Chapter 5 - Intro to Experimental Research

Question 1

Experiment

Answer 1

A research procedure in which some factor is varied, all else is held constant, and some result is measured.

Question 2

Independent Variables

Answer 2

The factor of interest to the researcher; it can be directly manipulated by the experimenter (e.g., creating different levels of anxiety in subjects), or participants can be selected by virtue of their possessing certain attributes (e.g., selecting two groups that differ in normal anxiety).

Question 3

Field Experiments

Answer 3

An experiment conducted outside the laboratory; a narrower term than field research.

Question 4

Situational Variables

Answer 4

Type of independent variable in which subjects encounter different environmental circumstances (e.g., large versus small rooms in a crowding study).

Question 5

Task Variables

Answer 5

Type of independent variable in which participants are given different types of tasks to perform (e.g., mazes that differ in level of difficulty).

Question 6

Instructional Variables

Answer 6

Type of independent variable in which participants are given different sets of instructions about how to perform (e.g., given a list of stimuli, groups might be told to process them in different ways).

Question 7

Experimental Group

Answer 7

In a study with an identified control group, the experimental group is given the treatment being tested.

Question 8

Control Group

Answer 8

A group not given a treatment being evaluated in a study; provides a means of comparison

Question 9

Extraneous Variables

Answer 9

An uncontrolled factor not of interest to the researcher but that could affect the results.

Question 10

Confound

Answer 10

An extraneous variable that covaries with the independent variable and could provide an alternative explanation of the results.

Question 11

Dependent Variables

Answer 11

Behavior measured as the outcome of an experiment.

Question 12

Ceiling Effect

Answer 12

Occurs when scores on two or more conditions are at or near the maximum possible for the scale being used, giving the impression that no differences exist between the conditions. - usually, task is easy

Question 13

Floor Effect

Answer 13

Occurs when scores on two or more conditions are at or near the minimum possible for the scale being used, giving the impression that no differences exist between the conditions. - usually, task is difficult

Question 14

Subject Variables

Answer 14

A type of independent variable that is selected rather than manipulated by the experimenter; an existing attribute of the individuals chosen for the study (e.g., gender).

Question 15

Statistical Conclusion Validity

Answer 15

Said to exist when the researcher uses statistical analysis properly and draws the appropriate conclusions from the analysis.

Question 16

External Validity

Answer 16

The extent to which the findings of a study generalize to other populations, other settings, and other times.

Question 17

Subject Pool

Answer 17

Group of students asked to participate in research, typically as part of an introductory psychology course requirement; sometimes called participant pool.

Question 18

Ecological Validity

Answer 18

Said to exist when research studies psychological phenomena in everyday situations (e.g., memory for where we put our keys).

high ecological validity it means that behaviour recorded within the research can be applied to everyday life. This means that the results are more useful.
Although test designs and findings in studies characterized by low ecological validity cannot be generalized to real-life situations, those characterized by high ecological validity can be.

Question 19

Internal Validity

Answer 19

The extent to which a study is free from methodological flaws, especially confounding factors.

is defined as the extent to which the observed results represent the truth in the population we are studying and, thus, are not due to methodological errors.

Question 20

Pretest

Answer 20

A measurement given to participants at the outset of a study, prior to their being treated (or not treated, if in a control group).

Question 21

Posttest

Answer 21

A measurement given to participants at the conclusion of a study after they have experienced a treatment or been in a control group; comparisons are made with pretest scores to determine if change occurred.

Question 22

History

Answer 22

A threat to the internal validity of a study; occurs when a historical event that could affect participants happens between the beginning of a study and its end.

Question 23

Maturation

Answer 23

A threat to the internal validity of a study; occurs when participants change from the beginning to the end of the study simply as a result of maturational changes within them and not as a result of an independent variable.

Question 24

Regression to Mean

Answer 24

If a score on a test is extremely high or low, a second score taken will be closer to the mean score; can be a threat to the internal validity of a study if a pretest score is extreme and the posttest score changes in the direction of the mean.

Question 25

Testing

Answer 25

A threat to the internal validity of a study; occurs when the fact of taking a pretest influences posttest scores, perhaps by sensitizing participants to the purpose of a study.

Question 26

Instrumentation

Answer 26

A threat to the internal validity of a study; occurs when the measuring instrument changes from pretest to posttest (e.g., because of their experience with the instrument, experimenters might use it differently from pretest to posttest).

Question 27

Subject Selection Effects

Answer 27

A threat to the internal validity of a study; occurs when those participating in a study cannot be assigned randomly to groups; hence the groups are nonequivalent.

Question 28

Attrition

Answer 28

A threat to the internal validity of a study; occurs when participants fail to complete a study, usually but not necessarily a longitudinal study; those finishing the study may not be equivalent to those who started it.