A pretest may be used in an experiment

A pretest may be used in an experiment
 
  a. as a matching variable. c. when change is being investigated.
  b. to assess group equivalence. d. All of these are true.

Ques. 2

A researcher obtains chemistry achievement test scores from a group of high school students who have had laboratory experience and a group who have not. She recognizes the need to control for the variable intelligence in his study. Identify the type of control technique illustrated by the following procedures. The researcher enters the IQ scores into her analysis to determine both main and interaction effects of IQ and lab experiences.
 
  a. match
  b. use analysis of covariance
  c. use a homogeneous group
  d. add intelligence as an additional independent variable

Ques. 3

The group to which a researcher wants the findings to ultimately apply is the
 
  a. accessible population. c. target population.
  b. sample. d. probability sample.