We live in an information rich world and being able to critically evaluate information is an important research skill. Reading and thinking critically means engaging with the information. Ask what is the main argument or what is the author trying to say and exercise judgement about the information source. Don't take everything you read at face value.

There are critical reading strategies and critical thinking processes you can apply.

An "original research article" reports the results of original or primary research and can take many forms. The article should also look at how the study adds knowledge to what is already known. 

When you start reading a scientific research article it will help if you understand what is included in the different sections and what you should look for. Have a look at the article below to get a few tips on how to read an article critically.

Subramanyam, R. V. (2013). Art of reading a journal article: Methodically and effectively. Journal of Oral & Maxillofacial Pathology,17(1), 65-70. https://doi.org/10.4103/0973-029X.110733

Once you have searched for information, you will need to critically appraise the studies you have found. This is a really important process because it ensures that studies with scientific flaws are disregarded, and the ones you include are relevant to your research question.

When evaluating primary research (research which hasn't been pre-appraised or filtered by others), you need to make sure the evidence you are including in your review is scientifically rigorous. The main questions to address are:

• Is the study relevant to your question?
• How scientifically did the researchers design the study, especially in their care to eliminate bias?
• What do the results mean and are they statistically valid (not just due to chance)?

For a more detailed look at Critical Appraisal, head to the Systematic Review Guide - Critical Appraisal and the Evidence-Based Practic Guide - Appraise.

If you're not completing a full systematic review and need to quickly analyse the studies you've retrieved, here are some considerations:

• Relevance - Compare the study to your search framework (such as PICO).
• Results - Were statistical tests applied and did they indicate the findings were statistically significant?
• Applicability to your research question - Did the researchers contribute to an answer to your original question? Is your study group similar to this or quite different? 
• Quality of study – There are many tools out there for a rapid critical appraisal of the study quality. For example, one you could use if you were reviewing controlled clinical trials is the RAMMbo appraisal method (Salisbury, Glasziou, & Del Mar, 2007):

R - Recruitment – were the subjects chosen in the study representative of the target population? Were there enough subjects to make the study valid?

A - Allocation – was the trial randomised?   

M - Maintenance – Was the status of the control group and study group maintained throughout the trial?  Were they treated the same way apart from the intervention?  

M - Measurement (Blinding, Objective measures) – were the outcomes measured objectively and the subjects blinded to the intervention?  Was bias eliminated as much as possible?      

Salisbury, J., Glasziou, P., & Del Mar, C. (2007). Evidence-based practice workbook: Bridging the gap between health care research and practice (2nd ed.). Oxford: Blackwell/BMJ Books.

Another handy tool for quick appraisal of health articles is from the Medical Research Council in the UK. Understanding Health Research takes you through a series of questions about a particular article, highlighting the good points and possible problem areas. You can print off a pdf summary at the end of your checklist.

Review papers summarise and evaluate the current knowledge on a selected topic. Common types of review articles include narrative reviews; systematic reviews and scoping reviews. Have a look at the Library's Literature Review Guide for more information on Types of literature reviews.

The article below can help you read and evaluate a review article.

Callcut, R. A., & Branson, R. D. (2009). How to read a review paper. Respiratory Care, 54(10), 1379-1385.