Deck 10: More on Experiments: Confounding and Obscuring Variables

Question 1

Regression is especially problematic in which of the following situations?

A) When one group has an extremely low score at pretest
B) When one group has an extremely high score at pretest
C) When the experimental and comparison groups are equal at pretest
D) Both a and b
E) All of the situations above run the risk of regression threats to internal validity

Answer 1

Both a and b

Question 2

Dr.LaGuardia is curious as to whether children in a daycare center will share more after watching an education video on sharing.Immediately before and after the video,he has several undergraduate research assistants code the sharing behavior of a group of 33 four-year-olds.Which of the following would you recommend to her to decrease the threat of instrumentation?

A) Establishing the reliability and validity of her coders at pretest
B) Establishing the reliability and validity of her coders at posttest
C) Using clear coding manuals
D) All of the above should be recommended
E) None of the above should be recommended

Answer 2

All of the above should be recommended

Question 3

A decrease in participants' scores on a measure from pretest to posttest could suggest which of the following threats to internal validity?

A) Regression
B) Maturation
C) Testing
D) Both a and c
E) All of the above

Answer 3

Both a and c

Question 4

Observer bias can threaten which of the following big validities?

A) Internal validity
B) External validity
C) Construct validity
D) Both a and c
E) Both a and b

Question 5

Spontaneous remission in clinical studies is an example of which of the following threats to internal validity?

A) Regression
B) Attrition
C) Observer bias
D) Placebo effects
E) None of the above

Question 6

To be a history threat,the external event must occur:

A) Constantly during the experiment
B) At the beginning of the experiment
C) Systematically, affecting most members of the group
D) Intentionally, affecting most members of the group
E) Because of a participant's behavior

Question 7

RESEARCH STUDY 10.1
In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam.
Refer to Research Study 10.1 above to answer the following question. The study described above is an example of which of the following?

A) A one-group, pretest/posttest design
B) A null effect
C) A double-blind study
D) Observer bias
E) None of the above

Question 8

Which of the following is true of instrumentation threats?

A) They are the same as testing threats.
B) They occur only when using mechanical instruments (e.g., blood pressure cuffs, scales).
C) They can be avoided with one-group, pretest/posttest designs.
D) They are only problematic in observational research.
E) None of the above are true.

Question 9

The addition of a comparison group can address all of the following threats to internal validity EXCEPT:

A) History
B) Maturation
C) Regression
D) Attrition
E) A comparison group can address all of these threats to internal validity

Question 10

RESEARCH STUDY 10.1
In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam.
Refer to Research Study 10.1 above to answer the following question. Imagine that in Dr.Schulenberg's study,he notes that all of the students do extremely well on the midterm exam.When he looks at the results of the final exam,he notices that all the students' exam scores went down.Given this information,which of the following threats might be present in his study?

A) Regression
B) Attrition
C) Maturation
D) Observer bias
E) Placebo effect

Question 11

Dr.Whetstone is curious about how self-esteem changes as a result of a new counseling program.She is concerned about testing threats in her study.Which of the following would you NOT recommend to her as a way to address this type of threat?

A) Collecting pretest data twice
B) Conducting a posttest-only study
C) Using a different measure of self-esteem at pretest than at posttest
D) Using a comparison group
E) All of the above can be used to address testing threats

Question 12

Which of the following cannot be found in a one-group,pretest/posttest design?

A) A random sample
B) A valid measure
C) A comparison group
D) A manipulation
E) None of the above can be found in this type of design

Question 13

RESEARCH STUDY 10.1
In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam.
Refer to Research Study 10.1 above to answer the following question. Which of the following aspects of Dr.Schulenberg's study allows him to prevent observer bias?

A) Keeping his students unaware of which type of essay they are writing
B) Having his teaching assistant assign students randomly to the two groups
C) Grading the exams himself (a Ph.D.) instead of having his teaching assistant (a college senior) do it
D) Having the person grading the exams unaware of each student's writing group
E) Using the grades from the midterm exam rather than the final exam

Question 14

When interrogating experiments,on which of the big validities should a person focus?

