Learn: Psychology Perspectives, Research Methods, and Data Analysis in Experimental Design

Biological / Neuroscience Perspective

Explains behavior and mental processes through biological structures, genetics, and neurochemistry.

Evolutionary Perspective

Explains behavior and mental processes using principles of natural selection and survival adaptability.

Psychodynamic / Psychoanalytic Perspective

Focuses on the influence of unconscious drives, childhood experiences, and hidden conflict.

Behavioral Perspective

Focuses on observable behaviors learned through rewards, punishments, and environmental conditioning.

Humanistic Perspective

Emphasizes human potential, free will, personal growth, and self-actualization.

Cognitive Perspective

Focuses on internal mental processes including memory, perception, problem-solving, and decision-making.

Social-Cultural Perspective

Examines how social situations, cultural norms, and environment shape thinking and behavior.

Biopsychosocial Perspective

Integrates biological, psychological, and social-cultural factors to explain behavior and health.

Confirmation Bias

The tendency to search for, interpret, and recall information that confirms preexisting beliefs while ignoring opposing evidence.

Hindsight Bias

The tendency to believe, after an outcome occurs, that one foresaw or 'knew it all along'.

Overconfidence

The tendency to overestimate the accuracy of one's own knowledge, judgments, or abilities.

Experiment

A research method where variables are manipulated under controlled conditions to determine cause-and-effect relationships.

Independent Variable (IV)

The variable that is manipulated or altered by the experimenter to test its effect.

Dependent Variable (DV)

The variable being measured that changes in response to manipulations of the independent variable.

Random Assignment

Placing participants into experimental or control groups by chance to minimize pre-existing group differences.

Experimental Group

The group in an experiment that receives the treatment or independent variable being tested.

Control Group

The baseline group in an experiment that does not receive the treatment, used for comparison.

Placebo

An inactive substance or fake treatment given to a control group to measure expectations versus actual physiological effects.

Non-experimental Research

Research methods that observe and measure variables as they naturally occur without manipulation.

Correlation

A statistical measure expressing the extent to which two variables vary together and predict each other.

Directionality Problem

The uncertainty in correlation regarding whether variable A causes variable B or variable B causes variable A.

Third-Variable Problem

An unmeasured variable that causes changes in both observed variables, creating a false correlational link.

Correlation Does Not Equal Causation

The principle that a relationship between two variables does not guarantee one causes the other.

Case Study

An in-depth observational investigation of a single individual or small group.

Meta-Analysis

A statistical technique that combines and analyzes data from multiple independent studies on the same topic.

Naturalistic Observation

Recording behavior in its natural environment without researcher intervention or manipulation.

Hypothesis

A testable, specific prediction derived from a theory about the relationship between variables.

Operational Definitions

Precise, measurable descriptions of how variables are defined and quantified in a study.

Confounding Variable vs. Third Variable

A confounding variable directly interferes with the independent variable in an experiment, while a third variable accounts for the correlation between two variables in non-experimental research.

Sample

A representative subset of individuals selected from a larger population for a study.

Population

The entire group of interest from which a sample is drawn and to which study results apply.

Representative Sample

A sample whose demographic characteristics closely resemble those of the target population.

Random Sample

A sampling process where every individual in the target population has an equal probability of selection.

Convenience Sampling

Selecting participants who are easiest to reach or recruit, which may compromise representativeness.

Sampling Bias

Systematic errors in selecting a sample that lead to an unrepresentative group.

Sample Size

The total number of participants or observations included in a research study.

Generalizability

The extent to which experimental results from a sample can be applied to the broader target population.

Single-Blind vs. Double-Blind Study

In a single-blind study, participants do not know their group assignment; in a double-blind study, neither participants nor experimenters know group assignments.

Measurement Tools

Instruments or tests used to collect data, such as surveys, physiological tools, or scales.

Qualitative vs. Quantitative Data

Qualitative data consists of descriptive text and observations, while quantitative data consists of numerical values and statistics.

Peer Review and Replication

Peer review involves evaluation by independent experts, while replication is repeating a study to confirm original findings.

Institutional Review Board (IRB)

An administrative ethics committee that reviews research designs to protect participant rights and safety.

Informed Consent

Providing potential participants sufficient study details so they can voluntarily agree to join.

Protect From Harm

The ethical requirement that researchers minimize physical and emotional discomfort or risk for participants.

Confidentiality

The ethical standard requiring that participants' personal identities and individual responses remain private.

Deception and Confederates

Deception is withholding true study aims when necessary, while confederates are actors posing as real participants.

Debriefing

Explaining the true purpose, hypotheses, and any used deceptions to participants after a study concludes.

Human and Animal Ethics

Standards ensuring safety and consent for human participants, and humane treatment, housing, and care for animal subjects.

Identify Variables in Charts/Graphs

Locating independent variables on the horizontal (x) axis and dependent variables on the vertical (y) axis.

Central Tendency

Statistical measures representing the central or middle point of a distribution (mean, median, mode).

Mean

The arithmetic average calculated by dividing the sum of all scores by the total number of scores.

Median

The middle score in an ordered set of numbers, dividing the top half from the bottom half.

Mode

The most frequently occurring value or score in a data set.

Range

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

Normal Curve

A symmetrical, bell-shaped distribution where scores cluster around the mean and taper toward extremes.

Skew

An asymmetrical distribution of scores where data tails off to either the positive (right) or negative (left) side.

Bimodal Distribution

A score distribution that features two distinct peaks or modes.

Distribution of Scores

The pattern or frequency of scores across a measured scale.

Standard Deviation

A statistical measure indicating how much scores vary or spread out around the mean score.

Scatterplot

A graph of plotted points representing the relationship between two quantitative variables.

Correlation Coefficient

A statistical index ($r$) ranging from $-1.00$ to $+1.00$ that measures the strength and direction of a linear relationship.

Interpretation of Results

Assessing empirical data to draw conclusions regarding hypotheses and real-world application.

Effect Size

A quantitative measure of the magnitude or strength of a phenomenon or experimental treatment.

Statistical Significance

A statistical determination ($p < 0.05$) indicating that results are unlikely to have occurred purely by chance.