A control group or a control condition is included in an experiment in order toQuestion 5Answera.evaluate experimenter effects and demand effects.b.prevent ceiling or floor effects.c.increase the generalizability of the results.d.provide a baseline against which the variable of interest can be compared.

A control group is needed ________ A. To control for some rival hypothesis B. To serve as a comparison C. To control for attrition effects D. Both a and b are correct

In ________ design a single test group or area is selected and the dependent variable is measured before the introduction of the treatment. The treatment is then introduced and the dependent variable is measured again after the treatment has been introduced. The effect of the treatment would be equal to the level of the phenomenon after the treatment minus the level of the phenomenon before the treatmentChoose one optionBefore-and-after with control designBefore-and-after without control designAfter-only with control designNone

In _______ design two groups or areas (test area and control area) are selected and the treatment is introduced into the test area only. The dependent variable is then measured in both the areas at the same time. Treatment impact is assessed by subtracting the value of the dependent variable in the control area from its value in the test areaChoose one optionBefore-and-after without control designBefore-and-after with control designAfter-only with control designNone

Explain the importance of controlling variables for the validity of an experiment.

In a scientific experiment, the investigator manipulates the ______ variable(s) to determine whether it causes another variable to change.Multiple Choicestandardizedcontrol groupdependentindependentcontrol group and standardized