Answered By: Marc Forster
Last Updated: 04 Aug 2015     Views: 981

The first stage of any search should be to define what it is you are looking for. This might sound obvious, but it is part of the search process which people commonly do not put enough thought into. There is a lot of information out there - unless you are quite specific, you will find sifting through it very time-consuming.

Try and turn your topic into a question (or a number of questions!) you want the literature to answer. There is a framework called PICO, or sometimes PICO(ST), which you can use to help with this. Each letter stands for a possible aspect of your topic.

P - Population: Is there anything about the people/group you are studying that makes them different from the general population? For example, are they from a particular age group, gender or ethnic background? Are they pregnant? Are they students?

I - Intervention: This is the thing that is being done to or by your population that you want to know more about. Are they smoking? Do they cycle to work? Do they use social media? Are they exposed to pollution?

C - Comparison: Optional - do you want to you compare two different interventions (e.g. cycling to work vs driving to work?) 

O - Outcome: What do you want observe about how the intervention affects your population?

You may also want to consider the other two letters of PICO(ST):

S - Situation: The context where what you want to study is taking place. For example a particular country or group of countries, or a particular setting or type of environment (e.g. Low and Middle Income Countries, hospitals, public/private sector employment)

T - Type of evidence: Is there a particular type of information you want that will best answer your question? Will the answers be in peer-reviewed academic literature, government statistics, NGO reports, newspapers? Will the information be quantitative or qualitative (or a bit of both)? 

You won't always need every aspect of PICO(ST) in your literature search questions - this is just a guide to help you try and refine a gneral topic into something more clear and specific.

You should also think about any limits to what information will be useful to you for your purposes. How recent must it be to be relevant? Where in the world should it come from? In what language(s)?

Thinking about your topic with this framework should help you identify a question, or a series of questions, that are specific enough to use for a literature search.

For example, if you are interested in screening for open angle glaucoma, you might identify several questions about this topic using PICO(ST), each of which might need their own literature search. Some of these questions might be:

Where in the world are there national or regional programmes of screening for open angle glaucoma?
What are the methods of screening for open-angle glaucoma?
Is there any evidence that screening for open-angle glaucoma is cost-effective?

However, you can't just enter the question in as it is and get all the results you need in most search resources. Bibliographic databases, for example, are very literal, and will only look for EXACTLY what you type in to them. To conduct a good search, you will need to identify the main concepts within your question; identify all the relevant synonyms for each concept; and create searches from these using Boolean operators. See the FAQs below for more help with this.

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