How do you know whether your intervention had an effect.

Study design 101 brief overview of several designs (randomized control trial, cohort, case control). 2011.

Experimental Design and Some Threats to Experimental Validity: A Primer Skidmore, Susan. Online Submission, Paper presented at the Annual Meeting of the Southwest Educational Research Association (New Orleans, LA, Feb 6, 2008)

Research Methods Knowledge Base, chapter on design last updated in 2006.

Allpsych on line texts the research methods text is mainly about design, see chapters 5 and 6 especially. Also has an on line text on stats.

When to Use a Randomized Controlled Trial and When Not to April 2013, from Dr. Bernadette Wright, Meaningful Evidence. This paper is also available as pdf on her resource page.

Quasi-Experimental Evaluation Kristin Anderson Moore, Ph.D. 2008.

Research Design Lessons lectures in word. Dr. Karl Wuensch, last revised 2016

Anol Bhattacherjee Social Science Research: Principles, Methods, and Practices from 2012. On line text book, complete book. Chapters 5 and 10 are about research design, but other chapters are useful too.

How Random Must Random Assignment Be in Random Assignment Experiments? by Paul Gustafson, 2003, "This technical paper reviews options for different approaches to randomization used in experimental studies that measure program impacts"

Quasi-Experimental Design and Methods Howard White; Shagun Sabarwal, 2014.

Also see their methodological briefs

The Core Analytics of Randomized Experiments for Social Research, by Howard S. Bloom, 2006

Tom Knapp's books, articles on various statistical topics, including percentages, statistical testing, reliability. One book, Quantitative Research Methods (2016) explains some aspects of design. Some of these books are also available here

Research Design This is in an evaluation module, from Lynsie Ranker, William DeJong, Rob Schadt, Boston University School of Public Health. 2015.

Threats to Validity

Internal and External Validity This is in an evaluation module, from Lynsie Ranker, William DeJong, Rob Schadt, Boston University School of Public Health. 2015.

Basic Threats to Internal Validity Jason T. Newsom PhD, Spring 2013. (Also mentions, briefly, self selection bias)

Internal Validity Basics of Research for the Health Professions. Linda L. Wright & David A. Lake, includes a short description of selection bias. Not sure of the date.

What researchers mean by... validity and reliability. from Institute for Work and Health. 2016.

Threat to validity overview of threats to validity. See part 1. Dr. David Polson, last modified 2016

Nursing Resources: Threats to Validity of Research Designs nice overview. Also see the page on types of designs

The Threats to Validity page above says they got information from this page Threats to Validity, Chong-ho Yu, Associate Professor of Psychology at Azusa Pacific University. 2018.

Selection Bias

What researchers mean by... selection bias At Work, Issue 76, Spring 2014: Institute for Work & Health, Toronto

Avoiding Bias in Observational Studies. Part 8 in a Series of Articles on Evaluation of Scientific Publications.

Gaël P Hammer, Jean-Baptist du Prel, Maria Blettner

Controlling for Program Participation Self-Selection Bias. Shawn Bodmann, et al. International Energy Program Evaluation Conference, Chicago, 2013. An example of using propensity scores to try to account for self selection bias. 2013 conference here

Soumerai SB, Starr D, Majumdar SR. How Do You Know Which Health Care Effectiveness Research You Can Trust? A Guide to Study Design for the Perplexed. Prev Chronic Dis 2015;12:150187. DOI: or

Boston University School of Public Health module on bias unclear who the author is. From 2016. Many other modules are here MPH on line learning modules

Last updated and reviewed 2/13/2018