How to Write a Research Paper Introduction (With 3 Annotated Examples)
Dr. Rajni Garg
Executive Lead, Research & Content Strategy
8 min read
To write a research paper introduction, take the reader from your topic, to what is still unknown about it, to the question your paper answers. For example: “Writing groups are often recommended to doctoral students, but few studies have measured whether they change how much students write. This study compares PhD students who did and did not join a weekly group.”
This guide shows how to write an introduction for a research paper: the three moves behind it, five steps for drafting one, three annotated examples and the mistakes to avoid. Still planning the full paper? Read how to write a research paper.
TL;DR
An introduction moves from your topic, to what is known, to the gap, to your question.
Swales’ CARS model names three moves: establishing a territory, establishing a niche and occupying the niche.
End with your aim, question or hypothesis and a short note on what the paper does.
Keep sweeping opening lines, long literature reviews and detailed results out of it.
What does a research paper introduction do?
An introduction tells the reader what your topic is, what is already known, what is missing and how your paper deals with it. It moves from the topic to the gap to your question, so that by the last paragraph your research question feels like the obvious next step.
Think of it as a funnel. You start with a claim most people in your field would accept, narrow to the studies closest to yours, point to what they have not done, and end on your study.
The three moves: Swales’ CARS model
One of the most widely taught descriptions of how introductions work comes from the linguist John Swales. In Swales (1990), Genre Analysis: English in Academic and Research Settings (Cambridge University Press), he set out the Create a Research Space, or CARS, model, based on how published research article introductions are built.
The model has three moves, each made up of smaller steps (the UMass Amherst Writing Center lists them all):
Move 1: establishing a territory. Show that the topic matters (claiming centrality), make general statements about it, and review previous research.
Move 2: establishing a niche. Show where that research falls short, usually by indicating a gap, but also by counter-claiming, raising a question or continuing a tradition.
Move 3: occupying the niche. Say what your study does about it by outlining its purposes or announcing the present research. Some papers also announce the principal findings and indicate how the article is structured.
The moves are not paragraphs. A short introduction can make all three in one paragraph, and a long one may go through Moves 1 and 2 more than once before it reaches Move 3.
How to write a research paper introduction in 5 steps
Each step maps onto a CARS move. Steps 1 and 2 establish the territory, step 3 establishes the niche, and steps 4 and 5 occupy it.
Set the context. Open with one or two sentences on the area you are working in and why it matters. Start one level above your topic, not five: “Doctoral students are expected to publish before they graduate” does more work than “Writing is important in academia.”
Say what is known. Summarize the research your study builds on, with citations. Group studies by what they found rather than giving one study per sentence.
Name the gap. Say exactly what those studies have not done: a group not studied, a method not tried, results that conflict, or a question nobody has asked. Signal the turn with “however,” “yet” or “little is known about.”
State your aim or question. In one sentence, say what this paper does about the gap. Use a research question, an aim or a hypothesis, and check that it matches your methods.
Say what the paper does. Briefly name your design, data or setting. Some fields also expect a one-line preview of the main finding or of how the paper is organized, so check recent articles in your target journal.
If you are unsure where the gap is, the AI research gap finder suggests unexplored areas and contradictions for a research area you enter. Treat its suggestions as leads, then confirm each one in the literature.
Once you have your purpose and notes, the AnswerThis research introduction generator drafts two or three opening paragraphs from what you give it. Then add your sources and the gap from your own reading. You get 3 free runs without an account.
Research paper introduction examples, annotated
These examples are invented for teaching, so the studies are not real. Each sentence is tagged with its move, and [citation] marks where a real paper would cite earlier research.
1. Empirical study introduction
Study: Weekly writing groups and time to first manuscript submission among doctoral students
Doctoral students are expected to publish before they graduate, and many struggle to write regularly alongside lab work, teaching and coursework [citation]. (Move 1: claiming centrality) Writing groups, in which students meet each week to write side by side and set goals, are now a common form of support [citation]. (Move 1: reviewing previous research) However, most evidence for these groups comes from participants’ own accounts, and few studies have compared students who join with similar students who do not. (Move 2: indicating a gap) This study followed 180 first- and second-year PhD students in four departments at one university for one academic year. (Move 3: announcing present research) It asks whether joining a writing group is linked to more weekly writing hours and to submitting a first manuscript within twelve months. (Move 3: outlining purposes)
What to notice: Move 1 narrows from doctoral writing to writing groups, the gap is specific enough for the design to answer, and the results are not mentioned. Our guide to the research paper conclusion annotates how this same paper ends.
