Validity of sources of information

In compilation of any report, the quality of the referenced sources is an important indicator of the standard of your work. To a first approximation, the ranking from best to worst, might be:

• Refereed journals
• The text should have been reviewed by two-four independent experts (though some are more thorough than others)
• Elsevier, Sage and Taylor & Francis Group, plus professional institutes/institutions, publications are good in the composites area.
• If the journal uses Digital Object Identifier (DOI), it is probably more reliable than (a less prestigious) one with no DOI.
• Check the acknowledgements for sponsors (commercially-sponsored research is likely to skew differently from those for environmental lobby groups)
• Do the authors clearly state testing is to recognised standards and using calibrated equipment.
• Edited books
• The text would normally be reviewed by one or more of the editors, and sometimes more widely.
• The writing and publishing process often takes 18-24 months so the text will not include recent developments.
• Research degree theses
• Normally the repository copy will have been examined and corrected before deposit.
• Monographs, theses and dissertations
• The text may, or may not, have been reviewed by colleagues/friends of the author.
• Magazines/newspapers
• Can be of very variable quality, but articles are often “dumbed down” to cater to a lay audience
• Conference papers, lecture notes and conversations with individuals
• The opinion of one individual which may be (a) biased by selective reading or personal agenda, and (b) often not subject to independent review.
• Supplier data sheets
• Assume they selectively quote the best available data, and check whether they state the standards to which test were conducted
• Webpages
• These can vary from publisher online versions (see refereed journals above) to biased views of individuals with a specific “agenda”.  Judgement needed!
• Discussion fora (forums)/internet blogs
• Like webpages these can be very variable, but if truly open then rogue information will get critical feedback.

More information:

• Nedelina Tchangalova, What is a "Good" Source? Determining the Validity of Evidence, University of Maryland, 27 May 2014.
• Roger Pierce, Chapter 7 Evaluating Information: Validity, Reliability, Accuracy, Triangulation, in: Research Methods in Politics: a practical guide, Sage Publications, London, April 2008, pp 79-99.  ISBN: 978-1-412-93551-7.