Experiments and Variables
What is the variable that the researcher changes or manipulates?
Independent Variable
What experimental design uses different participants in each condition?
Independent measures design.
What term means that a study produces consistent results?
Reliability.
What ethical guideline means participants should know enough about the study to agree to participate?
Informed consent.
A correlation of r=+0.80 is positive or negative?
Positive.
What is the variable that is measured to determine the effect of the IV?
Dependent Variable
What design uses the same participants in every condition?
Repeated measures design.
What type of validity asks whether a study reflects behavior in a real-life setting?
Ecological Validity.
What ethical right allows a participant to leave a study at any point?
Right to withdraw.
What type of correlation occurs when one variable increases while the other decreases?
Negative correlation.
Researchers compare students studying with music at 8 a.m. with students studying in silence at 2 p.m. What is the problem with this experiment?
Time of day is an uncontrolled/confounding variable because it differs between conditions and could affect performance.
What technique gives every member of the target population an equal chance of being selected?
Random sampling.
Two observers watch the same behavior and record almost identical results. What type of reliability does this demonstrate?
Inter-rater/inter-observer reliability.
Researchers intentionally give participants false information about the true purpose of a study. What ethical issue is this?
Deception.
Why can a correlation not prove causation?
Correlations show an association, but they do not establish which variable causes the other; a third variable could also explain the relationship.
A researcher defines aggression as "the number of times a participant pushes another person during a 10-minute observation." What research concept is being demonstrated?
Operationalization; aggression has been defined in a measurable way.
Participants perform Condition A and then Condition B. They perform better in B because they already practiced the task. What effect has occurred?
Practice effect, which is a type of order effect.
A researcher repeats a study using the exact same standardized procedure and gets similar results. What two research concepts does this demonstrate?
Replicability and reliability.
After using deception, what should researchers do at the end of the study to explain the true purpose?
Debrief participants, explain the true purpose and deception, and address any concerns.
Which measure of central tendency is usually most affected by an extreme score: mean, median, or mode?
Mean. (Average)
A study finds that caffeine improves test performance, but the caffeine group also slept 8 hours while the control group slept only 4. Identify the confounding variable and explain why it is a problem.
Amount of sleep is the confounding variable. Because sleep differs between groups, the researcher cannot know whether caffeine or sleep caused differences in test scores.
Explain one advantage and one disadvantage of a repeated-measures design.
Possible advantage: participant variables are controlled because the same people complete both conditions, and fewer participants are needed.
Possible disadvantage: order effects/demand characteristics can occur.
Explain the difference between reliability and validity. Can a study be reliable but not valid?
Reliability means consistency; validity means whether the study actually measures what it intends to measure/accurately represents the phenomenon being studied.
A psychologist secretly observes students arguing in a school restroom. Identify two possible ethical concerns.
Possible concerns include: privacy, lack of informed consent, deception, and possibly confidentiality depending on ow the information is recorded/reported.
A researcher finds r=-0.92 between hours spent gaming and hours spent studying. Describe the direction and strength of this relationship and explain what the researcher cannot conclude.
It is a very strong negative correlation. As gaming hours increase, studying hours tend to decrease. Researchers cannot conclude that gaming causes students to study less.