2. Qualitative study introduction
Study: How smallholder farmers decide whether to plant drought-tolerant maize
Drought-tolerant crop varieties are a key part of efforts to help farmers cope with drier growing seasons [citation]. (Move 1: claiming centrality) Survey studies have linked adoption to farm size, access to credit and contact with extension workers [citation]. (Move 1: reviewing previous research) These studies show who adopts new seed, but they say little about how farmers themselves weigh the decision, or what risks they see in switching. (Move 2: indicating a gap) This study draws on interviews with 30 farmers in two districts. (Move 3: announcing present research) It asks what information farmers trust when choosing seed, and what leads them to try a new variety or turn it down. (Move 3: outlining purposes)
What to notice: the gap is about understanding a decision, not measuring it, which suits a qualitative design. There is no hypothesis, just an open question.
3. Review or essay introduction
Review: A scoping review of how screen time is measured in children under five
Screen time in early childhood concerns parents, health services and researchers alike [citation]. (Move 1: claiming centrality) Studies have linked it to children’s sleep, language and physical activity [citation]. (Move 1: reviewing previous research) Yet these studies measure screen time in very different ways, from a single question for parents to device logs, which makes their results hard to compare. (Move 2: indicating a gap) This scoping review maps the measures used in studies of children under five published since 2010. (Move 3: announcing present research) It then proposes a short list of details every future study should report. (Move 3: outlining purposes)
What to notice: in a review, the gap is often a problem with the literature itself, such as findings that cannot be compared. In an argumentative essay, Move 3 is your thesis statement.
Introduction vs abstract vs background
All three set up the study, which is why they get mixed up. Each does a different job.
Section | What it does | Includes your results? | Where it goes |
|---|---|---|---|
Abstract | Summarizes the whole paper, from the problem to the main findings | Yes, the main ones | Before the main text, and it must make sense on its own |
Introduction | Moves from topic to gap to your question | No, or a one-line preview in some fields | The first section of the main text |
Background | Gives fuller context, such as history, setting, policy or key terms | No | Often its own section or chapter in a thesis or proposal |
One caveat: in a thesis, the background is often longer than the introduction, so the introduction can point to it rather than repeat it. In some journals, such as those in the BMC series, “Background” is simply the heading for the opening section, so the CARS moves apply there too.
Common mistakes in research paper introductions
An opening that is too broad. “Since the beginning of time” or “In today’s world” tells the reader nothing. Start with a claim specific to your field that you could support with a citation.
No gap. Reviewing ten studies and then announcing your aim leaves the reader to guess why the study is needed. Say what is missing in a sentence of its own. “Nobody has studied this here” counts only if there is a reason to expect different results.
Results in the introduction. Swales’ model allows a brief announcement of principal findings, and some journals expect one. Numbers, test results and tables still belong in the results section.
A question that does not match the gap. If the gap is about why something happens, measuring how often it happens will not fill it.
FAQs
How long should a research paper introduction be?
There is no fixed length. In a journal article it is often three to six paragraphs, and in a thesis it can run to several pages. Your target journal’s recent issues are the best guide.
Should I write the introduction first or last?
Both. Draft a rough version early so your question is clear, then rewrite it once the results and discussion are done, so it sets up the paper you actually wrote.
Where does the hypothesis go in an introduction?
Usually near the end, as part of Move 3, right after you name the gap. Qualitative studies usually state an aim or an open question instead.
Can I use “I” or “we” in a research paper introduction?
Usually, yes. APA Style recommends first person for describing your own work, with “I” for a single author and “we” for coauthors. Some journals prefer other conventions, so check their guidelines.
Do I still need a separate literature review section?
It depends on your field and format. Many journal articles fold the literature into the introduction, while theses and some social science articles have a separate review. If you have one, keep the introduction to the studies that set up your gap.
When your gap and question are settled, try the research introduction generator for a first draft of your opening paragraphs, then add your own sources and check every claim.
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