Thematic synthesis in a systematic review paper I have been currently conducting a systematic review. I used the classification framework approach, and I organized the articles in my field into three main categories (e.g. A, B, C). However, I am struggling to properly analyze the findings by summarizing the main ideas instead of separately/individually analyzing each article.

Can you give me some practical advice on how to better group the ideas? I tried with a systematic matrix.
Please excuse me for recommending my own work, but I've done quite a bit of work to address the problem: "I need to do a literature review. How do I organize it in a way that is useful to myself and to my readers?"

Actually, I answered a somewhat similar question before; I'm adapting my answer from there for you here. In brief, I recommend adopting a theory-extracting approach. That means to explicitly look for theory in the source articles and then to synthesize the theory as the contribution of the review. What I mean by "theory" is very simply "A is related to B". This is distinct from literature reviews that simply summarize what people have said about A; that is not theory. Theory is about explaining how and why phenomenon A is related to phenomenon B. In my academic field (information systems), I have found that this focus on theory is the most useful thing that can be done with literature reviews (in terms of citations by other researchers). Although my literature review approach focuses on social sciences, I believe it would be relevant in a case like yours.

I have two main relevant articles to recommend:


The View from Giants’ Shoulders: Developing Theory with Theory-Mining Systematic Literature Reviews: this describes the idea of theory-extracting reviews and focuses mainly on theory (I used to call them "theory-mining reviews")
A Guide to Conducting a Standalone Systematic Literature Review: this provides more practical details on how to actually conduct a general literature review