How to Write a Research Introduction and Rationale: Structure, Example and Phrasing

How to write the introduction of a seminar paper or thesis and what a research rationale is - the funnel structure, theoretical vs practical rationale, the research question, example paragraphs and common mistakes.

Part of the series: Seminar Paper Structure: Every Chapter, What Goes In It and How Long It Should Be

"Write an introduction" and "the rationale is missing" are the two most common comments on first drafts. The introduction is the first page the marker reads, and the rationale answers the question they're asking themselves: why was this study needed? This guide shows what goes in each, with example paragraphs.

Introduction, rationale and literature review - the difference

At some institutions all three are one chapter ("Introduction") built as a funnel; at others the rationale is a separate section before the hypotheses. Check your course guidelines - the content is the same either way.

The introduction: a four-step funnel

1. Topic and importance - a sentence or two: what the phenomenon is and why it matters (a figure, a consequence, the local context).
2. The key concepts - which variables the paper deals with, in a sentence.
3. What isn't known - a hint of the gap the review will develop.
4. What the paper does - the aim in one sentence, and how the chapter is organised.

Example introduction paragraph

Admission tests such as the psychometric entrance exam and graduate admission tests shape the paths of thousands of students each year, so factors unrelated to ability may still affect their futures. One of the most studied is test anxiety, which is linked to lower performance across a wide range of tests (von der Embse et al., 2018). Less is known, however, about its effect on time-limited quantitative sections. The present paper examines the relationship between test anxiety and scores on the quantitative and verbal sections of a graduate admission test.

Four sentences, four steps. No "since the dawn of time", no dictionary definitions.

The rationale: why this study is needed

A good rationale answers three questions, in this order:

1. What is known? One or two sentences summarising what the review showed.
2. What is missing? The gap - an unstudied population or setting, contradictory findings, or an unclear mechanism.
3. Why does it matter? The contribution - theoretical (what we learn about the theory) and/or practical (what can be done with the answer).

Example rationale

Many studies show a negative link between test anxiety and achievement, and attentional control theory predicts the impairment will be stronger in tasks that load working memory (Eysenck et al., 2007). Most studies, however, used school students and classroom tests, and few compared quantitative and verbal sections of the same test. That comparison tests a direct prediction of the theory (theoretical contribution) and, if the impairment is concentrated in the quantitative section, would allow anxiety-reduction interventions to target it (practical contribution).

From rationale to research question and hypotheses

The rationale should lead directly to the question. If the gap is "the difference between sections hasn't been tested", the question is "does the relationship differ between sections?" and the hypothesis "the relationship will be stronger in the quantitative section". A simple test: if you could swap the rationale without changing the hypotheses, the rationale isn't doing its job. To see the whole funnel from definitions to hypotheses, see the literature review example.

Phrases that help

• For the gap: "However, few studies have examined...", "Findings on this are inconsistent...", "It is not yet known whether..."
• For the contribution: "The findings may contribute to understanding...", "In practical terms, ..."
• For the aim: "The aim of the present study is to examine..."

Common mistakes

• "The topic interests me" as a rationale - personal interest isn't a research justification.
• "No such study has been done in Israel" without explaining why the local context would change anything.
• A gap that doesn't come from the review - it appears out of nowhere.
• An introduction that starts reviewing studies - that's the review's job.
• An inflated contribution - "the study will transform the education system". Modest and precise is better.

FAQ

What's the difference between an introduction and a rationale? The introduction presents the topic and the paper's aim; the rationale explains why the study is needed - the gap and the contribution. In many papers the rationale is the last part of the introduction, before the hypotheses.

How long is a rationale? Half a page to a page in a seminar paper; one to two pages in a thesis.

When do I write the introduction? A draft at the start to steer the work, and the final version at the end, when you know exactly what the paper did. See the order to write in.

Do I need both a theoretical and a practical rationale? Not always; at least one, stated clearly. Both together are stronger.

My marker wrote "rationale missing" and I'm not sure what to fix. Send us the draft - we'll point to exactly where the link between the gap and the hypotheses breaks.

Sources for the example

• Eysenck, M. W., Derakshan, N., Santos, R., & Calvo, M. G. (2007). Anxiety and cognitive performance: Attentional control theory. Emotion, 7(2), 336–353.
• von der Embse, N., Jester, D., Roy, D., & Post, J. (2018). Test anxiety effects, predictors, and correlates: A 30-year meta-analytic review. Journal of Affective Disorders, 227, 483–493.

Last updated: 2026-10-01