Unit 2

Question 1

Hindsight bias

Answer 1

The tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon).

Question 2

Theory

Answer 2

An explanation using the integrated set of principles that organizes observations and predicts behaviors or events.

Question 3

Hypothesis

Answer 3

A testable prediction, often implied by a theory.

Question 4

Operational definition

Answer 4

A carefully worded statement of the exact procedures (operations) used in a research study. For example, human intelligence may be operationally defined as what an intelligence test measures.

Question 5

Replication

Answer 5

Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding can be reproduced.

Question 6

Case study

Answer 6

A descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles.

Question 7

Naturalistic observation

Answer 7

A descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.

Question 8

Survey

Answer 8

A descriptive technique for obtaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.

Question 9

Sampling bias

Answer 9

A flawed sampling process that produces an unrepresentative sample.

Question 10

Population

Answer 10

All those in a group being studied, from which samples may be drawn.

Question 11

Random sample

Answer 11

A sample that fairly represents a population because each member has an equal chance of inclusion.

Question 12

Correlation

Answer 12

A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.

Question 13

Correlation coefficient

Answer 13

A statistical index of the relationship between two things (from -1.00 to +1.00)

Question 14

Variable

Answer 14

Anything that can vary and is feasible and ethical to measure.

Question 15

Scatterplot

Answer 15

A graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation).

Question 16

Illusory correlation

Answer 16

Perceiving a relationship where none exists, or perceiving a stronger-than-actual relationship.

Question 17

Regression toward the mean

Answer 17

The tendency for extreme or unusual scores or events to fall back (regress) toward the average.

Question 18

Experiment

Answer 18

A research method in which an investigar manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable.) By random assignment of participants, the experimenter aims to control other relevant factors.

Question 19

Experimental group

Answer 19

In an experiment, the group exposed to the treatment, that is, to one version of the independent variable.

Question 20

Control group

Answer 20

In an experiment, the group not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Question 21

Random assignment

Answer 21

Assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups.

Question 22

Double-blind procedure

Answer 22

An experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.

Question 23

Placebo effect

Answer 23

Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.

Question 24

Independent variable

Answer 24

In an experiment, the factor that is manipulated; the variable whose effect is being studied.

Question 25

Confounding variable

Answer 25

A factor other than the factor being studied that might influence a study’s results.

Question 26

Dependent variable

Answer 26

In an experiment, the outcome that is measured; the variable that may change when the independent variable is manipulated.

Question 27

Validity

Answer 27

The extent to which a test or experiment measures or predicts what it is supposed to.

Question 28

Informed consent

Answer 28

Giving potential participants enough information about a study to enable them to choose whether they wish to participate.

Question 29

Debriefing

Answer 29

The postexperimental explanation of a study, including its purpose and any deceptions, to its participants.

Question 30

Descriptive statistics

Answer 30

Numerical data used to measure and describe characteristics of groups. Includes measures of central tendency and measures of variation.

Question 31

Histogram

Answer 31

A bar graph depicting a frequency distribution.

Question 32

Mode

Answer 32

The most frequently occurring score in a distribution.

Question 33

Mean

Answer 33

The arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores.

Question 34

Median

Answer 34

The middle score in a distribution; half the scores are above it and half are below it.

Question 35

Skewed distribution

Answer 35

A representation of scores that lack symmetry around their average value.

Question 36

Range

Answer 36

The difference between the highest and lowest scores in a distribution.

Question 37

Standard deviation

Answer 37

A computed measure of how much scores vary around the mean score.

Question 38

Normal curve

Answer 38

(Normal distribution) A symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (about 68% fall within one standard deviation of it) and fewer and fewer near the extremes.

Question 39

Inferential statistics

Answer 39

Numerical data that allow one to generalize–to infer from sample data the probability of something being true of a population.

Question 40

Statistical significance

Answer 40

A statistical statement of how likely it is that an obtained result occurred by chance.