EPPP: Statistical and Research Design

This threat to internal validity occurs when there is a biological or psychological change within subjects over course of study.

This threat to internal validity occurs when an external event systematically affects the status of subjects on the DV.

This threat to internal validity occurs when there are practice or memory effects from subjects taking tests more than once.

This threat to internal validity occurs when there are changes in the accuracy or sensitivity of measuring devises over course of study (ex: rater’s accuracy improves over time).

This threat to internal validity occurs because of the tendency of extreme scores to regress to the mean when measure is readministered to same group of people.

This threat to internal validity occurs when

• the method used to assign subjects to treatment groups results in systematic differences between the groups at the beginning of the study (it's often a problem when intact groups are used).

This threat to internal validity occurs when there is dropout.

This threat to internal validity occurs when one group of subjects is systematically exposed to another threat to validity different from another group (example: one group of subjects is exposed to an external event [history] that other group isn't).

This sampling method involves recording at equal intervals and is good for behaviors that have no clear beginning or end.

This sampling method involves observing the behavior each time it occurs.

This samling method involves coding behavioral sequences rather than isolated behavioral events and is used for complex social behaviors.

The difference between quasi-experimental and true experimental research is ...

This sampling technique occurs when everyone has an equal cahnce of selection and the senection of one subject has no effect on the selection of another.

THis sampling technique ensures that each characteristic/ stratum is represented in the sample by dividing into strata and randomly selection from each.

• This sampling technique is useful when a researcher can't obtain access the the entire population. It id conducted by selecting units of individuals (pre-existing groups) rather than individuals and either including all from each group or random sampling from each.