Literature Review Synthesis Matrix

The most common weakness markers point out in a literature review is that it summarises sources one after another — “Smith found… Lee found… Kim found…” — instead of comparing what they say. A synthesis matrix fixes that before you write a word. Sources go down the side, the same questions go across the top, and reading down a column shows you exactly what the literature says about one theme.

The columns and why they are there

The first seven columns are the same for every study: the citation, the title, the study’s aim or question, its design and method, the sample and setting, the key findings, and the limitations. Filling those in makes you read each paper the same way, and it is where differences in quality show: a small convenience sample, a cross-sectional design where a causal claim is made, or a setting that does not match yours.

Adding your themes

Theme columns are where the review takes shape. Name one for each thread of your argument — for a review on teenage sleep and school performance, perhaps “screen time”, “start times”, “measurement of sleep” and “grades versus wellbeing”. In each cell, note what that source says about the theme, or leave it empty if it says nothing. Add, rename and delete themes as your reading changes your view.

Starting from your reference manager

Instead of typing citations, paste the BibTeX, RIS or CSL-JSON export of your selected studies. Each becomes a row with its citation and title filled in: one author as Kim (2019), two as Smith & Lee (2021), three or more as Smith et al. (2021). Empty rows are replaced; rows you have already filled are kept.

Reading the matrix both ways

Read across a row to summarise a study. Read down a theme column to write a paragraph: which studies agree, which disagree, and why — different samples, methods or definitions. Under the table, the coverage figures show how many sources address each theme. A theme covered by one source, or none, is either a gap you can point out in the review or a theme to drop.

Exporting and keeping it safe

Download an Excel file to sort and filter by method or year, a CSV for other software, or copy the matrix as a Markdown table for notes apps. The matrix is saved in your browser as you type, but only on this device, so export a copy regularly.

A short example

Importing two references — an article by Smith, Lee and Cruz from 2021 and a 2019 book by Kim — creates two rows cited as “Smith et al. (2021)” and “Kim (2019)”, ready for notes, with each theme reading “0 of 2” until you fill it in.

From matrix to draft

Turn each theme column into a section of the review. Open it with the overall picture, compare the strongest studies, explain disagreements, and end with what is still unknown. The limitations column supplies the critical evaluation markers look for.

Related tools

Find studies with the Boolean Search Builder, convert reference files with the BibTeX Converter, format the final list with the Bibliography Formatter, or put summary tables into LaTeX with CSV to LaTeX.