Tag Archives: pilot study

Data collection, Disseminating findings, Ethics, pilot study, Research design, research methods

Pilot sTUdies: Look before you leap! (a priori vs. posthoc)

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Why does it matter if a study is labeled a “pilot”?

SHORT ANSWER: …Because a pilot is about testing research methods,….not about answering research questions.

If a project has “pilot” in the title, then you as a reader should expect a study that examines whether certain research methods work (methodologic research). Methods include things like timing of data collection, sampling strategies, length of questionnaire, and so on. Pilots suggest what methods will effectively to answer researchers’ questions. Advance prep in methods makes for a smooth research landing.

Small sample = Pilot? A PILOT is related to study goals and design–not sample size. Of course pilots typically have small samples, but a small sample does not a pilot study make. Sometimes journals may tempt a researcher to call their study a pilot because of small samples. Don’t go there. Doing so means after-the-fact, posthoc changes that were Not the original, a priori goals and design.

Practical problems? If researchers label a study a “pilot” after it is completed (post hoc), they raise practical & ethical issues. At a practical level, researchers must create feasibility questions & answers. (See NIH.) The authors should drop data analysis that answers their original research questions.

Ethics? This ethically requires researchers 1) to say they planned something that they didn’t or 2) to take additional action. Additional action may be complete transparency about the change and seeking modification to original human subjects’ committee approvals. An example of one human subjects issue is that you informed your subjects that their data would answer a particular research question, and now you want to use their data to answer something else–methods questions!

Options? You can just learn from your small study and go for a bigger one, including improving methods. Some journals will consider publication of innovative studies even when small.

Look first, then leap: Better to look a priori, before leaping. If you think you might have trouble with your methods, design a pilot. If you made the unpleasant discovery that your methods didn’t work as you hoped, you can 1) disseminate your results anyway or 2) rethink ethical and practical issues.

Who’s with me? The National Institutes of Health agree: https://nccih.nih.gov/grants/whatnccihfunds/pilot_studies . NIH notes that common misuses of “pilots” are determining safety, efficacy of intervention, and effect size.

Who disagrees? McGrath argues that clinical pilots MAY test safety and efficacy, as well as feasibility. (See McGrath, J. M. (2013). Not all studies with small samples are pilot studies, Journal of Perinatal & Neonatal Nursing, 27(4): 281-283. doi: 10.1097/01.JPN.0000437186.01731.bc )

Data collection, Evidence based nursing, evidence based practice, Methodologic research, Methods, research, Research design, research methods

Trial Balloons & Pilot Studies

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A pilot study is to research what a trial balloon is to politics. 

In politics, a trial balloon is communicating a law or policy idea via media to see how the intended audience reacts to it.  A trial balloon does not answer the question, “Would this policy (or law) work?” Instead a trial balloon answers questions like “Which people hate the idea of the policy/law–even if it would work?” or “What problems might enacting it create?” In other words, a trial balloon answers questions that a politician wants to know BEFORE implementing a policy so that the policy or law can be tweaked to be successfully put in place.

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In research, a pilot study is sort of like a trial balloon. It is “a small-scale test of the methods and procedures” of a planned full-scale study (Porta, Dictionary of Epidemiology, 5th edition, 2008). A pilot study answers questions that we want to know BEFORE doing a larger study, so that we can tweak the study plan and have a successful full-scale research project. A pilot study does NOT answer research questions or hypotheses, such as “Does this intervention work?”  Instead a pilot study answers the question “Are these research procedures workable?”

A pilot study asks & answers: “Can I recruit my target population? Can the treatments be delivered per protocol? Are study conditions acceptable to participants?” and so on.   A pilot study should have specific measurable benchmarks for feasibility testing. For example if the pilot is finding out whether subjects will adhere to the study, then adherence might be defined as  “70 percent of participants in each [group] will attend at least 8 of 12 scheduled group sessions.”  Sample size is based on practical criteria such as  budget, participant flow, and the number needed to answer feasibility questions (ie. questions about whether the study is workable).

A pilot study does NOT:  Test hypotheses (even preliminarily); Use inferential statistics; Assess safety of a treatment; Estimate effect size; Demonstrate safety of an intervention.

A pilot study is not just a small study.

Next blog: Why this matters!!

For more info read the source of all quotes in this blog: Pilot Studies: Common Uses and Misuses @ https://nccih.nih.gov/grants/whatnccihfunds/pilot_studies