RESEARCH GUIDE
The Dissertation Literature Review Chapter
Search Strategy and Synthesis
A literature review earns trust when a reader can see how studies were found, chosen and compared. The statistical parts are the search record, the eligibility rules and the way results from different studies are placed side by side.
WHERE STATISTICS ENTER
Statistical Care in a Literature Review
Five habits turn a summary of earlier studies into evidence that a committee can audit, and each can be documented as the review proceeds.
A dissertation literature review surveys and weighs the earlier research on a question, and its literature review structure usually moves from the broad field to the specific gap the study addresses. Which studies count, the argument built on them and the prose belong to the researcher. OnlineSPSS, a specialist statistical consultancy for academic, clinical and professional research, supports the statistical component through an in-house PhD-level statistician, from the planning of a formal evidence review to the quantitative comparison of effect estimates.
A Search Record That Can Be Repeated A literature search strategy lists the databases, the exact search strings, the date of each search and the limits applied, so another reader could run it again. The record is kept as a table or an appendix item, not left to memory.
Eligibility Set Before Screening Inclusion and exclusion rules are stated in terms of population, exposure or intervention, comparator, outcome and design, then applied the same way to every record. The counts at each stage are kept for a flow diagram.
Effect Sizes in Place of Verdicts Studies are compared by their estimates and intervals on a common scale, not by tallying how many reached significance. A tally ignores sample size, so a large study and a small one would count the same.
Appraisal Matched to Design Each study is judged with a quality or risk-of-bias tool that fits its design, for example RoB 2 for randomized trials, and the judgments are shown next to the findings they qualify.
Pooling Only Where Studies Compare Combining estimates is justified when studies address the same question with comparable measures and designs, and the variation between studies is reported with the pooled value. Otherwise a structured narrative with a results table is more honest.
FREQUENTLY ASKED QUESTIONS
Questions About the Literature Review
How formal the search must be depends on the kind of review, and a small evidence base changes what the review can conclude.
Does the review need a formal search protocol?
Not always: a narrative review inside a dissertation can be less formal, but its search should still be documented well enough to be repeated. A review that is itself the research design, with a stated question, registered methods and a flow of records, follows a protocol and a reporting guideline such as PRISMA 2020. Your supervisor or department sets the level of formality expected, and a clear search record is valued at either level.
What if only a few studies exist on my topic?
Say so, and present each study with its design, estimate and interval in one table. With only a few studies, the variation between them cannot be estimated precisely, so a pooled value can look more certain than the evidence allows. The shortage is itself a finding of the review, and it can show why the new study is needed.
How do you protect my research data and confidentiality?
Your dissertation materials and project details are handled confidentially. Project information is not published, and researcher names and institutions are not used publicly without permission. An NDA is available where required and can be arranged before sensitive materials are shared. Read more about confidentiality and data security.
What happens when I request an assessment, and how long does it take?
You share your research question, design and relevant materials, such as a protocol, an analysis plan or a dataset, and a statistically trained Research Coordinator reviews the request and responds the same day. The analysis, deliverables, timeline and one fixed project fee are then confirmed before any work begins, so the timeline follows from the agreed scope.
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NEXT STEP
Is a Quantitative Synthesis
Part of Your Review?
Extraction sheets, the case for or against a pooled estimate and the reporting of variation between studies benefit from a second statistical view. Statistical support for the synthesis would start from the studies that passed your screening.
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