Ap Psychology Chapter 2

Front 1

scientific method

Back 1

A five-step process for empirical investigation of a hypothesis under conditions designed to control biases and subjective judgements.

Front 2

empirical investigation

Back 2

An approach to research that relies on sensory experience and observation as research data.

Front 3

theory

Back 3

A testable explanation for a set of facts or observation. In science, a theory is NOT just speculation or a guess.

Front 4

hypothesis

Back 4

A statement predicting the outcome of a scientific study; a statement describing the relationship among variables in a study.

Front 5

operational definitions

Back 5

Specific descriptions of concepts involving the conditions of a scientific study. Operational definitions are stated in terms of how the concepts are to be measured or what operations are being employed to produce them.

Front 6

independent variable (IV)

Back 6

A stimulus condition so named because the experimenter changes it independently of all the other carefully controlled experimental conditions.

Front 7

random presentation

Back 7

A process by which chance alone determines the order in which the stimulus is presented.

Front 8

data

Back 8

Pieces of information, especially information gathered by a researcher to be used in testing a hypothesis. (Singular: datum)

Front 9

dependent variable (DV)

Back 9

The measured outcome of a study; the responses of the subjects in a study.

Front 10

replicate

Back 10

In research this refers to doing a study over to see whether the same results are obtained. As a control for bias, replication is often done by someone other than the researcher who performed the original study.

Front 11

experiment

Back 11

A kind of research in which the researcher controls all the conditions and directly manipulates the conditions, including the independent variable.

Front 12

confounding or extraneous variables

Back 12

Variables that have an unwanted influence on the outcome of an experiment.

Front 13

controls

Back 13

Constraints that the experimenter places on the experiment to ensure that each subject has the exact same conditions.

Front 14

random assignment

Back 14

Each subject of the sample has an equal likelihood of being chosen for the experimental group of an experiment.

Front 15

ex post facto

Back 15

Research in which we choose subjects based on a pre-existing condition.

Front 16

correlational study

Back 16

A type of research that is mainly statistically in nature. Correlational studies determine the relationship (or correlation) between two variables.

Front 17

survey

Back 17

A quasi-experimental method in which questions are asked to subjects. When designing a survey, the researcher has to be careful that the questions are not skewed or biased toward a particular answer.

Front 18

naturalistic observation

Back 18

A research method in which subjects are observed in their natural environment.

Front 19

longitudinal study

Back 19

A type of study in which one group of subjects is followed and observed (or examined, surveyed etc.) for an extended period of time (years).

Front 20

cross-sectional study

Back 20

A study in which a representative cross-section of the population is tested or surveyed at one specific time.

Front 21

cohort-sequential study

Back 21

A research method in which a cross section of the population is chosen and then each cohort is followed for a short period of time.

Front 22

personal bias

Back 22

The researcher allowing personal beliefs to affect the outcome of the study.

Front 23

expectancy bias

Back 23

The researcher allowing his or her expectations to affect the outcome of a study; or, in memory, a tendency to distort recalled events to make then fit one's expectations.

Front 24

double-blind study

Back 24

An experimental procedure in which both researchers and participants are uninformed about the nature of the independent variable being administered.

Front 25

Institutional Review Board (IRB)

Back 25

A committee at each institution where research is conducted to review every experiment for ethics and methodology.

Front 26

Institutional Animal Care and Use Committee (IACUC)

Back 26

A committee at each institution where research is conducted to review every experiment INVOLVING ANIMALS for ethics and methodology.

Front 27

ABCs of laboratory animal research

Back 27

Appropriate, Beneficial, and Caring

Front 28

frequency distribution

Back 28

A summary chart, showing how frequently each of the scores in a set of data occurs.

Front 29

histogram

Back 29

A bar graph depicting a frequency distribution. The height of the bars indicates the frequency of a group of scores.

Front 30

descriptive statistics

Back 30

Statistical procedures used to describe characteristics and responses of groups of subjects.

Front 31

mean

Back 31

The measure of central tendency most often used to describe a set of data --- calculated by adding all the scores and dividing by the number of scores.

Front 32

median

Back 32

The measure of central tendency for a distribution, represented by the score that separates the upper half of the scores in a distribution from the lower half.

Front 33

mode

Back 33

A measure of central tendency for a distribution, represented by the score that separates the upper half of the scores in a distribution from the lower half.

Front 34

range

Back 34

The simplest measure of variability, represented by the difference between the highest and the lowest values in a frequency distribution.

Front 35

standard deviation (SD)

Back 35

A measure of variability that indicates the average difference between the scores and their mean.

Front 36

correlation

Back 36

A relationship between variables, in which changes in one variable are reflected in changes in the other variable --- as in the correlation between a child's age and height.

Front 37

normal distribution

Back 37

A bell-shaped curve, describing the spread of a characteristic throughout a population.

Front 38

correlation coefficient

Back 38

A number between -1 and +1 expressing the degree of relationship between two variables.

Front 39

inferential statistics

Back 39

Statistical techniques (based on probability theory) used to assess whether the results of a study are reliable or whether they might be simply the result of chance. Inferential statistics are often used to determine whether two or more groups are essentially the same or different.

Front 40

random sample

Back 40

A sample group of subjects selected by chance (without biased selection techniques).

Front 41

representative sample

Back 41

A sample obtained in such a way that it reflects the distribution of important variables in tee larger population in which the researchers are interested --- variables as age, income level, ethnicity, and geographic distribution.

Front 42

significant difference

Back 42

Psychologists accept a difference between the groups as "real", or significant, when the probability that it might be due to an atypical sample drawn by chance is less than 5 in 100 (indicated by the notation p < .05).