A) Internal validity
B) External validity
C) Construct validity
D) Statistical validity
E) No one validity is more important than another when interrogating experiments

Question 15

RESEARCH STUDY 10.1
In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam.
Refer to Research Study 10.1 above to answer the following question. Dr.Schulenberg likely designed his study so that neither he nor his students knew which group they were in to address which of the following?

A) Placebo effects
B) Attrition
C) Demand characteristics
D) Maturation
E) All of the above

Question 16

Which of the following is true of testing effects?

A) It is an example of an order effect.
B) It can lead to increased/higher scores.
C) It can lead to decreased/lower scores.
D) It can sensitize people to being tested.
E) All of the above are true of testing effects.

Question 17

Which of the following is NOT a method researchers used to identify or correct for attrition?

A) Drop the original/pretest scores of participants who left the study
B) Not allow participants to leave a study once it has started
C) Determine whether those who dropped out of the study had a different pattern of scores than those who stayed in the study
D) Neither a nor b is used
E) Neither a nor c is used

Question 18

Which of the following studies would NOT have a possible threat of observer bias?

A) A study looking at the relationship between the frequency of eating fruits and vegetables and general physical fitness
B) A study looking at the relationship between college GPA and SAT scores
C) A study looking at the number of hours spent listening to music and singing ability
D) A study looking at the rate of text messaging in a day and writing/English composition skill
E) All of the above studies run the risk of observer bias

Question 19

Which of the following threats to internal validity can occur in any study?

A) Observer bias
B) Demand characteristics
C) Placebo effects
D) Both a and b
E) All of the above

Question 20

RESEARCH STUDY 10.1
In previous studies, Dr. Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity). He is curious as to whether this can happen in the college classroom. Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance. In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group). The other half writes a paragraph about what they did to prepare for class (preparation group). He does not know which of his students are writing which paragraph, and the students are not aware they are different writing assignments. To measure academic performance, he gives the students a midterm essay exam and a final exam.
Refer to Research Study 10.1 above to answer the following question. Imagine that in Dr.Schulenberg's study,he notes that all of the students do extremely well on the midterm exam.When he looks at the results of the final exam,he notices that all the students' exam scores went down.Which of the following pattern of results would suggest that there is a threat to internal validity?

A) The final exam scores were lower in the preparation group than the meaning group.
B) The final exam scores were equally low in both groups.
C) The final exam scores were lower than those of students in his fall semester class.
D) The final exam scores were lower than the final exam scores of students of his colleague, Dr. Fao.
E) None of the above would suggest a threat to internal validity.

Question 21

RESEARCH STUDY 10.3
Dr. Paddock is a counseling psychologist who is interested in decreasing adjustment issues in first-year college students. She is curious if having students create collages of their first few weeks of school and then mailing them home will help students feel they have integrated their new life with their old and, as a result, will help them feel less homesick. She samples a group of 100 incoming college freshmen at her university and measures how homesick they are during the first week of school. During Week 4 of school, she has them make the collage and send it home. During Week 7 of school, she measures their homesickness again. She notices a significant reduction in the amount of homesickness from the pretest to the posttest and concludes that her treatment is effective.
Refer to Research Study 10.3 above to answer the following question.
Imagine in Dr.Paddock's study that the pretest scores were incredibly high,indicating a large amount of homesickness in her sample.What kind of threat to internal validity does this pose? How does this affect her conclusion that her treatment for homesickness worked?

Question 22

A confound that keeps a researcher from finding a relationship between two variables is known as a/an:

A) Weak confound
B) Insensitive confound
C) Null confound
D) Reverse confound
E) None of the above

Question 23

RESEARCH STUDY 10.2
Dr. Bloedorn is a health psychologist who researches nutrition. She is curious as to whether a new drink additive will help people consume fewer calories during a meal. The drink additive is a white, odorless, tasteless powder that a person can add to any drink. She collects a random sample of 63 overweight students on campus and measures the calories they eat during lunch, using a bomb calorimeter. She then gives this additive to the same 63 participants to use at dinner and measures how many calories they eat (again, using the bomb calorimeter).
Refer to Research Study 10.2 above to answer the following question. The addition of a group that does not use the drink additive but adds a similar-looking substance that they think is the additive would help Dr.Bloedorn address which of the following threats to internal validity?

