Research methods knowledge base
www.socialresearchmethods.net

Validity and reliability in quantitative research
http://allpsych.com/researchmethods/variablesvalidityreliability.html

A Framework for Assessing the Quality of Qualitative Research
www.nationalschool.gov.uk/policyhub/news_item/qual_framework.asp

Methods@manchester – What is Quality in Qualitative Research?
www.methods.manchester.ac.uk/methods/qualityinquali/index.shtml

e-Source: Chapter 7 'A Reporting Checklist for Observational Studies' by Richard Berk
www.esourceresearch.org