Psych 12 Inquizitive chp 11

elect the research design that is the most susceptible to a maturation threat.

(graph that is the short, one line)

Select the graph that shows data with high within-groups variability.

(one with the biggest wrror bars)

Match each threat to internal validity to the corresponding scenario.

A graduate student predicts that people eating sweets will be friendlier than people eating healthy foods. She has one group of participants eat donuts and interact with one another. She has another group of participants eat carrot sticks and interact with one another. She codes each participant's level of friendliness. observer bias On Monday, an instructor has his class sit in chairs for 2 minutes before completing a reading quiz. On Wednesday, he has the same class do 2 minutes of jumping jacks before completing the same reading quiz that they took on Monday. testing threat Initially, raters are quite strict in their ratings of prosocial behavior in videotapes of a preschool class, but after 3 hours of rating, their criteria become more lenient. instrumentation threat

Which of the following are factors that can contribute to a null effect in a study?

Factor(s) situation noise floor effect weak manipulation Not Factor(s) too much power large sample size

Which of the following are obscuring factors that can be detected with a manipulation check?

Obscuring Factor(s) floor effects weak manipulations ceiling effects Not Obscuring Factor(s) situation noise individual differences

Lucia is interested in studying discrimination in hiring. She designs an experiment in which participants take the role of an employer looking at job candidates for a specific position. Each participant is given two very similar résumés (one for a candidate with a stereotypically female name and one for a candidate with a stereotypically male name) and is then asked to rate the suitability of each candidate for a job. Lucia finds no difference in participants' ratings of male and female candidates. Lucia should be most concerned about ____ in her study. She should consider using ___ with two different groups of participants to address this threat.

demand characteristicxs, a double-blind study

Power increases with a ____ sample. The results of a study with this type of sample would have a ___ CI and would be more likely to be ____ in future studies.

larger, narrow, replicated

Match each threat to the appropriate prevention method.

rempve participant scores from the pretest attrition threat use a comparison group history threat maturation threat regression threat use a posttest-only design instrumentation threat

Label each issue with the solution that would best prevent within-groups variability from obscuring group differences.

situation noise experimental control measurement error more measurements reliable, precise scales individual differences within-groups design

The blue dots in these figures refer to participants in a one-group, pretest/posttest study who dropped out after the pretest (Time 1). Select the figure that depicts a potential attrition threat to internal validity.

(blue dots on left top)

Select the figure that depicts results with more noise.

(dots not touching)

Researchers ran a study on the efficacy of a Go Green campaign designed to encourage students to use less electricity. Select the figure that indicates there was a history threat in the study.

(graoh with lines parallel to each pther)

Dr. Okafor ran a study on the efficacy of the therapy sessions he designed to treat depression. Select the figure that indicates there was a regression threat in his study.

(graph where the lines dont touch)

All else being equal, which of the following are methods that can help increase power in a study?

Method(s) using a within-groups design increasing sample size Not Method(s) using an independent-groups design adding situation noise

Samira finds these results in her study on binge-watching TV and relationship quality: d = −0.13, 95% CI [−.30, .40]. Her variables had good construct validity and she had an adequate sample size. What should Samira do based on the results of her study?

Samira should conclude that there trule is no significant effect and revise her theory

Which of the following validities are threatened by observer bias in an experiment?

Correct Answer(s) construct validity internal validity Incorrect Answer(s) external validity statistical validity

Some threats to internal validity can be addressed simply by including a comparison group, whereas other threats to internal validity can occur even in studies with a comparison group. The inclusion of a comparison group would help to avoid which of the following threats to internal validity?

Avoided Threat(s) maturation threat history threat regression to the mean Not Avoided Threat(s) observer bias demand characteristics

Which of the following strategies are potential ways to prevent individual differences from obscuring group differences?

Correct Answer(s) use a within-groups design increase the number of participants Incorrect Answer(s) use an independent-groups design use validated scales

Which of the following strategies are potential ways to avoid testing threats?

Correct Answer(s) use alternative forms of the test add a comparison group use a posttest-only design Incorrect Answer(s) use a masked design remove participant scores from the pretest

Match each threat to internal validity to the corresponding scenario.

