A literature review is far more than a summary of existing research—it's a critical analysis that demonstrates your scholarly expertise and positions your research within the broader academic conversation. This guide will help you write a literature review that impresses your committee and strengthens your dissertation.
Purpose of a Literature Review
Your literature review serves multiple essential functions: Establishing credibility by demonstrating comprehensive knowledge of your field. Identifying gaps in existing research that your study will address. Providing theoretical foundation for your research design and analysis. Preventing duplication by showing how your work differs from existing studies. Informing methodology by revealing which approaches have worked in similar contexts.
Finding Relevant Sources
Start with academic databases like Google Scholar, JSTOR, PubMed, or discipline-specific databases. Use strategic keyword combinations and Boolean operators (AND, OR, NOT) to refine searches.
Search strategies: Begin with seminal works in your area (often cited repeatedly). Use 'cited by' features to find newer research building on foundational studies. Review reference lists of relevant papers (backward snowballing). Set up alerts for new publications on key topics.
Source quality: Prioritize peer-reviewed journal articles and academic books. Be selective—a 50-source review of highly relevant work beats a 200-source review of tangentially related studies.
Organizing Your Review
Thematic organization is almost always preferable to chronological or author-by-author approaches. Group sources by themes, concepts, or debates rather than listing what each author said.
Common organizational structures: By theme or concept (most common), by methodology (useful for methods-focused reviews), by theoretical perspective, by chronological development of ideas (for historically-oriented fields), or funnel structure (broad context narrowing to your specific focus).
Create an outline before writing. Identify 4-7 major themes and organize your sources under each. Use citation management software (Zotero, Mendeley, EndNote) from the beginning.
Synthesizing vs Summarizing
The difference between a weak and strong literature review is synthesis. Summarizing describes what individual sources say. Synthesizing identifies patterns, connections, and contradictions across sources.
Poor synthesis: 'Smith (2020) found X. Jones (2021) found Y. Brown (2022) found Z.'
Strong synthesis: 'While early research focused on X (Smith, 2020), more recent studies have revealed the importance of Y (Jones, 2021; Brown, 2022), suggesting a shift in understanding toward...'
Ask yourself: What do these sources say to each other? Where do they agree or disagree? What patterns emerge across studies? What questions remain unanswered?
Identifying Research Gaps
Your literature review should naturally lead to the gap your research addresses. Gaps can take several forms: Empirical gaps (topics not yet studied), theoretical gaps (unexplored theoretical perspectives), methodological gaps (new methods that could yield different insights), population gaps (understudied groups or contexts), and practical gaps (research findings not yet applied).
Frame your gap constructively. Rather than criticizing existing research, position your work as extending or complementing it.
Writing Tips
Use present tense for established knowledge and past tense for specific study findings. Maintain your scholarly voice—summarize sources in your words, don't string together quotes. Be critical—evaluate methodology and validity, don't just accept findings uncritically. Update continuously—literature reviews are never truly 'finished' until your dissertation is submitted.
Common Mistakes to Avoid
1. Organizing by author instead of theme. 2. Including every source you read rather than curating strategically. 3. Summarizing without synthesizing. 4. Losing your own voice in a sea of citations. 5. Failing to connect the review to your research questions.
