Dr. Christine Photinos, a writing professor at National University, offers some suggestions regarding synthesizing source:
Synthesis is something you already do in your everyday life. For example, if you are shopping for a new car, the research question you are trying to answer is, "Which car should I buy"? You explore available models, prices, options, and consumer reviews, and you make comparisons. For example: Car X costs more than car Y but gets better mileage. Or: Reviewers A, B, and C all prefer Car X, but their praise is based primarily on design features that aren't important to you. It is this analysis across sources that moves you towards an answer to your question.
Early in an academic research project you are likely to find yourself making initial comparisons - for example, you may notice that Source A arrives at a conclusion very different from that of Source B - but the task of synthesis will become central to your work when you begin drafting your research paper or presentation.
Remember, when you synthesize, you are not just compiling information. You are organizing that information around a specific argument or question, and this work - your own intellectual work - is central to research writing.
Below are some questions that highlight ways in which the act of synthesizing brings together ideas and generates new knowledge.
How do the sources speak to your specific argument or research question?
Your argument or research question is the main unifying element in your project. Keep this in the forefront of your mind when you write about your sources. Explain how, specifically, each source supports your central claim/s or suggests possible answers to your question. For example: Does the source provide essential background information or a definitional foundation for your argument or inquiry? Does it present numerical data that supports one of your points or helps you answer a question you have posed? Does it present a theory that might be applied to some aspect of your project? Does it present a recognized expert's insights on your topic?
How do the sources speak to each other?
Sometimes you will find explicit dialogue between sources (for example, Source A refutes Source B by name), and sometimes you will need to bring your sources into dialogue (for example, Source A does not mention Source B, but you observe that the two are advancing similar or dissimilar arguments). Attending to interrelationships among sources is at the heart of the task of synthesis.
Begin by asking: What are the points of agreement? Where are there disagreements?
But be aware that you are unlikely to find your sources in pure positions of "for" vs. "against." You are more likely to find agreement in some areas and disagreement in other areas. You may also find agreement but for different reasons - such as different underlying values and priorities, or different methods of inquiry.
(See also Identifying a Conversation)
Where are there, or aren't there, information gaps?
Where is the available information unreliable (for example, it might be difficult to trace back to primary sources), or limited, (for example, based on just a few case studies, or on just one geographical area), or difficult for non-specialists to access (for example, written in specialist language, or tucked away in a physical archive)?
Does your inquiry contain sub-questions that may not at present be answerable, or that may not be answerable without additional primary research - for example, laboratory studies, direct observation, interviews with witnesses or participants, etc.?
Or, alternatively, is there a great deal of reliable, accessible information that addresses your question or speaks to your argument or inquiry?
In considering these questions, you are engaged in synthesis: you are conducting an overview assessment of the field of available information and in this way generating composite knowledge.
Remember, synthesis is about pulling together information from a range of sources in order to answer a question or construct an argument. It is something you will be called upon to do in a wide variety of academic, professional, and personal contexts. Being able to dive into an ocean of information and surface with meaningful conclusions is an essential life skill.