Because of the limitations of ex post facto research, it should

Because of the limitations of ex post facto research, it should
 
  a. rarely be used in educational research.
  b. be interpreted with caution.
  c. be used carefully by those interested in important variables which cannot be manipulated.
  d. be replaced by analysis of variance techniques.
  e. b and c.

Ques. 2

A researcher is interested in whether playing soft music increases worker productivity in a factory. This illustrates ____ research, and music is the ____.
 
  a. correlational; dependent variable c. experimental; independent variable
  b. correlational; independent variable d. experimental; dependent variable

Ques. 3

In which of the following, is ex post facto research most appropriate? The investigator
 
  a. has direct control of the dependent variables.
  b. cannot manipulate the dependent variables.
  c. cannot manipulate the independent variables.
  d. can cause variations on all variables.