Mark is conducting a survey of purchasing habits and knows that some of his questions may seem tedious and repetitive. He is concerned that respondents may be careless in their responding, so his best methodological choice is a(n) ____.
a. e-mail questionnaire
b. personal interview
c. mail questionnaire
d. drop-off survey
Question 2
In an experiment, an interaction can be obtained only when
a. the experiment involves more than one independent variable.
b. the experiment involves more than one dependent variable.
c. the experiment confounds either two independent variables or two psychological processes.
d. the results depend upon the combination of the dependent variables.