Academic research has a specific vocabulary. Using research terms correctly and precisely signals competence to your reader, improves the clarity of your writing, and is directly assessed in Extended Investigation. This note covers the core concepts and terms you need to command.
In research writing, imprecise terminology leads to imprecise thinking. If you use “reliable” when you mean “valid,” or “hypothesis” when you mean “assumption,” your reader may misunderstand your argument. More importantly, you may be thinking imprecisely yourself.
KEY TAKEAWAY: Learn these terms to the point where you can use them naturally in your writing — not just define them in a glossary. They should appear throughout your report as analytical tools, not just in a “definitions” section.
| Term | Definition |
|---|---|
| Research question | The specific question the investigation aims to answer |
| Hypothesis | A testable prediction about the relationship between variables (used in experimental/quantitative research) |
| Variable | Any characteristic that can take different values |
| Independent variable | The variable manipulated by the researcher (cause) |
| Dependent variable | The variable measured as an outcome (effect) |
| Confounding variable | A variable that correlates with both independent and dependent variables, potentially distorting the relationship |
| Control group | Group not exposed to the experimental treatment; provides a baseline for comparison |
| Sample | The subset of the population from which data is collected |
| Population | The full group about which the researcher wants to draw conclusions |
| Sampling frame | The complete list of members of the population from which a sample is drawn |
| Term | Definition |
|---|---|
| Research design | The overall strategy for collecting and analysing data |
| Methodology | The theoretical framework justifying the approach; also used loosely for “methods” |
| Primary data | Data collected directly by the researcher for the investigation |
| Secondary data | Data collected by others, accessed and re-used |
| Quantitative research | Research that produces and analyses numerical data |
| Qualitative research | Research that produces and analyses non-numerical data (text, images, themes) |
| Mixed methods | Research combining quantitative and qualitative approaches |
| Longitudinal study | Data collected from the same participants over an extended period |
| Cross-sectional study | Data collected from participants at a single point in time |
| Case study | Detailed investigation of a single case (person, organisation, event) |
| Term | Definition |
|---|---|
| Validity | The degree to which an instrument or study measures what it claims to measure |
| Internal validity | Confidence that the independent variable caused the observed outcome (relevant to experiments) |
| External validity | Degree to which findings can be generalised to other contexts or populations |
| Ecological validity | Degree to which findings apply to real-world conditions |
| Reliability | Consistency of measurement — same results if repeated under same conditions |
| Operationalisation | Defining an abstract concept in measurable terms (e.g., “wellbeing” measured using the WHO-5 scale) |
EXAM TIP: “Validity” and “reliability” are frequently confused. Reliability is about consistency; validity is about accuracy. A scale that consistently shows you are 5kg too light is reliable but not valid. A mnemonic: valid = measuring the right thing; reliable = measuring it consistently.
| Term | Definition |
|---|---|
| Correlation | A statistical relationship between two variables — they vary together |
| Causation | One variable directly produces change in another |
| Statistical significance | The result is unlikely to be due to chance (p-value below threshold, typically 0.05) |
| Effect size | The magnitude of a relationship or difference, independent of sample size |
| Thematic analysis | Qualitative method for identifying, organising and reporting themes in data |
| Content analysis | Systematic categorisation of content in documents or media |
| Triangulation | Using multiple sources, methods or perspectives to cross-check findings |
| Saturation | In qualitative research, the point at which new data no longer produces new themes |
| Term | Definition |
|---|---|
| Rationale | Justification for the research question and methods chosen |
| Literature review | Synthesis of existing research relevant to the investigation |
| Abstract | Brief summary of the whole report |
| Limitations | Aspects of the methodology or evidence that reduce confidence in the findings |
| Implications | The significance or consequences of the findings |
| Further research | Suggested future investigations prompted by the findings or limitations |
APPLICATION: Create a personal glossary as you encounter new terms throughout your investigation. For each term, write the definition in your own words and include an example from your own research area. This active processing helps you use terms naturally.
COMMON MISTAKE: Using technical terms without understanding them. Phrases like “the paradigm of my methodology” or “the validity of my reliable results” signal that terms are being used for appearance rather than meaning. Use each term only when it is the precise word needed.
