of cases.
b. The marginal total of a row in a chi’‘square contingency table test is determined as
the product of the expected frequencies for that row.
c. In a contingency table test, the null hypothesis is that the variables of classification
are independent.
d. The expected number of cases in each cell in a contingency table test rest on the
assumption that the variables of classification are independent.
e. When the observations forming the cross tabulation are related as in a before’‘after
experiment, the chi’‘square contingency table is not applicable.
Which of the following is TRUE?
a. Random assignment of the test units to the experimental and control groups is the
feature that distinguishes the after-only with control group design from the static group
comparison.
b. One of the advantages of the after-only with control group is that there is no chance
for an interactive testing effect.
c. The after-only with control group design is particularly vulnerable to selection bias,
and where random assignment is not possible, it remains suspect.
d. The after-only with control group design is particularly susceptible to problems of
experimental mortality.
e. They are all true.
Which of the following might be considered disadvantages of secondary data?
a. Secondary data are more costly to collect than primary data.