which of the following characteristics of experiments are not also
characteristics of surveys?
check all that apply.
d
a. two or more treatments are compared in the study (possibly
including "no treatment").
o
b. data are gathered during the course of the study.
c. replication with other groups of subjects can improve the
reliability of the study.
o
d. one or more treatment groups and a control group are included in
the study
o
e. the results of the study are analyzed statistically.