Research glossary
The vocabulary of research methods and academic publishing, defined precisely and in plain English — with the free calculators and guides that put each term to work.
C
- Chi-square test
A test of association between categorical variables, comparing observed counts in a contingency table with the counts expected under independence.
- Confidence interval
A range of plausible values for a population parameter, constructed so that the procedure captures the true value a stated share of the time (usually 95%).
- Confounding variable
A third variable that influences both the presumed cause and the outcome, creating a spurious or distorted association.
- Construct validity
The degree to which a measure actually captures the concept it claims to measure.
- Correlation
A standardized measure (−1 to +1) of how strongly two variables move together. Association, not causation.
H
I
- Impact factor
A journal metric: the mean citations in a year to items the journal published in the previous two years. A journal average — not a paper’s or author’s quality score.
- Independent and dependent variables
The independent variable is what you manipulate or compare; the dependent variable is the outcome you measure to see the effect.
- Internal and external validity
Internal validity is whether the study really shows what it claims within its setting; external validity is whether the result generalizes beyond it.
L
- Likert scale
The survey format asking respondents to rate agreement on a symmetric scale (e.g. strongly disagree → strongly agree), typically with 5 or 7 points.
- Literature review
A synthesis of existing research on a topic that maps what is known, where the field disagrees, and what gap the new work fills.
M
N
- Non-parametric test
A test that makes minimal assumptions about the data’s distribution, typically by working on ranks — Mann-Whitney, Wilcoxon, Kruskal–Wallis, Spearman.
- Normal distribution
The symmetric, bell-shaped distribution that arises whenever many small independent influences add up — the default assumption behind parametric statistics.
- Null hypothesis
The default assumption a statistical test tries to discredit — usually that there is no effect, no difference, or no relationship.
O
- Open access
Publishing that makes research freely readable — gold (journal-side, often via APCs), green (self-archived copies), diamond (free for both sides).
- Operationalization
Translating an abstract concept into something concrete you can measure — defining exactly what counts as "stress", "engagement", or "success" in your study.
P
- P-value
The probability of observing data at least as extreme as yours if the null hypothesis were true. It is not the probability that the hypothesis is true.
- Peer review
The evaluation of scholarly work by independent experts before publication — the quality filter, imperfect but load-bearing, of academic publishing.
- Preprint
A manuscript shared publicly (arXiv, bioRxiv, SSRN, OSF) before — or while — undergoing journal peer review.
- Preregistration
Publicly time-stamping your hypotheses, design, and analysis plan before collecting data, so confirmatory and exploratory results stay distinguishable.
- PRISMA
The reporting standard for systematic reviews — a 27-item checklist and the flow diagram tracking records from identification to inclusion.
- Publication bias
The tendency for significant, positive results to get published while null results stay in file drawers — skewing what the literature shows.
R
- Randomized controlled trial (RCT)
An experiment in which participants are randomly assigned to intervention or control, making the groups comparable and causal inference possible.
- Regression analysis
A family of models that predict an outcome from one or more predictors, quantifying each predictor’s contribution while holding the others constant.
- Reliability
The consistency of a measure — across items (internal consistency), time (test–retest), and raters (inter-rater).
- Replication crisis
The finding, across several fields, that many published results fail to reproduce when independently repeated — and the reform movement it triggered.
S
- Sample size
The number of participants or units in a study — determined by power analysis (quantitative) or saturation (qualitative), not convention.
- Sampling bias
Systematic error introduced when the people (or units) in your sample differ from the population you want to describe.
- Saturation
The point in qualitative data collection where additional interviews or observations stop yielding new codes, themes, or insights.
- Standard deviation
A measure of how spread out values are around their mean, in the same units as the data.
- Standard error
The standard deviation of an estimate across hypothetical repeated samples — how precisely you know a mean, proportion, or coefficient.
- Statistical power
The probability that a study will detect an effect of a given size if it really exists — conventionally targeted at 80%.
- Statistical significance
The convention of treating a result as unlikely to be pure chance when its p-value falls below a preset threshold, usually 0.05.
- Systematic review
A literature review conducted as a documented method: registered question, comprehensive search, explicit criteria, and reproducible screening.
T
- T-test
A test of whether two means differ: one sample against a known value, two independent groups, or paired measurements.
- Thematic analysis
A widely used qualitative method for identifying and interpreting patterns (themes) across a dataset, canonically via Braun and Clarke’s six phases.
- Triangulation
Strengthening a conclusion by approaching it through multiple methods, data sources, researchers, or theories.
- Type I and Type II errors
A Type I error is a false positive (rejecting a true null); a Type II error is a false negative (missing a real effect).
Put the vocabulary to work
Kahubi runs the tests, screens the papers, and writes the methods — with the definitions applied correctly. Free plan included.