Studied by 11 people
Multivariate Designs
involve more than two variables
Covariance
are the variables related
Temporal Precedence
does one variable cause the other variable
Internal Validity
is there a 3rd variable that might explain the relationship of the first two variables
Developmental designs
how do the relationships between variables change over time
Multiple regression designs
how do other variables affect the relationship between the variables of interest
Cohort effects
People who are born at different times may experience very different environmental influences
Longitudinal
Same person tested over prolonged period of time
Cross-sectional correlations
whether two variables measured at the same point at the same point in time are correlated
Auto-correlations
the correlation of each variable with itself across time - but cannot examine between variable influences
Cross-lag correlations
the degree to which an earlier measure of one variable is correlated with a later measure with the other variable
Predictor variable
Independent variable and 3rd variable
Criterion variable
dependent variable
Regression Coefficient
Called Beta and Indicates how well it predicts the criterion variable controlling for all other predictors
Mediation
What specific aspect of a variables causes it to be associated with another variable
Moderation
The presence of subgroups has implication for external validity
Confound
Alternative explanations that threaten internal validity
Systematic
Internal validity only threatened
Unsystematic
random, makes it difficult to see DV, but not a confound
Moderator
3rd variable that affects the correlation between the variables of interest
Mediator
any variables that explains the indirect relationship between two other variables
Experimental research
correlation does not equal causation
Placebo effect
When control condition is so convincing, it has an effect on DV
Selection effects
Participants in one group systematically differ from those in other
Between subject/groups
each different person/group of people has a different version of the IV
Within subject/groups
responses from a single group are compared across all versions of the IV
Post-test only
DV is measured only after exposure to the IV
Pretest - post-test
DV is measured both before and after exposure to the IV
Concurrent measures design
DV measured after all versions of the IV are presented simultaneously
Repeated measures design
DV measures after successive exposure to all versions of the IVs
Maturation threats
when participants development or passage time causes a change in their behavior (not IV)
History threats
when an external event affects the DV happens at the same time as the IV
Regression threats
when scores become less extreme over time
Time interval threats
Maturation
History
Regression
Repetition threats
Attrition threats
Instrumentation threats
Testing threat
Attrition threats
when participants drop out of a study in a non-random fashion; change due to changes in the composition group
Instrumentation threats
when scores change because the DVs change at each measurement/over time; people change because of change in the DV not IV
Testing threats
when scores change because of previous experience with the DV
Null-effects
effects not found:
not enough between groups variance
too much within groups variance
IV has no effect
Null effects for between-groups variance
less is bad
Null effects for within-groups variance
more is bad
