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Literature Searching

A step-by-step guide to the literature searching process

Define your research topic or question

Before you start searching, you should begin your search plan by focussing your research topic as much as possible, so that you are clear as to what research literature you are trying to find.

Defining your topic in a single sentence, or as a question, can help you do this. For example:

A poorly defined research topic:    “I need information on Type 2 diabetes”

A well-defined research question:    “Is obstructive sleep apnoea a risk factor for Type 2 diabetes?”

Once you've defined your research topic, you should follow the next steps, outlined below. Remember, searching is an iterative process and you may find you need to refine your question, concepts and alternative terms as you proceed.

Planning your search is important because natural language searches generally do not work so well in search tools such as Ovid and EBSCO. They are designed to make use of index terms via what is known as a controlled vocabulary.

Identify important concepts

Once you've defined your research question, you need to identify the key concepts. This is because of the way most specialist search tools such as Ovid, EBSCOhost and Healthcare databases advanced search (HDAS) operate.

Using our research question from above, for example, our key concepts would be:

1. Sleep apnoea     2. Type 2 diabetes     3. Risk factors

  • A framework like PICO can help identify the key concepts in your search
  • A search plan can be very useful to organise your thoughts and record your search terms. Keep a record of your search plans and strategies to include in your methodology, if required.

A search plan template can be downloaded below.

Consider alternative terms

Once you've identified your key concepts, you now need to consider any alternative terms to broaden your search and ensure that you do not miss any relevant literature.

Important things to consider include synonyms, spelling variations, plurals, and broader and narrower terms related to your concept.

For example, if one of our key concepts was Sleep Apnoea, our alternative terms might include:

Sleep apnea
Obstructive sleep apnoea
Obstructive sleep apnea
Sleep disorders

You can see from the above we've included spelling variations, an acronym and a broader search term in "sleep disorders".

Define any limits

As you plan you search, you might also want to consider if there are any limiting factors to your topic. For example, you might only want papers written in English, or that focus on a specific age range.

Specialist search tools such as Ovid, EBSCOhost  and HDAS allow you to apply a wide range of limits, including: publication date, age group, English language, full text (ie only those articles where the whole article is available), publication type and so on.

Decide where to search

As part of the search process, you also need to determine which health databases cover your topic.

On the SGUL Library website’s Databases pages, all the available databases are listed by name A – Z, and by Specialty. The list includes a brief description of the topic coverage for each database.