Reading Notes: How to Write a Literature Review
Knopf (2006)
Knopf, J. W. (2006). How to write a literature review. PS: Political Science and Politics, 39(1), 127–132. https://doi.org/10.1017/S1049096506060264
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1 Introduction and Purposes of the Literature Review (pp. 127–128)
1.1 Defining the Literature Review and Its Three Contexts [§1–§4]
Jeffrey Knopf opens the article by acknowledging the relative scarcity of guidance on how to conduct literature reviews in political science and related social science methodology training. He notes the existence of some general research methods texts and a handful of dedicated guides on the topic, while observing that these are rarely cited or required in graduate training. The article positions itself as a practitioner-oriented overview, drawing in part on points from a lecture by Paul Pitman and a handout by John Odell for students at the University of Southern California.
In §2–§3, Knopf identifies three distinct contexts in which a literature review is produced and used. The first is a standalone review essay, whose purpose is to summarize and evaluate the existing state of knowledge on a subject for the scholarly community. The second is the literature review section of a research proposal, which serves to justify the proposed research by demonstrating where a gap in knowledge exists or where a debate remains unresolved. The third is a literature review in a finished research report, such as a thesis or dissertation, where it situates the author’s final conclusions within the broader scholarly conversation. In §4, Knopf emphasizes that this third form generally builds on and revises work completed at the proposal stage, serving to show how the final findings relate to prior wisdom about the subject.
1.2 Ways to Frame the Contribution to Knowledge [§5–§9]
In §5–§6, Knopf introduces a framework for thinking about what it means to “contribute to knowledge.” He is careful to note that knowledge in the social sciences does not mean “Truth” with a capital T, but rather refers to beliefs — specifically, beliefs that individuals hold with varying degrees of confidence as a result of study or experience. Because many social science hypotheses cannot be proven conclusively, literature reviews typically engage with the “claims” or “arguments” advanced by studies or schools of thought, and assess the strength of the support offered for those claims.
In §7–§9, Knopf explicitly draws an analogy to Bayesian analysis: just as a Bayesian statistician revises the estimated probability of a proposition being true upon acquiring new data, a researcher can attempt an analogous qualitative assessment. This framework suggests that a contribution to knowledge may involve (a) creating an entirely new belief where none existed before (new factual information, a new theoretical proposition, or a new policy proposal); (b) strengthening an existing belief through corroborating evidence; or (c) challenging an existing belief through contradictory evidence or analysis. Knopf anchors this Bayesian analogy not as a call for quantification, but as a conceptual heuristic for identifying where new research can make a difference by locating existing beliefs and their levels of confidence.
1.3 Casting the Net Widely: Beyond Traditional Academic Sources [§10–§13]
In §10–§12, Knopf argues that while the traditional literature review focuses on peer-reviewed books and journal articles, the growth of alternative research producers and Internet-based dissemination makes it advisable to consider a wider range of sources. He suggests that “review of existing knowledge” is a more accurate term for this enterprise than “literature review” per se. The entities that might produce relevant research include government agencies, international governmental organizations, non-governmental organizations, think tanks, and independent researchers. Conference papers, working papers, and monographs posted online also represent scholars’ most current thinking and may not yet be published in traditional outlets.
In §13, Knopf issues a careful caveat: the Internet must be used with great caution, since — unlike peer-reviewed publications — anyone with access to the necessary equipment can post content without submitting to scholarly scrutiny. He recommends screening Internet postings for author credentials, source documentation, and the credibility of their evidence base. If the research interest involves existing policy proposals or practices, academic credibility may matter less than whether the source is in a position of authority or has inside knowledge — but even then, researchers must screen out postings that lack a valid basis for their assertions.
2 Pointers for an Effective Literature Review (pp. 128–129)
2.1 Seven Practical Guidelines for Conducting a Review [§14–§20]
In §14, Knopf opens his practical guidance with the suggestion that researchers — especially those producing their first literature review — should begin by reading existing review essays to observe how other researchers have carried out the task, imitating what seems effective and avoiding what seems unnecessary or unhelpful. Graduate-level course assignments and advisor recommendations are identified as natural first sources for such models.
The second pointer (§15) concerns the ability to succinctly summarize each study’s main claim. The researcher should be able to describe in one or two sentences the central argument of each item read, even if not every such description ultimately appears in the written review. This discipline ensures conceptual clarity and facilitates comparison across works.
In §16–§17, Knopf introduces the third and fourth pointers: selectivity and intellectual ordering. The written review should not discuss every item read, but only those with a direct bearing on the central focus. More crucially, the review should not be structured as a sequential summary — “paragraph 1 notes that book A says X; paragraph 2 notes that article B says Y” — but should instead impose conceptual organization on the material.
In §18–§19, the fifth through seventh pointers are developed. Grouping studies into “camps” or “schools of thought” (by theoretical perspective, methodological approach, or policy orientation) allows the review to efficiently convey that multiple authors share a position without devoting separate paragraphs to each. Knopf notes that for well-developed subjects, other scholars will often have already classified the research into contrasting schools of thought — encyclopedias, handbooks, review articles in academic journals, and dissertation literature review chapters are flagged as useful resources for orienting oneself to an established field. He issues a caution (§19) against relying exclusively on others’ summaries: reading the most critical sources oneself and drawing independent conclusions is essential. The final pointer (§20) is to form the habit of associating individual author names with theoretical camps, since academic writing routinely uses author surnames as shorthand for theoretical traditions (e.g., “Waltzian” for neo-realism).
