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Food Systems, Nutrition, and Health Guide

Guide to library resources and techniques relevant to the Food Systems, Nutrition, and Health program.

How to Write a Research Question


What characterizes a good question?

  • Well-conceptualized
  • Relevant
  • Direct and clear
  • Focused
  • Includes all components (main concepts)

Why should I formulate a structured research question?

  • To point you in a specific direction (narrowing your scope/focus to ask a manageable question)
  • To identify the main concepts of your question
  • To help build your literature search strategy
  • To improve your information retrieval
  • To be able to evaluate the usefulness/appropriateness of the information retrieved 

Identifying Key Concepts and Search Terms

Using a framework to develop your research question can help to identify the main concepts of your review topic (see further down the page). Whether you use a framework or not, the goal is to identify the main concepts of your question and the synonyms / similar terms that might be used to describe each of those concepts:

Combining search terms with Boolean operators (AND, OR, NOT) and parentheses:


Use AND to combine different main concepts of your search: Childhood AND Asthma. Narrows results (see gray overlapping section of Venn diagram). 

Venn diagram of Childhood AND Asthma:

venn diagram of childhood AND asthma with overlapped section in gray


Use OR to include similar terms / synonyms (and sometimes antonyms) for a concept: childhood OR adolescence. Fertility OR infertility. Broadens results (see Venn diagram with all sections shaded in gray). 

Venn diagram of Childhood OR Adolescence: 

venn diagram of Childhood OR Adolescence with all parts in gray


When you use synonyms and different concepts, you will need parentheses similar to the order of operations in math. Example: (childhood OR adolescence OR children) AND (asthma OR wheezing). This tells the database that any of the child terms must be in the article along with any of the asthma terms, but an article may not have just a child term or just an asthma term.


Use the Boolean operator NOT with caution. You will miss out on articles that talk about both concepts. For example: Child NOT Adult will miss articles that talk about children and adults, which may mean you don't see a key piece of information about your topic. To find information about children, the safer method is to include Child as a concept (e.g., AND (child OR childhood OR children OR kids)) to your search instead of 'NOTting' out Adults. 

Venn diagram of NOT Adult when you want to see information about children; the center slice could contain relevant information about children that you would miss by using NOT Adult:

venn diagram of Child NOT Adult with only the Child portion in gray, the center slice and Adult portion are white.

Another example from Slippery Rock University Bailey Library using Peanut Butter and Jelly may further clarify the use of Boolean operators and parentheses. 

Considerations for searching:

It is not always necessary to include all of your main concepts in the search. In some PICO questions, the outcome (O) is implied and does not need to be included. In other cases, any and all outcomes might of interest and so the search strategy can leave this out to keep it open.

Example research question: In seniors with dementia, does a falls prevention program, compared to no falls prevention program, result in decreased falls?

  • In the above PICO question, the comparator (C) can be left out of the search strategy as there is no great way to search for "not" having the intervention (in contrast to when there is a placebo or an alternate intervention as a comparison)
  • Also, the intervention (I) somewhat implies the outcome (O), so the outcome (decreased falls) can be left out of the search strategy
  • The main concepts that should be included in this particular search are: seniors (P1), dementia (P2), and falls prevention (I). Keep in mind though that there are different ways of describing these three concepts and so synonyms / similar terms are important to include in the search as well

Frameworks for Research Questions

Applying a framework when developing a research question can help to identify the key concepts and determine inclusion and exclusion criteria.

  • PICo: Population/Participants, phenomenon of Interest, Context
  • PICO(S): Patient/Problem, Intervention, Comparison, Outcome, (Study design)
  • PECO(S): Patient/Problem, Exposure, Comparison, Outcome, (Study design)
  • PESICO: Person, Environment, Stakeholders, Intervention, Comparison, Outcome
  • PIPOH: Population, Interventions, Professionals/Patients, Outcome, Healthcare Setting
  • PS: Population, Situation
  • SPICE: Setting, Perspectives, Intervention, Comparison, Evaluation

Example: PICO Questions

P (Patient, Population, Problem) I (Intervention) C (Comparison) O (Outcome)
How would I describe a group of patients similar to mine? What main interventions, prognostic factors or exposure are you considering? What is the main alternative to compare with the intervention? What can you hope to accomplish, measure, improve or effect?


Otherwise healthy children…


exposure to in utero cocaine…


children not exposed to in utero cocaine…

Result in:

increased risk of learning disabilities?


Primary school children


school-based physical activity


no school-based physical activity

Result in:

a decrease in obesity

Example: SPICE Question

S (Setting) P (Perspective) I (Intervention) C (Comparison) E (Evaluation)
Where? For whom? What? Compared with what? With what result?
In the setting of rural communities From the perspective of a pregnant woman How does facility-based care Compare with traditional birth attendants at home In relation to the woman’s perceptions and experiences?

Example from: Booth, A., Noyes, J., Flemming, K., Moore, G., Tunçalp, Ö., & Shakibazadeh, E. (2019). Formulating questions to explore complex interventions within qualitative evidence synthesis. BMJ Global Health, 4(Suppl 1), e001107.

Example: Nutritional Sciences

Search strategy development in the Food Systems, Nutrition, and Health Guide.

Formulating Research Questions

Underdeveloped question: 

What interventions help against vaping in youth?

Refined research question:

What strategies are effective for preventing nicotine vaping in youth?


The content of this page is almost entirely from Queen's University Library's Public Health Guide.