Exam 10: Experimental Research

Events or influences other than the experimental treatment itself may occur between a pretest and a posttest that may affect the dependent variable.This threat is called

An experimenter bias effect operates when an experimenter

Exhibit 10-3: Choose the type of experimental validity that is being referred to in the following questions. -Refer to Exhibit 10-3.Were the tests used for analysis appropriate and sufficiently powerful to correctly estimate the size and significance of the effect?

A researcher is interested in whether playing soft music increases worker productivity in a factory.This illustrates ____ research, and music is the ____.

Consider the following: "To what group of subjects can the research results based on this particular sample be generalized?" This question is concerned with

An experimenter was interested in the effect of caffeine on a performance test.Three equivalent groups consumed high, moderate, or low amounts of caffeine before taking the performance test.This experiment had

Randomization in an experimental design assures

Exhibit 10-5: Choose the internal validity problem that is associated with the situations listed. -Refer to Exhibit 10-5.Extreme scores move toward the mean.

A confounding variable is one which

Exhibit 10-8: Choose the term that is described in each of the phrases below. -Refer to Exhibit 10-8.All subjects have IQ scores in the average range (90-110).

The major benefit of random assignment is it

Matching of experimental and control subjects, homogeneous selection, and analysis of covariance can all be used to

Exhibit 10-9: Identify the threats to internal validity illustrated in the examples below. -Refer to Exhibit 10-9.Preschoolers who received treatment for stuttering during the year show a significant improvement in articulation.

Exhibit 10-10: Identify the major threat to internal validity in the following research studies. -Refer to Exhibit 10-10.A researcher conducted a semester-long experiment comparing two instructional programs in math.During the administration of tests during the semester, the researcher found that about ten percent of the experimental group and about five percent of the control group were absent for each administration.

Exhibit 10-6: Choose the intersubject difference control that best corresponds with the following statements. -Refer to Exhibit 10-6.A teacher flips a coin for each child to determine if the child will be in the control or experimental group.

Exhibit 10-10: Identify the major threat to internal validity in the following research studies. -Refer to Exhibit 10-10.Students who had low scores on a reading pretest were chosen for a special instructional program.This group showed significant gains on a reading achievement test administered after a period of four months.

The control of experimenter effect in a research study can be accomplished by

Exhibit 10-10: Identify the major threat to internal validity in the following research studies. -Refer to Exhibit 10-10.A teacher researcher randomly assigned students within a classroom to two groups, one of which received some special instructional materials to take home with them to study and to use with homework assignments.The C group did not get the special materials.The researcher was surprised to find that there weren't significant differences between the two groups on achievement tests and other selected measures.

Exhibit 10-7: Identify the threats to internal validity illustrated in the example below. -Refer to Exhibit 10-7.The students scored much higher on the posttest because the posttest was easier than the pretest.

The fact that people may learn from test taking is an experimental validity threat known as ____; the fact that the measurement scale may change over the course of the experiment is called ____.