inquizitive 5

Identify the true statements about the placebo effect.

- 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. - The placebo effect can be addressed by including a control group that does not receive anything.

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

- use a masked design - remove participant scores from the pretest

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.

This result shows that the Go Green campaign did not work, since both the group receiving the campaign and the group not receiving the campaign reduced their electricity use in November due to a history threat. The external event that caused the history threat was the change of seasons, which prompted both groups to use less air conditioning and, therefore, less electricity. both lines together decreasing

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 With an instrumentation threat, it is the instrumentation that changes rather than the dependent variable.

Match each threat to internal validity to the corresponding scenario. 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 The raters, who are the measuring instrument, change over the course of 3 hours.

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

- add a comparison group - use alternative forms of the test - use a posttest-only design

A double-blind study is

a study in which neither the researcher nor the participants know which group the participants are in.

Observer bias occurs

when researchers' expectations influence how they interpret the results.

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. Professor Mutola looks back over the second exam and discovers it was an easier exam.

instrumentation threat

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. Professor Mutola notes that every semester students always do better on the second exam because they are more used to the class.

maturation threat

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

one group - measure DV - IV level 1 - measure on DV

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

- A regression threat can produce a significant result that does not actually exist in the population. - If participants withdraw from a study in an unsystematic way, there is likely no attrition threat.

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 statements about Jared's study.

- Jared's study has a regression threat. --> Jared's participants perform unusually poorly on the pretest, so it is likely to regress upward on the posttest, even without training. - Jared should include a comparison group to address the threat in his study. -->A comparison group would allow Jared to compare the pattern of results for a group that receives the mindfulness training and a group that does not receive the training.

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 false statements about Jared's study.

- Jared's study has an instrumentation threat. -->Because the pretest and posttest involve the same concentration task, it is unlikely that Jared has an instrumentation threat. - Jared should use a masked design to address the threat in his study. -->It doesn't seem likely that the results of the study are due to demand characteristics or observer bias, so a masked design would not address the specific threat in Jared's study.

Identify the false statements about the placebo effect.

- Patients receiving a placebo do not experience relief in their symptoms. - The placebo effect can be addressed by randomly assigning participants to conditions.

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

- To prevent a history threat, the comparison group should be studied at a different time or in a different location than the treatment group. - A study typically has only one threat to internal validity.

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

- construct validity - internal validity

use a comparison group Match each threat to the appropriate prevention method.

- history threat - regression threat - maturation threat

Match each threat to the appropriate prevention method. use a posttest-only design

- instrumentation threat --> An instrument cannot change over time if it is used only once.

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?

- maturation threat - history threat - regression to the mean

Match each threat to the appropriate prevention method. use a comparison group

- maturation threat --> With a comparison group, you can see whether a manipulation is successful in spite of the maturation threat. - history threat --> As long as both groups experience the same event, you can look for other differences between them that the experimental manipulation might explain. - regression threat --> A comparison group allows you to see whether scores are returning to normal or truly being affected by the independent variable.

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.

A regression threat is possible in this result because only the therapy group started out with an extreme score and showed a change over time, while the control group started out with a less extreme score and maintained this score over time. The reduction in depression in the therapy group could possibly have been due to regression to the mean rather than the effectiveness of the therapy.

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.

When the dropouts' scores are extreme (at the high or low end of the group), the group mean can change significantly in the posttest. When this is the case, it can be difficult to determine whether the change in scores at the posttest is truly due to the intervention or simply due to the dropouts. m = 5.71 to m = 4.32

A masked or blind design is

a design in which participants know which group they are in, but the researchers do not.

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

remove participant scores from the pretest Match each threat to the appropriate prevention method.

attrition threat

There are several threats that specifically apply to one-group, pretest/posttest experiments. Match each threat to the example that best represents it. The three healthiest participants withdraw from a study on metabolic syndrome.

attrition threat Because the participants who withdraw are not random in all characteristics, their withdrawal presents a threat to internal validity.

More participants from one group or condition decline to continue participating than from another.

attrition threat Participants who do not complete all parts of a study should be thoroughly scrutinized or removed.

