Source credibility is " a function of the reliability of the processes used by the source" (Chinn and Rinehart, 2017: 1710). Whether an expert is credible in what they write will depend on the processes used to generate the evidence. The processes used to generate the evidence will vary depending upon the subject. The research methods used and their validity is a more accurate evaluation of the credibility of the source than relying just on source features. Initial evaluation criteria of both qualitative and quantitative studies are detailed in Tables 3.6 and 3.7 of Hart (2018: 83) and appear in Fig. 1 below. These can be used as a basis of your own criteria:
|Key evaluation criteria||Key questions to probe deeper|
Is there sufficient primary data to warrant the author's interpretation? Is the interpretation plausible?
|Transparency||What research methods were used to create the source? Are the methods suited to the aims of the study?|
Are there multiple sources of evidence? How reliable are these? Are there alternative sources of data that could have been used?
Checking that other sources corroborate the information presented takes more effort than other strategies but remains "a fast and frugal means of arriving at a credibility judgment" (Metzger and Flanagin, 2013: 215). Out of 84 first year students in a study at Brigham Young University, 81 used sources in the article as a way to evaluate its reliability. This varied from commenting on what facts were sourced, whether a specific institution or organization was named as the source of the evidence or when an opinion had no supporting evidence (Silva et al., 2018).
|Defined and measurable variables||Have these variables been isolated and defined? Can the variables be measured? Is there a standard way of doing so and has it been used?|
|Validity||Is the sample representative of the population being studied? Has the sample selection minimized the possibility of bias? What is the significance that the sample gives to the results?|
|Reliability||How were threats to the accuracy of the samples and the research methods used addressed? Are the research methods transparent? Has the reliability of the research methods been confirmed?|
You are more likely to rate more highly sources that produce empirical evidence based on sound research methods.