Extraneous Variables and Standardization

Research Methods — Week 9. From the comprehensive notes.

What is an extraneous variable?

A factor outside the intended design that influences the relationship being studied.

How could room temperature confound a proximity experiment?

If treatment groups are cold and controls comfortable, temperature rather than seating may explain differences in social closeness.

Why standardize experimental procedures?

Keeping instructions, settings, timing, and researcher behaviour consistent reduces alternative explanations.

How can researcher blinding help?

Not knowing participants’ conditions reduces the chance that expectations influence their treatment.

What is an attrition or mortality threat?

Participants leave a study, potentially changing the composition or comparability of the groups.

Does a controlled experiment automatically generalize to other settings?

No. Strong internal validity does not by itself establish external validity.