Unit 1 – Participant Processes

Intro:	One of the most common mistakes is to confuse subject selection and subject assignment or to confuse which relates to which type of validity.
	Participant sampling/selection… Involves who will participate in the study Influences to the population portion of external validity Participant assignment … Involves who will participate in which condition or treatment of the study when Influences the initial equivalence portion of internal validity
Goal:	This exercise will give you practice at identifying “Participant Selection” vs. “Participant Assignment” · Determine if the process described is selection or assignment · Identify the specific validity component involved … o Participant Selection à Population part of External Validity o Participant Assignment à Initial Equivalence part of Internal Validity · Identify if the process will directly influence … o Generalizability/Applicability of the results o Causal Interpretability of the results
	There are three topics in this exercise: Selection Processes – statements of participant selections Assignment Processes – statements of participant assignments Selection Problems – problems with “non-optimal” participant selections Assignment Problems – problems with “non-optimal” assignments
Reading:	The External Validity Lecture (pdf) and the Internal Lecture (pdf) both have useful information in them to help you with this exercise.
Exercise:	Go to the Psyc350 Canvas section, open the Modules & look in “Unit 1 Pink Things” -- complete the exercise titled U1 – Participant Processes Prelude
Due Date:	Please have this done before the next lecture -- the exam will be soon!