Exam 13: Experimentation

For a study to be called an "experiment," it is necessary that the researchers have complete control over all of the relevant variables.

Which of the following is true about history effects?

Trend studies are most useful when a researcher is testing hypotheses concerning an individual's response to a control variable.

A high degree of association between two variables, such as frequency of advertising exposure and respondent advertising recall, establishes a causal relationship between the two.

A researcher studying the effectiveness of advertising copy tested various groups of randomly selected respondents.After the first interviews, the researcher modified the questionnaire for use with the remaining respondents.The results of this study may be compromised by the maturation effect.

One approach to reducing selection bias is to

In the following before-after randomized control group design, the output of interest would be the difference between 0₁ - 0₃ and O₂ - 0₄. R 0₁ X 0₂ --------------- R 0₃ 0₄

The question of whether the results of an experiment apply to the real world refers to

The following is a Solomon Four-Group design.Because groups III and IV do not have a before-measure, they cannot be regarded as experimental groups. R 0₁ X 0₂ --------------- R 0₃ 0₄ --------------- R X 0₅ --------------- R 0₆

In non-matched control group designs, one group is exposed to treatment while another is not.The response variable is measured in the two sample groups at the end of the experiment.This solves the problem of selection bias.

Descriptive studies can usually be used in place of experiments to infer and to confirm the existence of a causal relationship.

The dependent variable in this study would be sales

Which of the following designs corrects for all forms of biases in responses? a) one shot framework b) pretest-posttest descriptive framework c) pretest-posttest causal framework d) Solomon four group design e) none of the above

To infer a causal relationship, which of the following types of evidence does a researcher need?

Causation means that a change in one variable will produce a change in another

When it is not possible to make sure that groups in a study have identical characteristics before the administration of an experimental treatment, the researcher should be concerned with

The internal validity of the smoking study above is threatened by the mortality effect.

In the absence of a true experiment, there is no way to adequately control for an identified intervening variable.

As the sample size decreases, the degree of matching achieved by randomization will increase.

A researcher studying the effects of several control variables is faced with the problem of increasing sample size and increasing cost.The usual solution is the before-after design.