Match each threat to the appropriate prevention method. remove participant scores from the pretest

attrition threat --> By removing the pretest scores of participants who leave a study in the middle, you can ensure that the data will not be affected by the lack of their posttest scores.

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 Darnell's participants may guess the purpose of the study (examining the effect of magazines on body satisfaction) and change their behavior accordingly.

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 characteristics ------- a double blind study

Participants' responses are altered by an event outside the control or interest of the study.

history threat Experiments are not conducted in a vacuum; events outside of the study can often influence behavior.

There are several threats that specifically apply to one-group, pretest/posttest experiments. Match each threat to the example that best represents it. A large clearance sale takes place during a study on shopping behavior.

history threat The clearance sale would likely influence participants' shopping behavior to be different than it might have been without the sale.

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 The earthquake is an external or "historical" event that affects everyone in the study. Therefore, it will be difficult for Professor Rodriguez to determine whether the participants' earthquake preparedness is due to the effect of the brochure or to concern caused by the earthquake in Japan.

use a posttest-only design Match each threat to the appropriate prevention method.

instrumentation threat

The way the researcher measures a variable changes over the course of an experiment.

instrumentation threat When coding behavioral data, researchers can sometimes inadvertently change how they code certain behaviors.

Participant behavior changes spontaneously over time.

maturation threat Maturation threat can be prevented by using comparison groups to control for any spontaneous changes.

There are several threats that specifically apply to one-group, pretest/posttest experiments. Match each threat to the example that best represents it. Students in a study on grade performance naturally improve their grades during the study.

maturation threat Participant behavior is not static and can often change throughout a study, regardless of the manipulation.

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 - Because children rapidly develop language skills at this age, Amodhi will not be able to know whether her intervention is truly effective or whether the children's vocabularies simply increase on their own. Comparison group - The best way to address the potential issue in Amodhi's study would be to have a comparison group that does not receive the reading intervention. If the treatment group has better vocabulary than the comparison group, then Amodhi will know that her intervention is effective.

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 Because the graduate student knows which participants are in the sweets group and which are in the healthy food group, her expectations could affect her ratings of their friendliness.

Match each threat to internal validity to the corresponding scenario. 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 Wanda's expectation of the study results makes her pay more attention to the older children. The results of the study may be due to Wanda's biased observation rather than actual group differences.

The influence of a researcher's own expectations on how they view outcomes in an experiment is called ______ ________. 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 masked design double blind study

Match each threat to internal validity to the corresponding scenario. 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 In this case, the placebo (friendly conversation) actually has an effect on the participants' self-esteem.

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. 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

Extreme scores gravitate back toward average.

regression threat Researchers should compare participant scores at various times within the experiment while also comparing them with average scores.

There are several threats that specifically apply to one-group, pretest/posttest experiments. Match each threat to the example that best represents it. Participants show very high stress scores on the pretest and returned to average on the posttest.

regression threat Because the original scores are extreme, it is likely they would return to average regardless of the experimental manipulations.

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 Even though this study design has two groups (as opposed to a one-group, pretest/posttest design), it is still susceptible to a selection-attrition threat because members of just one type dropped out from the study.

Match each threat to internal validity to the corresponding scenario. 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 Jennie's participants can choose which condition they want to be in, so she can't be sure whether her seminar is effective or whether participants who sign up for the seminar are particularly interested in healthy eating behaviors.

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

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. 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

There are several threats that specifically apply to one-group, pretest/posttest experiments. Match each threat to the example that best represents it. Participants change their answers on a racism scale after seeing it a second time.

testing threat In this example, the racism scale is changing how the participants behave.

Participants' future performance is changed because of their interaction with a measure.

testing threat Measures must be reviewed carefully to be certain they do not have lasting effects on participants.

Match each threat to internal validity to the corresponding scenario. 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 Because the students are taking the same quiz just 2 days later, they might do better because of their previous experience with it.

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 - Because there is no comparison group, it is difficult to say whether the children improve due to the intervention or whether they simply become better at the spatial reasoning task over time.