Research & PolicyFree tool
Research Paper Introduction From Your Notes
A cited introduction built from your own notes and sources: what's known, the gap they leave, and the question your paper answers.
Free to start · Opens in your River workspace, ready to edit and share
How to write a research paper introduction
A research paper introduction tells readers what is known about a topic, what is missing, and how your paper fills that gap, ending with its question, hypothesis or thesis. John Swales, who analyzed how journal articles open, called these three moves: establish the territory, establish a niche, occupy the niche. A good introduction cites only the studies it builds on, names a gap readers can check, and promises no more than the paper delivers.
If you get one thing right, make it the gap. In PLOS Computational Biology, Brett Mensh and Konrad Kording note that experienced readers can judge a paper's potential importance by how much its claimed gap matters1. Everything before the gap should lead to it, and everything after should answer it.
The three moves of a research paper introduction
Swales's model is called Creating a Research Space, or CARS. USC Libraries' guide to social sciences research papers sets out its three moves2 and the steps under each, and suggests using them as a template.
The three moves, in order
| Move | What it does | A sentence that does it |
|---|---|---|
| Establish the territory | Shows why the topic matters and what key studies have found | "Two studies have measured how four-day school weeks affect test scores (Author A, 2019; Author B, 2021)." |
| Establish a niche | Names what is missing, disputed or untested in that work | "Both use one state's data, and neither looks at rural districts on their own." |
| Occupy the niche | Says what this paper does and states its question; long papers add a map of the sections | "This paper tests whether the switch lowered math scores in rural districts." |
The example sentences are illustrative.
In a journal article, the moves usually play out over several paragraphs. Mensh and Kording describe a set of progressively more specific paragraphs1 that ends on what the literature lacks, then a final one on how the paper fills the gap. Their example narrows from what triggers cell differentiation, to one cell type, to an untested hypothesis about a single gene.
Start close to your topic
Make the first sentence about your subject. The UNC Writing Center lists the "dawn of man" introduction3 among its weak openings: sweeping claims about all of history that fail to connect to the thesis. Instructors, it adds, often find them extremely annoying. The dictionary definition is on the same list. Start instead with a specific fact, problem or disagreement from your sources.
Then say what is known, briefly. That means a handful of key studies, not your whole literature review. The International Committee of Medical Journal Editors (ICMJE) tells authors to cite only directly pertinent references4. If the paper has a separate review section, keep the full survey there; a literature review synthesis organizes one by claim rather than by author.
Write for a reader one field over. PLOS One asks for background that lets readers outside the field understand the purpose and significance5 of the study, so define terms they wouldn't know. Describe earlier work in the past tense ("Martin (2020) addressed") or the present perfect ("Researchers have studied"), as APA Style recommends6.
Name a gap you can defend
Build the gap from what your sources actually did: their data, setting, method and time period. The gap is where they stop, or where their results disagree. Logging each source's method and key finding, as in an annotated bibliography, makes that edge easy to see.
CARS offers four ways to establish the niche:
- Counter-claim: offer an opposing view, or point to a weakness in earlier work that undermines the prevailing argument.
- Indicate a gap: build the problem around an area the literature has missed or barely studied.
- Raise a question: ask what the gap leaves unknown, and say your study will answer it.
- Continue a tradition: extend earlier work to expand on or clarify the problem.
You don't have to run down earlier work to make room for yours. USC's guide suggests neutral, contrastive statements2 such as "Although research has been devoted to A, less attention has been paid to B."
Don't write "no one has studied this"
A reviewer can test that claim with one search, and may know the study you missed. Unless you searched systematically, say what "the studies reviewed here" did instead.
Say what your paper does
Close with the purpose. ICMJE asks authors to state the specific purpose, research objective or hypothesis4 of the study. Do it in one or two sentences, worded no more strongly than your evidence allows: "tests whether" for a hypothesis, "argues that" for a thesis.
Advice differs on whether to preview your findings. ICMJE says not to include data or conclusions from the work being reported4. PLOS One wants the introduction to end with the aim and a comment about whether that aim was achieved5. Mensh and Kording go further: the last paragraph compactly summarizes the results1. Check your target journal's author guidelines, or ask your instructor.
A short map of the sections that follow is the last step in the CARS model, and it helps readers find their way through long papers and theses. If you write in APA Style, leave off the "Introduction" heading: the paper's title acts as the heading7 instead.
In State X, 40% of rural school districts now teach four days a week, most to save on transport and staffing (Author A, 2019). The evidence on learning is mixed. Author A (2019) found a small drop in math scores after districts switched, while Author B (2021) found no change in math or reading.
Both studies, however, use a single state's data and pool rural districts with towns. Whether the four-day week lowers math scores in rural districts on their own remains unclear.
This paper uses 2015-2023 math scores from 120 districts in three states to answer that question. Section 2 describes the data, Section 3 the method and Section 4 the results.
- Territory. It opens on a cited fact about the topic, then shows that the two studies disagree.
