Methods, Ethics, and Data Collection: every key term you need (+ practice quiz)

More AP Research guides

• Literature Review and the Scholarly Conversation
• Analysis, Findings, and Academic Writing
• The Academic Paper and Presentation Defense

Methodology

The overall logic and justification for how a study generates knowledge, including why the chosen design fits the research question.

Method

The specific procedures used to collect and analyze data, described precisely enough that another researcher could repeat them.

Quantitative Research

Inquiry using numerical measurement and statistical analysis to test relationships across many cases.

Qualitative Research

Inquiry using non-numerical data such as interviews, texts, or observations to interpret meaning in depth for fewer cases.

Mixed Methods

A design combining quantitative and qualitative strands so each compensates for the other's blind spots.

Experiment

A design in which the researcher manipulates an independent variable and randomly assigns participants to conditions to support causal claims.

Quasi-Experiment

A design with a manipulated variable but without random assignment, often using intact groups such as existing class sections.

Correlational Design

A design measuring how strongly two variables move together without manipulating either, so it cannot establish causation.

Control Group

The comparison group that does not receive the treatment, providing a baseline against which the treatment group is judged.

Random Assignment

Allocating participants to conditions by chance so preexisting differences are spread evenly across groups.

Random Sampling

Selecting participants from a population by chance so the sample is likely to represent it, which supports generalization.

Convenience Sample

A sample of whoever is easily available, common in student research and a major limitation on generalizability.

Purposive Sampling

Deliberately selecting participants who have specific experience or characteristics relevant to the question, standard in qualitative work.

Snowball Sampling

Recruiting additional participants through referrals from initial ones, useful for hard-to-reach populations.

Stratified Sampling

Dividing a population into subgroups and sampling within each so every subgroup is represented in known proportion.

Sample Size

The number of cases studied, which affects precision and the ability to detect real differences.

Survey Instrument

A structured set of questions administered identically to all respondents to gather comparable self-report data.

Likert Scale

An ordered agreement scale, typically 1 to 5 or 1 to 7, used to quantify attitudes on a survey.

Leading Question

A question whose wording pushes respondents toward a particular answer, a threat to instrument validity.

Semi-Structured Interview

An interview with a prepared question guide plus freedom to follow up, balancing comparability with depth.

Content Analysis

Systematically coding texts, images, or media into categories so patterns can be counted and compared.

Coding Scheme

The defined set of categories and decision rules used to classify qualitative data consistently.

Intercoder Reliability

The degree to which two independent coders assign the same codes to the same material, evidencing that the scheme is not idiosyncratic.

Ethnography

Extended immersive fieldwork in a community to describe its practices and meanings from participants' perspectives.

Case Study

An in-depth examination of a single bounded instance such as one school, firm, or patient, valued for depth rather than breadth.

Validity

Whether an instrument or design actually measures what it claims to measure and supports the inferences drawn.

Internal Validity

Confidence that the treatment, rather than a confound, produced the observed change within the study.

External Validity

The extent to which findings apply beyond the specific sample, setting, and time studied.

Reliability

The consistency of a measure across repetitions, raters, or items; a reliable measure yields stable results.

Triangulation

Using multiple data sources, methods, or investigators to converge on a finding and reduce reliance on any one weak measure.

Pilot Study

A small trial run of the instrument or procedure used to catch confusing items and logistical problems before full collection.

Informed Consent

A participant's voluntary agreement to take part after being told the purpose, procedures, risks, and right to withdraw.

Assent and Parental Permission

For minors, the participant's own agreement plus a guardian's written permission, both normally required.

Institutional Review Board (IRB)

A committee that reviews research with human subjects for ethical acceptability; AP Research uses an analogous school-level review.

Anonymity

A condition in which the researcher cannot link responses to identities at all, the strongest privacy protection.

Confidentiality

A promise that identities are known to the researcher but will not be disclosed or published.

Vulnerable Population

Groups such as minors, prisoners, or patients whose capacity to consent freely is limited, requiring extra safeguards.

Debriefing

Explaining a study's full purpose to participants afterward, especially necessary when any information was withheld during the study.

Data Fabrication and Falsification

Inventing data or altering results; both are serious research misconduct that invalidate a study.

Replicability of Method

Writing the method section in enough procedural detail that another researcher could carry out the same study.