Evidence: Types and Sources of Information

We went over the parts of a scientific claim

• Claim
• Prediction
• Evidence
• Reasoning
• Logic

We then looked at the criteria for good evidence

• sample size
• sample selection
• researcher bias
• confounding factors

It can be difficult to assess the quality of scientific evidence, especially if the topic is one that I am not familiar with.  Therefore it  can be very helpful to look at the type and sources of scientific information. This can help me figure out what to rely on and what to examine more closely. 

Types of sources include:

Primary Sources 

• Research studies performed, written, and then submitted for peer-review to a scientific journal
  that build upon and include references to previous research studies. These include original data in the form of graphs or data tables
  from research studies. 
• Peer Review: means that ''peers'' or scientists in the same field reviewed and critiqued the paper. This is the ''gold standard'' since it means that experts have evaluated the quality of the research. 
• Example; 

• Reviews of several research studies written up as a summary article with references.
• These can appear in peer-reviewed academic journals but they can also appear in online journals or from government agencies.
• They always contain complete citations and references and present a thorough review of the current state of research. 
• Example 

Dr Subodh Kumar Pathak, Dr Abhijeet Ashok Salunke, Dr Praveen Thivari, Apurva Pandey, Dr Kunal Nandy, Dr Harish V K Ratna, Dr Sanjay Pandey, Dr Jasneet Chawla, Dr Jalil Mujawar, Dr Anant Dhanwate, Dr Vivek Menon,
No benefit of hydroxychloroquine in COVID-19: Results of Systematic Review and Meta-Analysis of Randomized Controlled Trials”, Diabetes & Metabolic Syndrome: Clinical Research & Reviews, Volume 14, Issue 6, 2020

• Article in a newspaper or popular magazine. These media reports are written by identified journalists not posted anonymously.
  These rarely contain complete citations or references with names of all researchers and exact source of publication but will usually
  report the names of primary researchers and often refer to the publisher. 
• Government warnings as consumer updates often posted to U.S. Department of Health and Human Services Websites. E
• Encyclopedia entries such as Wikipedia that contain some citations and references, but the content of the article may or may not
  have been fact checked.
• Example

FDA cautions against use of hydroxychloroquine or chloroquine for COVID-19 outside of the hospital setting or a clinical trial due to risk of heart rhythm problems

What are the best resources to use?

While peer reviewed primary literature is the best source of information, it can be very difficult to read and understand these articles. Therefore, a good quality review article or trusted source like the FDA publication above can be invaluable when we begin to investigate a topic.

Apply your knowledge:

Answer these questions to test your understanding. You will be have 3 attempts to take the quiz. 

When you are done, you will go on to the next activity and  learn how to use the library resources to find information.