Psychology: Research Methods: Experimental Design and Ethics
Designing fair studies and protecting participants
Psychology: Research Methods: Experimental Design and Ethics
Designing fair studies and protecting participants
Psychology - Grade 9-12
- 1
A psychologist wants to test whether listening to classical music while studying improves quiz scores. Students are assigned to study with classical music or in silence, then take the same quiz. Identify the independent variable and the dependent variable.
The independent variable is what the researcher changes. The dependent variable is what the researcher measures.
The independent variable is the study condition, which is listening to classical music or studying in silence. The dependent variable is the quiz score because it is the outcome being measured. - 2
Write an operational definition for the variable stress in a study about test preparation.
Stress could be operationally defined as a participant's score on a 10-item stress survey completed right before the test. This makes stress measurable and consistent across participants. - 3
A researcher claims that a new phone app reduces anxiety. Describe a simple experimental design that could test this claim, including a control group and an experimental group.
A strong design compares groups that are treated the same except for the independent variable.
The researcher could randomly assign participants to use the anxiety-reduction app for two weeks or to use a neutral app for the same amount of time. The experimental group would use the anxiety app, the control group would use the neutral app, and both groups would complete the same anxiety measure before and after the study. - 4
Explain the difference between random sampling and random assignment in psychological research.
Sampling is about who enters the study. Assignment is about which group each participant enters.
Random sampling is how researchers select participants from a larger population, and it helps make the sample more representative. Random assignment is how researchers place participants into different study groups, and it helps reduce preexisting differences between groups. - 5
A study finds that students who sleep more have higher grades. The researcher concludes that sleep causes higher grades. Explain why this conclusion may not be justified.
The conclusion may not be justified because the study only shows a relationship between sleep and grades. Other variables, such as study habits, stress, health, or family support, could affect both sleep and grades, so the study does not prove cause and effect. - 6
In a medication study, one group receives the actual medication and another group receives a sugar pill that looks the same. What is the purpose of the sugar pill?
A placebo looks like a treatment but does not contain the active ingredient being tested.
The sugar pill is a placebo. It helps researchers determine whether changes are caused by the actual medication or by participants' expectations about receiving treatment. - 7
A researcher studying memory gives one class a memory strategy lesson and another class no lesson. The memory strategy class is taught by a highly enthusiastic teacher, while the no-lesson class is taught by a substitute teacher. Identify a possible confounding variable and explain why it matters.
A possible confounding variable is the teacher's enthusiasm or teaching quality. It matters because differences in memory scores might be caused by the teacher rather than by the memory strategy lesson. - 8
A study is single-blind. What does this usually mean, and why can it improve an experiment?
Think about how knowing you received a treatment might change how you report your symptoms.
A single-blind study usually means that participants do not know which treatment or condition they are receiving. This can improve the experiment by reducing the effect of participants' expectations on their behavior or responses. - 9
A double-blind study is used to test a new therapy for depression. Explain what double-blind means in this context.
Double-blind means that neither the participants nor the researchers interacting with them know who is receiving the new therapy and who is in the comparison condition during the study. This helps reduce bias from both participant expectations and researcher behavior. - 10
Read this consent statement: You will complete a mood survey and watch a short video. You may stop at any time without penalty. Your responses will be kept confidential. Identify two ethical protections included in the statement.
Look for language about choice, risk, privacy, and what participants will experience.
Two ethical protections are the right to withdraw at any time without penalty and confidentiality of responses. The statement also gives participants information about what they will do in the study. - 11
A researcher tells participants they are taking a logic test, but the real purpose is to study how people react to failure. Participants are given impossible questions so they will feel frustrated. What ethical issue is involved, and what should the researcher do after the study?
The ethical issue is deception because participants are not told the true purpose of the study. After the study, the researcher should debrief participants by explaining the real purpose, why deception was used, and offering support if the task caused distress. - 12
Why do many psychology studies need review by an Institutional Review Board or ethics committee before data collection begins?
The review happens before the study to prevent ethical problems rather than only responding after harm occurs.
An Institutional Review Board or ethics committee reviews studies to protect participants from unnecessary harm. It checks that risks are reasonable, consent procedures are clear, privacy is protected, and the study follows ethical standards. - 13
A psychologist wants to study stress in middle school students by collecting detailed information about family conflict. Name one extra ethical concern when research involves minors and explain how it can be addressed.
One extra ethical concern is that minors may not be able to give full legal consent on their own. This can be addressed by obtaining parent or guardian consent, getting the student's assent, protecting privacy, and making sure participation is voluntary. - 14
A table shows average stress scores after a study: Control group = 7.2, mindfulness group = 5.1, exercise group = 5.4. Based on these results, which group had the lowest average stress, and what cautious conclusion could be made?
Lower stress scores mean less reported stress, but one set of averages is not enough for a strong conclusion by itself.
The mindfulness group had the lowest average stress score at 5.1. A cautious conclusion is that mindfulness may reduce stress compared with the control condition, but the researcher should also consider sample size, random assignment, statistical significance, and possible confounds. - 15
Design an ethical study to test whether taking short breaks during homework improves concentration. Include the independent variable, dependent variable, one control, and one ethical protection.
An ethical study could randomly assign students to take short scheduled breaks during homework or to complete homework without scheduled breaks for the same total work period. The independent variable is the break condition, and the dependent variable could be concentration measured by number of correctly completed problems or a concentration rating. One control is giving both groups the same homework and time period. One ethical protection is informed consent with the right to stop participating at any time.