Generalization and Research Participation Effects

Research Methods — Week 5. Key concepts from the comprehensive notes.

What is the Hawthorne effect?

People change their behaviour because they know they are being studied.

What is a placebo effect?

Expectations about a treatment influence outcomes independently of the treatment’s specific effect.

What is multiple-treatment interference?

Experiencing one treatment changes responses to another and limits generalization to either alone.

What are active experimenter effects?

A researcher’s expectations are unintentionally communicated in ways that influence participant performance.

What are passive experimenter effects?

Researcher characteristics, such as gender or race, influence participant behaviour.

Why can narrowly specified variables limit external validity?

A particular population, setting, time, or operational definition may not represent other contexts.