The process of determining the number of representatives for each state is called ______.

If research participants are assessed with a particular questionnaire early in a study, but the researchers change the questions for later assessment so participants can't simply repeat answers, what potential thread to internal validity would be

at work here? a. instrumentation. b. testing. c. selection. d. history.

Sensitive parenting is especially vital when children have _____ temperaments.

Fill in the blank(s) with the appropriate word(s).