AP Psych - Vocab Unit 0

Sample

smaller group of individuals that are selected from a larger population in order to represent and generalize findings about the entire population

Population

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

Standard Deviation

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

percentile rank

the percentage of scores that are lower than a given score.

Hypothesis

a testable prediction, often implied by a theory.

Falsifiable

the possibility that an idea, hypothesis, or theory can be disproven by observation or experiment

Operational Definition

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.

Independent Variable

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

Dependent Variable

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

Confounding Variable

in an experiment, a factor other than the factor being studied that might influence a study's results.

Sampling Bias

a flawed sampling process that produces an unrepresentative sample.

Representative sample

A subset of a statistical population that accurately reflects the members of the entire population. This sample should be an unbiased indication of what the population is like.

Random Sampling

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

Convenience Sampling

Using a group of participants not randomly selected from the target population, but invited to participate because they are easily contactable

Generalizability

results of your study can be applied to different types of people

Experimental Group

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

Control Group

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.

Placebo

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.

Single-blind

an experimental procedure in which the research participants are ignorant (blind) about whether they have received the treatment or a placebo.

Double-blind

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.

Social Desirability Bias

bias from people's responding in ways they presume a researcher expects or wishes.

Qualitative

a research method that relies on in-depth, narrative data are not translated into numbers. (Ex: structured interviews)

Quantitative

a research method that relies on quantifiable, numerical data (Likert scales)

peer reviewers

scientific experts who evaluate a research article's theory, originality, and accuracy.

replication

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

Cultural Norms

shared expectations and rules that guide behavior within a specific culture or society. They shape our beliefs, values, and behaviors by providing guidelines for what is considered acceptable or appropriate in different social contexts.

Confirmation bias

a tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence.

Hindsight bias

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

Overconfidence

the tendency to be more confident than correct — to overestimate the accuracy of our beliefs and judgments.

experimental

Ex: random assignment:
assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups

case study

a non-experimental technique in which one individual or group is studied in depth in the hope of revealing universal principles.

correlation

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other. (Non experimental)

Meta Analysis

a statistical procedure for analyzing the results of multiple studies to reach an overall conclusion.

variable

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

Directionality problem(Correlation)

when two variables are correlated, but it's not clear which variable is causing the other to change

Third Variable Problem (Correlation)

A type of undiscovered variable in which a third variable leads to a mistaken causal relationship between two others.

Survey Technique/Method

Technique where questions are asked to subjects who report their own answers. It's like taking a poll to gather information about people's opinions or behaviors

self-report bias

bias when people report their behavior inaccurately.

Institutional Review

a committee that reviews, approves, and monitors biomedical and behavioral research conducted on humans

informed consent

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

informed assent

giving potential participants(Minors) enough information about a study to enable them to choose whether they wish to participate.

Protection from harm

an ethical principle in psychology that ensures participants are not subjected to physical or psychological harm during a study.

Confidentiality

the experimenters will not release any information about subjects without their consent

debriefing

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

Deception

when a researcher intentionally misleads or withholds information from research participants

Research Confederates

a person who is recruited by an experimenter to participate in an experiment, but is not a true participant and is not being observed by the researcher

mean

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

Median

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

Mode

the most frequently occurring score(s) in a distribution.

Range

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

Normal Curve (With % of distributions across the curve)

a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean

Variation

a measure of how spread out a data set is and how different the points are from each other

Skewness

the degree to which a set of scores, measurements, or other numbers are asymmetrically distributed around a central point

Bimodal distribution

a data set with two modes, or two distinct clusters of data

regression toward the mean

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

scatterplot

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).

correlation coefficient

a statistical index of the relationship between two things (from −1.00 to +1.00).

Effect size

the strength of the relationship between two variables. The larger the correlation, the more one variable can be explained by the other.

statistical significance

a statistical statement of how likely it is that a result (such as a difference between samples) occurred by chance, assuming there is no difference between the populations being studied.