Designing a Study You Can Defend
A pretest usually examines a specific instrument or procedure, a feasibility study investigates whether and how a future study can be done, and a pilot tests part or all of the intended future study on a smaller scale. The boundaries can vary across disciplines, so purpose matters more than the label alone.
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Designing a Study You Can Defend
You can test much more than a questionnaire before the full study begins. Recruitment, consent, participant procedures, intervention delivery, measurements, follow-up, data management, staff workflows, and planned analysis processes may all warrant testing when they contain meaningful uncertainty.
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Designing a Study You Can Defend
A data collection procedure is practical when researchers and participants can complete it consistently under realistic study conditions without unacceptable burden, missing data, resource demands, or operational problems. Testing the full workflow can reveal problems that an instrument alone cannot.
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Designing a Study You Can Defend
A pilot showing that the original design will not work is not necessarily a failed pilot. The finding may prevent a much larger failure by identifying what needs revision, further testing, or reconsideration before the main study begins.
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Designing a Study You Can Defend
There is no universal number or percentage of changes that turns a revised study into a different study. What matters is whether the modifications preserve the core research question and inferential structure or materially change what is being studied, in whom, how, and for what conclusion.
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Designing a Study You Can Defend
Random assignment strengthens causal inference by using chance rather than choice to allocate study conditions. It does not guarantee identical groups, representative samples, perfect implementation, or an unbiased study by itself.
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Designing a Study You Can Defend
A research protocol is the written plan for how a study will be conducted. Writing it before data collection makes key methodological decisions explicit, reviewable, and easier to distinguish from decisions made after seeing the data.
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Designing a Study You Can Defend
A research protocol should contain enough information to explain why the study is being conducted and exactly how it will be carried out. Its contents should reflect the study design and applicable requirements rather than a universal template.
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Designing a Study You Can Defend
A research protocol should be detailed enough for the study to be understood, critically reviewed, and implemented without guessing at consequential methodological decisions. More detail is not automatically better; the right level depends on the study and the purpose of the information.
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Designing a Study You Can Defend
Not every research decision must be permanently fixed before data collection. Legitimate flexibility is possible when the methodology requires adaptation, circumstances cannot reasonably be anticipated, or later decisions follow criteria established in advance.
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Designing a Study You Can Defend
A coherent research protocol creates an explicit chain from the research problem to the questions or objectives and then to the design, evidence, and analysis. Every major methodological choice should help answer a stated question rather than merely appearing reasonable on its own.
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Designing a Study You Can Defend
Sampling, measurement, data collection, and analysis should operate as one connected system. A strong protocol checks not only whether each component is defensible on its own, but whether the evidence produced at one stage is suitable for what the next stage requires.
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Designing a Study You Can Defend
A research protocol benefits from review by people who can evaluate its scientific logic, methods, analysis, feasibility, and ethical implications. The right reviewers depend on the study, and formal ethics review should not be confused with the broader methodological review a protocol may need.
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Designing a Study You Can Defend
A control group can make some research questions answerable, but not every study needs one. Whether you need a control depends on the contrast required by your question and the claim you intend to make.
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Designing a Study You Can Defend
Control group and comparison group are sometimes used interchangeably, but not always. The more important issue is what the group represents, how it was formed, and whether it provides the comparison your research question requires.
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Designing a Study You Can Defend
An appropriate comparison group is not simply a group that looks similar to the intervention group. It must represent the alternative required by the research question and support a credible interpretation of the resulting contrast.
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Designing a Study You Can Defend
Preregistration records important research decisions before the results are known, while Registered Reports add peer review before the study is completed. Neither requires researchers to predict everything perfectly or abandon legitimate changes and exploration.
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Designing a Study You Can Defend
Preregistration creates a time-stamped record of important research decisions before the relevant results are known. Its main value is making it easier to distinguish advance plans from decisions influenced by the data.
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Designing a Study You Can Defend
A useful preregistration specifies the decisions that matter for interpreting your eventual claims, not every minor detail of the study. Learn what usually deserves advance specification and how detailed the plan should be.
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Designing a Study You Can Defend
A protocol describes how you plan to conduct a study; preregistration creates a time-stamped record of research decisions before the relevant results are known. The same document can sometimes serve both purposes, but the concepts are not interchangeable.
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Designing a Study You Can Defend
Preregistration records a study plan before the relevant results are known. A Registered Report adds prospective journal peer review and in-principle acceptance, making publication less dependent on how the results turn out.
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Designing a Study You Can Defend
Preregistration can be valuable beyond conventional experiments, but not every study benefits in the same way. Its usefulness depends on which decisions can meaningfully be specified in advance and what transparency the advance record adds.
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Designing a Study You Can Defend
Qualitative research can be preregistered without pretending that its design is fixed or hypothesis-driven. A useful qualitative preregistration documents the study's starting point while preserving legitimate methodological adaptation.
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Designing a Study You Can Defend
Exploratory research can be preregistered without turning it into confirmatory research. The key is to preregister the starting point, scope, procedures, and decision rules you genuinely know in advance while leaving discoveries open.
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Designing a Study You Can Defend
You do not have to classify an entire study as either exploratory or confirmatory before collecting data. What matters is whether particular claims and analyses were specified before researchers learned from the evidence used to evaluate them.
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