AP Psych Study Guide

Experimental psychology

Study of behavior and thinking using the experimental method

Psychology

Science of behavior and mental processes

Hindsight bias

I-knew-it-all-along phenomenon

Critical thinking

Thinking that does not blindly accept arguments and conclusions

Hypothesis

Testable prediction implied by a theory

Operational definition

Carefully worded statement of the exact procedures

Replication

Repeating the essence of a research study

Case study

Studying one person in depth to reveal universal principles

Survey

Technique for finding the self-reported attitudes or behaviors of a particular group

Population

All the cases in a group being studied

Random sample

A sample that fairly represents a population

Naturalistic observation

Observing and recording behavior in natural situations

Correlation

Measure of the extent to which two factors vary together

Correlation coefficient

A statistical index of the relationship between two things from -1 to +1

Scatterplot

Cluster of dots on a graph

Experiment

Research method where one or more factors are manipulated to observe effect on behavior

Random assignment

Assigning participants to experimental and control groups by chance

Double blind procedure

When both the participants and the researchers don’t know who has the treatment and who has the placebo

Placebo effect

Experimental results caused by expectations alone

Experimental group

Group that is exposed to the treatment

Control group

The group that is not exposed to the treatment

Independent variable

The experimental factor that is manipulated

Confounding variable

Factor other than the independent variable that might produce an effect in an experiment

Dependent variable

The variable that might change in response to manipulations; the outcome factor

Mode

The most frequently occurring scores in a distribution

Mean

Average of a distribution

Median

The middle score in a distribution

Range

The difference between the highest and lowest scores

Standard deviation

A computed measure of how much scores vary around the mean

Normal curve

Bell shaped curve that describes the distribution of data

Informed consent

Participants be told enough to enable them to choose whether they wish to participate

Debriefing

Post experiment explanation of a study

Sampling bias

Flawed sampling process that produces an unrepresentative sample

Regression toward the mean

Tendency for extreme or unusual scores to fall back toward average

Skewed distribution

A representation of scores that lack symmetry

Statistical significance

How likely it is that an obtained result occurred by chance

Bimodal distribution

Frequency distribution having two different values that are heavily populated with cases

Confederate

Someone who poses as a participant but whose behavior is rehearsed

Confidentiality

Requires researchers to limit the disclosure of the participants identities

Confirmation bias

Searching for information that supports our preconceptions and ignoring contradictory evidence

Convenience sampling

Process for selecting a sample of individuals or cases that is governed by chance or ready availability

Cultural norm

Societal value, rule, or standard that delineates an accepted and appropriate behavior within a culture

Deception

Any distortion of or withholding of fact with the purpose of misleading

Descriptive statistics

Techniques used to summarize and describe the characteristics or properties of a data set

Directionality problem

Situation when two variables are related but it is unknown which is the cause and which is the effect

Ethical guidelines

Rules of acceptable conduct that members of a given profession are expected to follow

Experimenter bias

When researchers expectations or preferences about the outcome influence the results

Falsifiable

For a hypothesis or theory to be considered scientific, it must be possible to conceive of evidence that would prove it false

Generalizability

Degree to which a study’s findings based on a sample apply to the entire population

Inferential statistics

Techniques used to make inferences about a population based on data

Informed assent

Agreement of someone not able to give legal consent to participate in the activity

Institutional review board

Committee at each college where research is conducted to review every experiment for ethics

Meta analysis

A procedure for statistically combining the results of many different research studies

Negative correlation

Relationship between two variables which the value of one variable increases as the other decreases

Negative skew

Degree to which a set of scores are asymmetrically distributed with majority towards the high end

Non experimental

Research in which the investigator cannot randomly assign units or participants to conditions or have control

Participant bias

Tendency for research participants to respond in a certain way because they know they are being observed

Peer review

Evaluation of scientific, academic, or professional work by others in the same field

Placebo effect

Experimental results caused by expectations alone

Placebo group

Any group that receives any medical or psychological intervention believed to be inert

Population

All the cases in a group being studied

Positive correlation

Relationship between two variables in which both rise and fall together

Positive skew

Data with measurements towards the low end and few on the high end

Protection from harm

Steps to avoid and minimize adverse effects

Qualitative research methods

Research that focuses on analyzing observations

Quantitative research methods

Research that focuses on analyzing numerical data

Random assignment

Assigning participants to experimental and control groups by chance

Regression toward the mean

Tendency for extreme or unusual scores to fall back toward the average

Reliability

Ability of a test to yield very similar scores for the same individual over repeated tastings

Replication

Repeating the essence of a study to see if the findings extend to other circumstances

Representative sample

Selection of study units from a larger group in an unbiased way

Sample

Small proportion of people who are chosen in a study

Self report bias

Distortions in responses to surveys due to memory recall or misunderstandings

Single blind study

Participants don’t know whether they are in the experimental or control group

Skewed distribution

Distribution of data in which the scores cluster near one end

Social desirability bias

Tendency to give socially approved answers to questions about oneself

Survey

Technique for finding the reported behaviors of a particular group

Third variable problem

Undiscovered causative variable

Validity

Ability of a test to measure what it is intended to measure

Variation

Square of the standard deviation

Wording effects

When a specific word used in a question affects how respondents answer the question

Effect size

Any of various measures of the meaningfulness of a relationship between two variables