Chapter 4: Measurement and Units of Analysis
Explore Psychology. (2019). What is an extraneous variable? Retrieved from https://www.explorepsychology.com/what-is-an-extraneous-variable/
Palys, T., & Atchison, C. (2014). Research decisions: Quantitative, qualitative, and mixed methods approaches (5th ed.). Toronto, Canada: Nelson Education.
Saylor Academy. (2012). Principles of sociological inquiry: Qualitative and quantitative methods. Retrieved from https://www.saylor.org/site/textbooks/Principles%20of%20Sociological%20Inquiry.pdf