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LibrarySkills@UCL for NHS staff

A guide to information literacy and library skills for NHS staff from Trusts supported by UCL Library Services, to inform clinical practice, study and research.

Evaluating information sources

To critically analyse /appraise or evaluate, means to:

  • break something down into its component parts
  • provide your opinion on each part, by asking the right kind of analytical questions
  • support your opinions with evidence

What is critical appraisal?

Once you have identified evidence for your search topic, you should critically appraise it. This is particularly important in medicine, nursing, pharmacy and other health sciences, where poorly conducted research can have a negative impact on patient outcomes.

Critical appraisal is the process of carefully and systematically examining research to judge its trustworthiness, and its value and relevance in a particular context. (Burls 2009, p.1)

The following resources will help inform most critical appraisal projects.

CASP checklists are widely used. See our additional guidance and examples for using CASP checklists for selected study designs:

Additional resources:


Bibliometrics is concerned with the analysis of research based on citation counts and patterns. The individual measures used are also commonly referred to as bibliometrics, or citation metrics.