment, manipulated variable

Question 27

ex post facto/nonequivalent groups design

Answer 27

subject variable, b/w groups, deliberate non-equivalence

Question 28

within-subject if subject is tested once. How to randomize?

Answer 28

full or partial counterbalancing AB or BA

Question 29

within-subject if subject is tested more than once. How to randomize?

Answer 29

reverse/block counterbalancing ABBA

Question 30

placebo control group

Answer 30

subjects think they are being treated

Question 31

waiting list control group

Answer 31

receive treatment after study is over

Question 32

yoked control group

Answer 32

control group yoked to experimental subject

Question 33

ANOVA: when to use?

Answer 33

more than two-levels in design

Question 34

types of ANOVA

Answer 34

one-way:one independent variable

two way: two independent variables

Question 35

what do you need to calculate ANOVA?

Answer 35

mean and number of subjects in each level

Question 36

F ratio

Answer 36

variance between groups/variance within groups

Question 37

Variance between groups

Answer 37

sum of squares between groups/degree of freedom between groups

Question 38

Variance within groups

Answer 38

sum of squares within groups/degree of freedom within groups

Question 39

reinforcement delay

Answer 39

between groups variance

Question 40

error

Answer 40

within groups variance

Question 41

multilevel design advantages for between-subject designs

Answer 41

1) can reveal nonlinear results

2) can rule out alternative explanations

Question 42

multilevel design advantages for within-subject designs

Answer 42

1) can reveal nonlinear results

2) all counterbalancing options available

Question 43

when is t-test used

Answer 43

single factor, two level design

Question 44

t-test for independent groups

Answer 44

manipulated IV, subject IV

Question 45

t-test for dependent groups

Answer 45

matched groups, within-subjects design

Question 46

t-test formula

Answer 46

(mean x1-mean x2)/standard error of difference

Question 47

df formula

Answer 47

n1+n2-2

Question 48

Cohen’s d, calculates effect size

Answer 48

difference in mean/standard deviation for both groups combined

difference in mean/s