Darnell has his participants look through fashion magazines and then rate their level of body satisfaction. His participants all rate lower satisfaction with their bodies after looking at the magazines. demand characteristics Jahlil wants to find out whether his new self-esteem intervention is effective. One group gets his new intervention, and another group gets a friendly conversation with Jahlil. At the end, he finds that both groups have a boost in self-esteem. placebo effect Jennie creates a new healthy eating seminar. She asks her participants whether they would like to sign up for her new seminar or receive a pamphlet instead. At the end of her study, she finds that the seminar group reports healthier eating habits than the pamphlet group. selection effect Wanda guesses that older children will be more likely to share than younger children. She observes the older children on the playground more closely and notices they do share at a high rate. observer bias

There are several threats that specifically apply to one-group, pretest/posttest experiments. Match each threat to the correct definition

More participants from one group or condition decline to continue participating than from another. attrition threat Participant behavior changes spontaneously over time. maturation threat Participants' future performance is changed because of their interaction with a measure. testing threat Participants' responses are altered by an event outside the control or interest of the study. history threat Extreme scores gravitate back toward average. regression threat The way the researcher measures a variable changes over the course of an experiment. instrumentation threat

There are several threats that specifically apply to one-group, pretest/posttest experiments. Match each threat to the example that best represents it.

Observers code social behavior as less friendly over time. instrumentation threat A large clearance sale takes place during a study on shopping behavior. history threat The three healthiest participants withdraw from a study on metabolic syndrome. attrition threat Participants change their answers on a racism scale after seeing it a second time. testing threat Students in a study on grade performance naturally improve their grades during the study. maturation threat Participants show very high stress scores on the pretest and returned to average on the posttest. regression threat

Professor Zhao wants to test the effectiveness of review sessions on test performance. He randomly assigns the students in his 50-student Introduction to Psychology class to one of two review sessions, each being taught with a different technique. Identify the problem that is most likely causing a null effect in each scenario that might happen in Professor Zhao's study.

Professor Zhao measures the effectiveness of the review sessions with pass/fail categories. He finds that there is no difference between the students in the two review sessions. insensitive measure All 50 students get all 10 test questions incorrect, regardless of the review session they are in. floor effect All 50 students get all 10 test questions correct, regardless of the review session they are in. ceiling effect The review sessions are different in that one is held in-person and the other is held through video conferencing, although they both cover the same content. weak manipulation

Dr. Tran wants to examine the effectiveness of group therapy sessions on drinking behavior. She recruits college students as her participants and randomizes the participants into two groups: a structured-session group and an unstructured-session group. The structured-session group attends 10 sessions that Dr. Tran facilitates. The unstructured-session group attends 10 sessions that members of the group facilitate. Match each threat to internal validity to the corresponding scenario that might happen in Dr. Tran's study.

Several participants in the structured group stop attending after just a couple of sessions, while all members of the unstructured group continue to attend their sessions regularly. selection-attrition threat When Dr. Tran measures drinking behavior in the last week of the sessions, all of the students in the unstructured group have an exam coming up, while the students in the structured group do not. selection-history threat On the first day of the sessions, all of the participants state that they participate in binge drinking 7 days a week. At the end of the study, all of the participants report a significant reduction in drinking. regression threat

Feliciano is using a pretest/posttest design to conduct an experiment on improving children's handwriting, employing two different techniques of improving handwriting and a control condition. In the results, the two groups who receive the treatment don't show any difference from each other. Feliciano believes that there is a difference but that his 3-point assessment scale of handwriting cannot detect it. Identify the true and false statements about Feliciano's study.

True Statement(s) Feliciano is most concerned about using an insensitive measure. To address his concern, Feliciano should use a scale with more levels for his dependent variable. False Statement(s) To address his concern, Feliciano should increase his sample size. To address his concern, Feliciano should use a manipulation check for his independent variable. Feliciano is most concerned about measurement error.

Identify the true and false statements about threats to internal validity in one-group, pretest/posttest designs.

True Statement(s) If participants withdraw from a study in an unsystematic way, there is likely no attrition threat. A regression threat can produce a significant result that does not actually exist in the population. False Statement(s) A study typically has only one threat to internal validity. To prevent a history threat, the comparison group should be studied at a different time or in a different location than the treatment group.

