Failure of an independent variable to produce changes in a dependent variable is called a
a. statistical error.
b. failure to replicate.
c. null result.
d. confound.
Which of the following is not a type of quasi-experimental design?
a. nonequivalent control group posttest-only design
b. correlated-groups design
c. multiple-group time-series design
d. nonequivalent control group pretest/posttest design
A recent study reports that the more sexual content that adolescents watch on TV, the more likely they were to engage in sexual behaviors. However, it is unclear whether the sexual content on TV leads to sexual behavior or whether sexual behavior leads to a preference for sexual content on TV. This is an example of the third-variable problem.
a. True
b. False
Indicate whether the statement is true or false
A(n) _______________ indicates the lower and upper bounds of the estimate of a statistic.
Fill in the blank(s) with correct word
Which of these is NOT a possible explanation for obtaining null results in a valid experiment?
a. the levels of the independent variable are too similar to each other.
b. the experimenter used a valid and reliable measure of the dependent variable.
c. the manipulation of the independent variable was unsuccessful..
d. the dependent variable is subject to a floor effect.
In _____ designs, many measures are taken so that the effect of the treatment can be seen over time.
a. pretest-posttest
b. single-group
c. nonequivalent control group
d. time-series
An experiment always involves comparing measurements obtained under one level of the independent variable with measurements obtained under another level of the independent variable.
a. True
b. False
Indicate whether the statement is true or false
The difference between nonprobability and probability sampling is that nonprobability sampling does not involve _______________ and probability sampling does.
Fill in the blank(s) with correct word
General practice effects in within-subjects experiments include
a. boredom.
b. fatigue.
c. learning.
d. all of these.
Which of the following is true concerning the nonequivalent control group pretest/posttest design?
a. Comparisons can be made between groups on the pretest and the posttest.
b. Comparisons can be made within groups from the pretest to the posttest.
c. Because participants are not randomly assigned to groups, we cannot say that they are
d. all of the above