PSYCHOLOGY 255 STUDY EXAMS GUIDE ALL
QUESTIONS AND ANSWERS SURE A+
✔✔What is an independent-groups design - ✔✔Different participants are placed in each
condition.
✔✔What is a within-groups design - ✔✔The same participants experience all
conditions.
✔✔What is a posttest-only design - ✔✔Only measuring outcomes after treatment.
✔✔What is a pretest/posttest design - ✔✔Measuring participants before and after
treatment.
✔✔What is a repeated-measures design - ✔✔A within-groups design measuring
participants multiple times.
✔✔What are advantages of within-groups designs - ✔✔Fewer participants are needed
and participant differences are controlled.
✔✔What are disadvantages of within-groups designs - ✔✔Order effects may occur.
, ✔✔What are order effects - ✔✔Effects caused by the order participants experience
conditions.
✔✔What is construct validity in experiments - ✔✔How well variables are manipulated
and measured.
✔✔What is internal validity - ✔✔The extent to which the IV caused the DV.
✔✔What is external validity - ✔✔The extent results generalize to other settings or
people.
✔✔What is a confounding variable - ✔✔An alternative explanation for the results.
✔✔What is a history threat - ✔✔An outside event affects participants during the study.
✔✔What is maturation - ✔✔Natural participant changes over time.
✔✔What is regression to the mean - ✔✔Extreme scores becoming more average over
time.
✔✔What is attrition - ✔✔Participants dropping out of a study.
✔✔What are testing effects - ✔✔When taking a test changes later performance.
✔✔What is instrumentation - ✔✔Changes in measurement tools over time.
✔✔What is a null effect - ✔✔No significant difference between groups.
✔✔Why might a null effect occur - ✔✔Weak manipulations, poor measurements, or high
variability.
✔✔What are obscuring variables - ✔✔Variables increasing noise and hiding real
effects.
✔✔What is statistical power - ✔✔The ability to detect a real effect.
✔✔How can researchers increase statistical power - ✔✔Use larger samples, stronger
manipulations, and reduce variability.
✔✔Why should null findings be reported - ✔✔For transparency and scientific accuracy.
✔✔What is a factorial design - ✔✔An experiment with two or more independent
variables.
QUESTIONS AND ANSWERS SURE A+
✔✔What is an independent-groups design - ✔✔Different participants are placed in each
condition.
✔✔What is a within-groups design - ✔✔The same participants experience all
conditions.
✔✔What is a posttest-only design - ✔✔Only measuring outcomes after treatment.
✔✔What is a pretest/posttest design - ✔✔Measuring participants before and after
treatment.
✔✔What is a repeated-measures design - ✔✔A within-groups design measuring
participants multiple times.
✔✔What are advantages of within-groups designs - ✔✔Fewer participants are needed
and participant differences are controlled.
✔✔What are disadvantages of within-groups designs - ✔✔Order effects may occur.
, ✔✔What are order effects - ✔✔Effects caused by the order participants experience
conditions.
✔✔What is construct validity in experiments - ✔✔How well variables are manipulated
and measured.
✔✔What is internal validity - ✔✔The extent to which the IV caused the DV.
✔✔What is external validity - ✔✔The extent results generalize to other settings or
people.
✔✔What is a confounding variable - ✔✔An alternative explanation for the results.
✔✔What is a history threat - ✔✔An outside event affects participants during the study.
✔✔What is maturation - ✔✔Natural participant changes over time.
✔✔What is regression to the mean - ✔✔Extreme scores becoming more average over
time.
✔✔What is attrition - ✔✔Participants dropping out of a study.
✔✔What are testing effects - ✔✔When taking a test changes later performance.
✔✔What is instrumentation - ✔✔Changes in measurement tools over time.
✔✔What is a null effect - ✔✔No significant difference between groups.
✔✔Why might a null effect occur - ✔✔Weak manipulations, poor measurements, or high
variability.
✔✔What are obscuring variables - ✔✔Variables increasing noise and hiding real
effects.
✔✔What is statistical power - ✔✔The ability to detect a real effect.
✔✔How can researchers increase statistical power - ✔✔Use larger samples, stronger
manipulations, and reduce variability.
✔✔Why should null findings be reported - ✔✔For transparency and scientific accuracy.
✔✔What is a factorial design - ✔✔An experiment with two or more independent
variables.
