During an experiment a researcher decides to assign participants to the experimental and control groups based on their birthdays. The participants are juvenile offenders. Those born from January through June are assigned to the experimental group. The participants born from July through December are assigned to the control group. The experiment involves an assessment of academic achievement on the onset of juvenile delinquency. What type of threat to the external validity of this experiment's re

Question

Quizplus · Accepted Answer

The researcher's decision to assign participants to the experimental and control groups based on their birthdays creates a selection bias. This threat to external validity could impact the generalizability of the results to other populations or situations. Additionally, there is no indication that reactivity is a potential threat in this experiment.

During an Experiment a Researcher Decides to Assign Participants to the Experimental