3 The Nuts and Bolts: What the Review Must Answer (pp. 129–131)
3.1 Four Tasks of the Literature Review [§21–§26]
In §21–§22, Knopf identifies four core tasks that most literature reviews must address. The first two are analytical prerequisites: determining what each study examined (its dependent variable, conceptualization, operationalization) and what each study concluded (its thesis, its level of confidence in its findings, and its stated qualifications). These two steps are essential before collective results can be meaningfully compared, since different studies may reach different conclusions simply because they asked different questions or defined the phenomenon of interest in different ways.
In §23–§26, Knopf elaborates on the third task — summarizing existing studies — through a three-category typology. (1) Areas of consensus or near-consensus represent the “conventional wisdom” about a subject; these involve shared beliefs (positive or negative) about what is true or what works. (2) Areas of disagreement or debate produce alternative “camps” or “schools of thought.” (3) Gaps refer to aspects of a topic not yet examined — unanswered questions, unexplored perspectives, or unanalyzed bodies of information. Knopf stresses that once these three categories are identified, the literature review can precisely describe the proposed research’s contribution and why it will matter to the intended audience. Contributions may address any of the three: challenging conventional wisdom, weighing in on an existing debate, or filling an empirical or theoretical gap.
3.2 Evaluating the Quality of the Literature [§27–§31]
In §27–§29, Knopf addresses the fourth task: assessing the quality of the literature. This involves examining four dimensions of how scholars have reached their conclusions. The first is assumptions — whether disagreements among studies can be traced to different foundational premises, and whether those premises are plausible or so problematic as to undermine the analysis that rests on them. The second is logic — whether the reasoning offered by each study is internally consistent and logically persuasive, or whether it proceeds by assertion and contains internal contradictions or “giant leaps” at critical analytical junctures.
In §30–§31, Knopf addresses evidence and methodology. Regarding evidence, the key questions concern whether claims are empirically documented, whether the evidence is factually accurate and on-point, whether all relevant cases and data have been considered, and whether selection bias might have affected the results. Regarding methodology, the review should evaluate whether the methods used were appropriate for the question being asked and whether they were applied correctly. By systematically identifying and comparing the assumptions, theories, data, and methods of studies, the reviewer can pinpoint the underlying disagreements responsible for debates in the literature and target their own research accordingly.
4 Managing Sources: Too Few and Too Many (pp. 130–131)
4.1 The Two-Tier Framework for Thin Literature [§32–§36]
In §32–§33, Knopf addresses the common situation where students believe no literature is available on their topic. He recommends conducting a serious search before concluding that the topic is virgin territory, noting that a thorough search that uncovers nothing is itself valuable evidence for a research proposal’s claim to originality. When sources are genuinely scarce, Knopf proposes thinking in terms of two tiers (or circles) of literature.
In §34–§36, the first tier (inner circle) covers publications that directly address the proposed research question. The second tier (outer circle) encompasses work that overlaps with some aspect of the question — for instance, studies employing a theory that could be applied to the topic even if it has not been used in that specific context, or research on analogous situations. Knopf illustrates this with the example of agro-terrorism research: if no literature exists on protecting crops from agro-terrorism, a researcher might consult work on protecting crops from natural disease outbreaks and assess whether those techniques could be adapted. The analogy-based expansion of scope allows the review to situate a novel topic within existing intellectual frameworks.
4.2 Strategies When There Are Too Many Sources [§37–§40]
In §37–§38, Knopf identifies the opposite problem — an abundance of potentially relevant literature — that often arises once the researcher expands to the second tier and encounters well-developed theoretical fields. He warns against selecting sources at random (e.g., whatever happens to be on the library shelf or appears in the first Google results), since random selection risks producing a review that does not accurately represent the current state of knowledge and debate.
In §39–§40, Knopf offers three rules of thumb for restricting focus when sources are abundant: (1) prioritize leading authorities — authors and studies that are frequently cited in the literature; (2) emphasize recent studies from high-prestige outlets — books from highly ranked university presses and articles in leading journals, as well as high-visibility sources; and (3) focus on studies most directly relevant and helpful for the research question. He concludes that when there is a great deal of literature, comprehensiveness is not required; the review should focus on those parts of the literature that relate to and advance the researcher’s specific interests.
5 The Bottom Line (pp. 131–132)
5.1 Summary Criteria and Guiding Questions [§41–§44]
In §41–§42, Knopf provides a concluding summary of what a literature review should accomplish: it should concisely summarize, from a set of relevant sources, the collective conclusions most pertinent to the researcher’s own interests, and evaluate the state of knowledge in terms of what is right, what is wrong, what remains an unresolved area of uncertainty, and what is missing because no one has carefully considered it.
Knopf’s operative synthesis is that proceeding systematically and aiming at a considered judgment about the state of knowledge on a subject transforms the literature review from a passive summary exercise into an independent contribution to knowledge in its own right.
In §43–§44, Knopf closes with a checklist of guiding questions for constructing a rigorous review: What questions have existing publications addressed, and what has been neglected? What are the main conclusions, and where do studies converge or diverge? What theories, policies, or evidence have been examined, and what potentially relevant alternatives have not? How solid are the existing conclusions? What are the most important remaining problems and gaps? These questions apply regardless of whether the review is a standalone essay, part of a research proposal, or a component of a thesis or dissertation.
6 Synthetic Argument
Critical Analytical Sheet
This section follows the IA Spreadsheeting Texts v13.1 format. The analysis is adversarial without being destructive: it identifies real vulnerabilities in the argument and acknowledges genuine contributions with equal precision. The analytical reasoning underlying each dimension is recorded in the Analytical Reasoning field of the table.