Identify the true and false statements about null effects.

True Statement(s) If there is not enough between-groups difference, it can result in a null effect. Null effects can occur in any experiment. False Statement(s) Decreases in within-groups variability can lead to a null effect. Researchers rarely find null effects in experiments.

Jared wants to examine whether mindfulness training can increase concentration. He begins with a concentration task and finds that on average his participants can concentrate for only 30 seconds. He then gives the participants mindfulness training over the course of 2 weeks and finds that their average score improves significantly to 30 minutes on the same concentration task. Identify the true and false statements about Jared's study.

True Statement(s) Jared should include a comparison group to address the threat in his study. Jared's study has a regression threat. False Statement(s) Jared's study has an instrumentation threat. Jared should use a masked design to address the threat in his study.

Identify the true and false statements about null effects.

True Statement(s) Measurement error causes null effects because it leads to high within-groups variability. It is possible for researchers to find null effects because the independent variable really does not cause a significant difference. Studies with null effects should be replicated and included in meta-analyses. False Statement(s) Null effects only happen in posttest-only designs. Researchers should not report null effects because they are not informative.

Identify the true and false statements about the placebo effect.

True Statement(s) The placebo effect can be addressed by including a control group that does not receive anything. The placebo effect can be addressed by using a double-blind placebo control study. Placebos have an effect because people believe in the effectiveness of the treatment they think they are receiving. False Statement(s) The placebo effect can be addressed by randomly assigning participants to conditions. Patients receiving a placebo do not experience relief in their symptoms.

On the first exam in an Introductory Psychology class, the grades are lower than Professor Mutola expected. She suspects that multitasking is to blame. She bans computers and smart phones from her class between the first and second exams. When she compares the two sets of exam scores, she finds a significant improvement on the second exam. Match each threat to internal validity to the corresponding scenario that might happen in Professor Mutola's study.

When rechecking her data, Professor Mutola finds that the five students with the lowest scores on the first exam dropped the class. attrition threat Professor Mutola notes that every semester students always do better on the second exam because they are more used to the class. maturation threat Professor Mutola looks back over the second exam and discovers it was an easier exam. instrumentation threat

Frances decides to conduct a second study on concreteness and memory in a laboratory setting. She creates a list of 12 concrete items (e.g., pencil and table) and a list of 12 abstract items (e.g., justice and freedom). Participants view each word for 1 second and then recall them in order. The study shows a null effect, and almost all the participants remembered all the words on both lists. Frances' study has a null effect likely because of ___, which led to ___ variability. To eliminate this problem, Frances should consider making the task ____.

a ceiling effect, not enoug between-groups, more difficult

Amodhi is planning an experiment to examine whether reading to children increases their vocabulary size. She plans to measure the vocabulary size of a group of 18-month-old children, read to them three times a week for 3 months, and then measure their vocabulary size again. Based on her design, Amodhi should be most concerned about ___ . She can address this issue by adding.

a maturation threat, a comparison group

Antonio is studying how different pamphlets promoting a local charity might increase volunteer behavior in high school students. He creates one pamphlet that shows students having fun and being social while volunteering, and another that discusses the benefits volunteering has for college applications and future careers. Antonio has participants read one pamphlet or the other and then fill out a questionnaire about their intentions for volunteering in the future. Antonio's questionnaire asks participants to rate how likely they are to volunteer in the future on a scale of 1 ("I will not volunteer at all") to 5 ("I will likely volunteer in the future"). Antonio finds that both groups score an average of 4.8 on his measure. What problem is most likely causing a null effect in Antonio's study?

celining effect

Zion is investigating the effectiveness of his summer math tutoring program. He randomly assigns elementary school students to a tutoring group, which receives the math tutoring program 3 days a week during the entire break, or a self-study group, which receives a sample of math materials without a tutor. At the end of the summer, all of the students take the same math test with a possible score of 0 to 100. The students in the tutoring group are proctored by a strict and intimidating teacher, while the students in the self-study group are proctored by a friendly and approachable teacher. Zion finds these results: d = 0.15, 95% CI [−.30, .45]. What is the most likely explanation for Zion's results?

