Lecture Notes: Psychology Research Methods and Statistics - Vocabulary

Vocabulary flashcards covering key research methods, statistics, and ethics terms from the lecture notes.

Cultural norms

Shared expectations about appropriate behavior within a culture or group.

Median

The middle value of a data set when arranged in order; 50th percentile.

Confirmation bias

Tendency to seek, interpret, and remember information that confirms preconceptions.

Mode

The most frequently occurring value in a data set.

Hindsight bias

The tendency to see events as having been predictable after they occur.

Range

Difference between the highest and lowest scores in a distribution.

Overconfidence

Excessive belief in one’s own accuracy or knowledge.

Normal curve

Also called the normal distribution; bell-shaped, symmetric distribution where mean=median=mode.

Independent variables

Variables deliberately manipulated to observe their effect on the dependent variable.

Positive skew

Distribution with a long tail on the right; most scores are low, with few high scores.

Confounding variables

Variables other than the IV that may affect the DV, creating false associations.

Negative skew

Distribution with a long tail on the left; most scores are high.

Dependent variables

Variables measured to assess the effect of the IV; the outcome.

Random assignment

Randomly assigning participants to conditions to reduce preexisting differences.

Case study

In-depth examination of a single person, group, or event.

Correlation

Statistical relationship between two variables; does not imply causation.

Positive Correlation

As one variable increases, the other tends to increase.

Negative Correlation

As one variable increases, the other tends to decrease.

Meta-analysis

Statistical method that combines results from multiple studies to identify overall effects.

Naturalistic observation

Observing behavior in a natural environment without interference.

Hypothesis

A testable prediction about a relationship between variables.

Operational definitions

Precise, measurable definitions of variables used in a study.

Replication

Repeating a study to verify whether findings hold under similar conditions.

Measures of Central Tendency

Statistics that describe the center of a data set (mean, median, mode).

Measures of Variation

Statistics that describe the spread of a data set (range, variance, standard deviation).

Percentile rank

Percentage of scores at or below a given score in a distribution.

Mean

Arithmetic average of a set of numbers.

Bimodal distribution

Distribution with two distinct peaks or modes.

Standard deviation

Average distance of scores from the mean; a measure of spread.

Regression toward the mean

Extreme scores tend to move toward the average on subsequent measurements.

Sample

A subset of a population used in a study.

Population

The entire group of individuals of interest.

Representative sample

A sample that mirrors the characteristics of the population.

Random sampling

Selecting participants so each member of the population has an equal chance.

Generalizing

Extending findings from a sample to the broader population.

Experimental group

Group that receives the treatment or manipulation.

Control group

Group that does not receive the treatment; serves as a baseline.

Placebo

An inert substance or condition used to control for expectancy effects.

Placebo effect

Improvement due to participants’ expectations rather than the treatment.

Single-blind study

Participants do not know their condition, but researchers do.

Double-blind study

Neither participants nor researchers know who is in which condition.

Experimenter bias

Researchers’ expectations influence data collection or interpretation.

Qualitative research

Research that gathers non-numerical data to understand meanings and experiences.

Structured interviews

Interviews with a fixed set of questions to standardize responses.

Quantitative research

Research that collects numerical data and analyzes statistically.

Likert scales

Rating scales (e.g., 1–5) used to measure attitudes or opinions.

Peer review

Evaluation of research by experts in the field before publication.

Scatterplot

Graph showing the relationship between two variables as data points.

Correlation coefficient

Numerical index (r) describing the strength and direction of a linear relationship.

Effect sizes

Quantitative measure of the magnitude of a treatment or relationship.

Statistical significance

Result unlikely to occur by chance, typically p < .05, given a hypothesis test.

Third variable problem (in correlation)

A third variable may cause the observed correlation between two variables.

Institutional review

Ethical review process by an Institutional Review Board to protect participants.

Informed consent

Participants’ voluntary agreement to participate after being informed of risks.

Informed assent

Agreement by a minor or cognitively incapable participant, with parental consent.

Protection from harm

Ethical obligation to minimize physical and psychological risk to participants.

Confidentiality

Keeping participants’ data private and secure.

Deception

Misleading participants or withholding information; allowed only when justified.

Debriefing

Post-study explanation of purpose and methods; reveal deception if used.