- Niche. It names what both studies did and where they stop, so a reader can check it.
- Purpose. It states the question the paper answers, then maps the sections that follow.
Revise it against the finished paper
Finish the introduction after everything else. The UNC Writing Center suggests writing up your evidence first3, so the introduction matches the body of the paper. In a quantitative paper, that means drafting the statistical methods section and the results before you settle what the introduction promises.
Test the draft the way UNC suggests: ask a friend to read only the introduction and predict what the paper will discuss and what evidence it will use. If they can, the introduction is probably doing its job.
Before you hand it in
- The first sentence is about your topic, not all of history
- Every claim about earlier work cites a source you have read
- The gap names what those studies did and where they stop
- The question or thesis matches what the paper actually found
- Findings are previewed only if your journal or instructor expects it
- Terms a reader from a neighboring field needs are defined
When the draft is final, a reference and citation check tests each citation against the passage it cites. To draft the introduction itself from your notes and sources, start with the tool at the top of this page.
How it works
Start with what you have: a draft, notes, your sources, or all three, pasted or attached as files. River reads it all first, works out your question and the gap your sources leave, then writes the introduction in your workspace. It cites only what you supplied, in your citation style (APA 7 if there isn't one), and lists each claim that still needs a source.
If you haven't settled on a thesis, River drafts one from your material and marks it as a suggestion to confirm. It makes your argument clearer but never changes what you claim, and it never invents a source, author, year or finding.
Paste your material
Paste your draft, notes and sources, or attach the files. Add what the paper is and who reads it.
River finds the gap
It reads everything first, works out your question, and compares what your sources did to see where they stop.
Get your introduction
Cited paragraphs in your workspace, with a reference list and every claim that still needs a source.
Edit and refine it
Edit it, share it, or ask River to sharpen the gap, cut a third or switch citation style.
What you get
- An opening close to your topic, built on a fact or figure from your own sources
- What is already known, each claim cited to a source you supplied, in your chosen style
- The gap stated precisely: what your sources did, where they stop and where they disagree
- Your question or thesis in one or two sentences, worded no more strongly than the evidence
- A reference list of the sources cited, and a map of the sections when your field expects one
- A "Still needs a source" list: each bracketed claim and the kind of evidence that would support it
Common questions
What should a research paper introduction include?
It needs three parts: the background and key studies that frame your topic, the specific gap or dispute in that work, and what your paper does about it. It usually closes with the research question, hypothesis or thesis. Longer papers often add a short map of the sections, and some journals ask you to preview the main findings.
How long should a research paper introduction be?
There is no single rule: follow any limit your journal or instructor sets, and make it long enough to set up the gap and no longer. Without a set length, River aims for about 300 to 500 words in a class paper under 20 pages, and 600 to 900 in a journal article or thesis chapter.
What is the difference between an abstract and an introduction?
An abstract summarizes the whole paper, from question to results and conclusions, so readers can decide whether to read it. The introduction opens the paper itself: it explains why the study was needed and what it asks. For a thesis, the thesis abstract writer drafts the abstract inside your school's word limit.
Will River make up sources or citations?
No. River cites only the sources you paste or attach, and only for what those sources say. When a sentence needs support you didn't supply, it marks the sentence with [source for this claim]. Each one is listed after the draft with the kind of evidence that would support it, so you know what to look up.
How do I write a research paper introduction with River?
Paste your draft, notes and sources into the box at the top of this page, or attach the files. Add a line on what the paper is and who reads it. River finds the gap your sources leave and writes a cited introduction into your free River workspace, where you can edit it or ask for changes.
Can I use River for a class paper?
It depends on your instructor's AI policy, so check it first; rules differ by course and school. River writes only from your own argument, notes and sources and never invents evidence, so the research stays yours. You can also use the draft to see how the three moves fit, then write the final version in your own words.
Is the research paper introduction writer free?
Yes, it is free to start. Your introduction and its reference list open in a River workspace, where you can edit them, share them or ask River to change them. Paid plans add more AI use and access to the most advanced models.
Sources
PLOS Computational Biology. “Ten simple rules for structuring papers.” journals.plos.org (opens in a new tab)
USC Libraries. “Organizing Your Social Sciences Research Paper: The C.A.R.S. Model.” libguides.usc.edu (opens in a new tab)
UNC Writing Center. “Introductions.” writingcenter.unc.edu (opens in a new tab)
International Committee of Medical Journal Editors. “Preparing a Manuscript for Submission to a Medical Journal.” icmje.org (opens in a new tab)
PLOS One. “Submission Guidelines.” journals.plos.org (opens in a new tab)
APA Style. “Verb tense.” apastyle.apa.org (opens in a new tab)
APA Style. “Headings.” apastyle.apa.org (opens in a new tab)
Built by
Chandler Supple
Co-founder & CEO, River
Chandler has spent the last six years working in AI, building tools for millions of users and Fortune 100 companies. In 2025, he co-founded River to build a new kind of operating system for AI agents.