Chapter 7&8 Flashcards
- participants are in different conditions
- Can’t place people in their condition, it’s predetermined
- To show causation you have to create equivalent groups through random assignment
between subjects
- Requires fewer participants
- Sensitive to small differences between means
- Use counterbalancing
Within Subjects
T-Test: two or more conditions
- compares the means of two groups
- Assumptions
- Normal distribution, interval or ratio data
- Homogeneity of variance
Independent groups (sample)
the participants in conditions are not
connected to each other in any sort of way
When would independent groups (sample T test) be used
- Between subjects
- Random assignment
- Participant variables
Dependent groups (paired sample)
the participants are connected to
each other
When to use dependent groups (paired sample)
Between subjects
■ Matched groups design
■ Dyads
○ Within subjects
■ Manipulated variables
■ Repeated measures
Uses of single factor
Discover nonlinear (curvilinear) effects
■ Three levels of arousal (low, moderate, high)
○ Test specific alternative hypothesis
Interpolating:
you make estimates between points on a graph
Extrapolating:
you make estimates outside points on a graph
Multiple T-Tests:
increases likelihood of type I error
ANOVA:
comparing group means
IV is continuous:
line graph preferred, bar graph
acceptable
IV is discrete:
use a bar graph, line graph is inappropriate
factor
independent variable
factorial design
2 or more independent variable
Levels
manipulation of IV
Conditions
What participants experience
cells
correspond to participant condition
main effect
effect of single of IV
Interactions
- main advantage of factorial design
- effect of 1 IV depends on the level of another IV
Matched group design
Matching procedure followed by random assignment
Ex-post facto design
Subjects in the study are placed in the groups after the fact of their already existing subject characteristics
Repeated measures design
When the independent variable is tested within subjects-that is each participant in the study experiences each level of the independent variable
