According to Freud, trying to prevent a drive from being expressed weakens that drive

The problem with a survey that is not representative is that

a. it is unfair not to give everyone an equal chance to participate. b. the data will be limited in its reliability. c. the rules governing random assignment have been violated. d. the researcher will not be able to draw valid conclusions about the population.

Researchers pilot test independent variables to

a. see whether they affect the dependent variable b. eliminate error variance c. look for confounds d. determine whether participants can detect differences in the levels e. allow confederates to practice their roles