design confounds acting in reverse

A city in California has asked Professor Rodriguez to conduct an experiment on earthquake preparedness. Professor Rodriguez will assess the preparedness of a random sample of residents in the city, and then the city will mail out an annual brochure on earthquake safety. Then, 2 weeks later, he will again assess the preparedness of those residents. Right after the brochures are mailed, a large earthquake is reported in Japan. Which threat to internal validity is present in Professor Rodriguez's experiment?

history threat

Amodhi is planning an experiment to examine whether reading to children increases their vocabulary size. She plans to measure the vocabulary size of a group of 18-month-old children, read to them three times a week for 3 months, and then measure their vocabulary size again. Based on her design, Amodhi should be most concerned about ___ . She can address this issue by adding ___

maturation threat, a comparison group

Null effects can be caused by excessive amounts of unsystematic variance, or ____. This within-groups variability can be caused by a dependent variable with poor reliability or by faulty data collection, which is referred to asn ____. It can also be caused by ___ if variations in participants' characteristics obscure changes brought on by the manipulation. Finally, outside factors in the experimental setting can influence participants, otherwise referred to as ___.

noise, measurement error, individual differences, situation noise

If a researcher determines that the independent variable makes no significant difference in the dependent variable, they are concluding a(n) ___ . This could either be the truth (the variables really are not related) or be due to design flaws in the experiment. There are several design flaws that may produce such a result. A(n) ___ can occur when the change in the independent variable is not strong enough to affect the dependent variable. Or the dependent variable might not be responsive enough to detect change from the independent variable; in other words, it could be a(n) ____. Additionally, scores from the dependent variable can spontaneously cluster near the top of possible scores, known as the ____ , or near the bottom of possible scores, known as the ____Press Space to openplacebo effectfloor effectinsensitive measureinstrumentation threatceiling effectnull effectweak manipulationdemand characteristics—these phenomena can make covariance undetectable.

null effect. weak manipulation, insensitive measure, ceiling effect, floor effect

The influence of a researcher's own expectations on how they view outcomes in an experiment is called ___ Press Space to openobserver biasdouble-blind studymasked designplacebo effectdouble-blind placebo control study. This can be prevented by making sure that researchers are unaware of which participants are in which conditions, called a(n) ___ . To further reduce this issue, the conditions can sometimes be unknown to both the experimenter and the participant, called a(n) ___.

observer bias, masled design, double-blind study

Jermaine is curious whether the way students take notes affects their academic ability. He recruits two groups of students: one group of high achievers and one group of low achievers. He then asks both groups to take notes in the exact same way to see how it will affect their scores. During the study, several students in the low-achieving group drop out from the study, as they find the notetaking task difficult. At the end of the study, the results for each group are similar. What threat to internal validity may be present in Jermaine's experiment?

selection-attrition threat

Frances is conducting a study on concreteness and memory in her dorm room with several of her hallmates. She creates a list of 12 concrete items (e.g., pencil and table) and a list of 12 abstract items (e.g., justice and freedom). Her hallmates view each word for 1 second and then recall them in order. Contrary to Frances' prediction, the study shows a null effect. The study has a null effect likely because of ____, which led to ___ variability.

situation noise, too much within-groups

Candice has created an intervention to find out whether using imagination increases children's spatial reasoning abilities. She randomly recruits kindergarteners from city schools and pretests them with a spatial reasoning task. After a week of her intervention, she measures the children's spatial reasoning again using the same survey. All the children score better on the assessment the second time compared with the first. What threat to internal validity may be present in Candice's experiment?

testing threat

Kunene creates an experiment to investigate whether viewing pictures on different types of social media sites causes people to feel more or less social. She has participants look at pictures on a website with either a Facebook logo or an Instagram logo, but everything else about the website is the same. Kunene measures sociability using a questionnaire that asks participants to rate themselves on a scale of 1 to 10 in response to several questions, such as "How interested are you in meeting other people right now?" and "How interested are you in talking to your friends right now?" Kunene finds that both groups have sociability averages around 6. What problem is most likely causing a null effect in Kunene's study?

weak manipulation