Chapter 8: Experiments

Question 1

At the most basic level, experiments involve

Answer 1

(1) Taking action and (2) observing the consequences of that action

Question 2

What are natural experiments?

Answer 2

Experiments that occur in the regular course of social events

Question 3

What three major pairs of components do most conventional experiments have?

Answer 3

(1) Independent variables and dependent variables, (2) pre-testing and post-testing, and (3) experimental and control groups

Question 4

What is a dichotomous variable?

Answer 4

A variable with two attributes–present and not present

Question 5

What is pretesting?

Answer 5

The measurement of a dependent variable among subjects before they are exposed to a stimulus representing and independent variable

Question 6

What is post-testing?

Answer 6

The remeasurement of a dependent variable among subjects after they’ve been exposed to a stimulus representing an independent variable

Question 7

What is the Hawthorne effect?

Answer 7

The effect of the experiment rather than the stimulus the experiment seeks to measure on people

Question 8

What is a double-blind experiment?

Answer 8

An experimental design in which neither the subjects nor the experimenters know which is the experimental group and which is the control group

Question 9

A technique for assigning experimental subjects to experimental and control groups randomly

Answer 9

Randomization

Question 10

In connection with experiments, the procedure whereby pairs of subjects are matched on the basis of their similarities or one or more variables, and one member of the pair is assigned to the experimental group and the other to the control group.

Answer 10

Matching

Question 11

Refers to the possibility that the conclusions drawn from experimental results may not accurately reflect what went on in the experiment itself.

Answer 11

Internal validity

Question 12

Refers to the possibility that conclusions drawn from experimental results may not be generalizatnle to the “real” world

Answer 12

External invalidity

Question 13

A formal experiment conducted outside the laboratory, in a natural setting

Answer 13

Field Experiment

Question 14

What are the three pre-experimental designs that Stanley and Campbell identify?

Answer 14

(1) One shot case study, (2) One-group pretest-posttest design, and (3) Static group comparison

Question 15

What is a one-shot case study?

Answer 15

A single group of subjects is measured on a dependent variable following the administration of some experimental stimulus. There is no control group and no pre-test. (A man who exercises is observed to be in trim shape)

Question 16

What is a one group pre-test-post-test?

Answer 16

The pre-test is given to either the experimental group or control group but not to both groups. (An overweight man who exercises is later observed to be in trim shape.

Question 17

What is a static group comparison?

Answer 17

There is an experimental group and a control group but no pre-test. (A man who exercises is observed to be in trim shape while one who doesn’t is observed to be overweight.)

Question 18

What are the four groups in Solomon’s Four-Group Design?

Answer 18

Group 1: Experimental group with pre-test and post test; Group 2: Control group with pre-test and post-test; Group 3: Experimental group with pre-test only; Group 4: Control group with post-test only

Question 19

Experiments measure

Answer 19

The effect of an independent variable on a dependent variable.

Question 20

What are 8 sources of internal validity that need to be considered?

Answer 20

(1) History, (2) Maturation, (3) Testing, (4) Instrumentation, (5) Statistical Regression, (6) Selection Bias, (7) Experimental Mortality, (8) Demoralization

Question 21

During the course of the experiment, historical events may occur that confound the experimental results

Answer 21

History validity concern

Question 22

People are continually growing and changing, and such changes affect the results of the experiment

Answer 22

Maturation validity concern

Question 23

Often the process of testing and retesting influences people’s behavior, thereby confounding experimental results

Answer 23

Testing validity concern

Question 24

The process of measurement in pre-testing and post-testing brings in some of the issues of conceptualization and operationalization (ex. using different questionnaires to measure the same variable and mixing results)

Answer 24

Instrumentation validity concern

Question 25

It is also known as regression to the mean. This threat is caused by the selection of subjects on the basis of extreme scores or characteristics. Give me forty worst students and I guarantee that they will show immediate improvement right after my treatment.

Answer 25

Statistical regression validity concern

Question 26

The biases which may result in selection of comparison groups. Randomization (Random assignment) of group membership is a counter-attack against this threat.

Answer 26

Selection bias validity concern

Question 27

The loss of subjects. For example, in a Web-based instruction project entitled Eruditio, it started with 161 subjects and only 95 of them completed the entire module. Those who stayed in the project all the way to end may be more motivated to learn and thus achieved higher performance.

Answer 27

Experiment mortality validity concern

Question 28

Feelings of deprivation within the control group that result in members giving up.

Answer 28

Demoralization validity concern