A) History
B) Observer bias
C) Instrumentation
D) Placebo effects
E) All of the above

Question 24

In what way does high within-groups variance obscure between-groups variance?

A) It leads to smaller effect sizes.
B) It limits the type of statistical analyses that can be conducted.
C) It causes more overlap between experimental/comparison groups.
D) Both a and c obscure between-group variance.
E) Both b and c obscure between-group variance.

Question 25

RESEARCH STUDY 10.3
Dr. Paddock is a counseling psychologist who is interested in decreasing adjustment issues in first-year college students. She is curious if having students create collages of their first few weeks of school and then mailing them home will help students feel they have integrated their new life with their old and, as a result, will help them feel less homesick. She samples a group of 100 incoming college freshmen at her university and measures how homesick they are during the first week of school. During Week 4 of school, she has them make the collage and send it home. During Week 7 of school, she measures their homesickness again. She notices a significant reduction in the amount of homesickness from the pretest to the posttest and concludes that her treatment is effective.
Refer to Research Study 10.3 above to answer the following question.
Imagine in Dr.Paddock's study that only 90 of the original participants completed the measure of homesickness during Week 7 (10 participants had left the university and were unavailable).Name two things that Dr.Paddock can do to address this possible threat to internal validity and why these should be done.

Question 26

Dr.Deveraux has conducted a study that has resulted in a null effect.Nonetheless,she suspects that there truly is a causal relationship between her independent and dependent variables.Which of the following might be to blame?

A) A weak manipulation
B) An insensitive measure
C) A reverse confound
D) None of the above are reasons
E) All of the above are reasons

Question 27

All of the following are true of ceiling and floor effects EXCEPT:

A) They can be detected by manipulation checks
B) They are only problematic in pretest/posttest designs
C) They can be caused by poorly designed dependent variables
D) They can be caused by poorly designed independent variables
E) All of the above are true

Question 28

Which of the following things CANNOT be done to reduce measurement error?

A) Using more precise measurements
B) Using more reliable measurements
C) Using a pretest/posttest design
D) Collecting measurements from more people
E) All of the above can be done to reduce measurement error

Question 29

Dr.Sanderson is curious as to whether exposing people to violent video games causes them to be more aggressive.She assigns half her participants to play a violent video game for 5 minutes and the other half to play the same game for 25 minutes.Afterward,she has them play a board game and has a well-trained coder determine whether they are very aggressive in their playing style,barely aggressive,or not at all aggressive.She finds that a vast majority of her participants,regardless of group assignment,are rated as very aggressive.This outcome would be known as a/an:

A) Weak manipulation
B) Ceiling effect
C) Floor effect
D) Outlier
E) Large within-group variance

Question 30

RESEARCH STUDY 10.2
Dr. Bloedorn is a health psychologist who researches nutrition. She is curious as to whether a new drink additive will help people consume fewer calories during a meal. The drink additive is a white, odorless, tasteless powder that a person can add to any drink. She collects a random sample of 63 overweight students on campus and measures the calories they eat during lunch, using a bomb calorimeter. She then gives this additive to the same 63 participants to use at dinner and measures how many calories they eat (again, using the bomb calorimeter).
Refer to Research Study 10.2 above to answer the following question. Which of the following threats to internal validity will Dr.Bloedorn NOT be worried about?

A) History
B) Attrition
C) Instrumentation
D) Placebo effects
E) She should be worried about all of the above

Question 31

RESEARCH STUDY 10.3
Dr. Paddock is a counseling psychologist who is interested in decreasing adjustment issues in first-year college students. She is curious if having students create collages of their first few weeks of school and then mailing them home will help students feel they have integrated their new life with their old and, as a result, will help them feel less homesick. She samples a group of 100 incoming college freshmen at her university and measures how homesick they are during the first week of school. During Week 4 of school, she has them make the collage and send it home. During Week 7 of school, she measures their homesickness again. She notices a significant reduction in the amount of homesickness from the pretest to the posttest and concludes that her treatment is effective.
Refer to Research Study 10.3 above to answer the following question.
Imagine in Dr.Paddock's study that only 90 of the original participants completed the measure of homesickness during Week 7 (10 participants had left the university and were unavailable).What kind of threat to internal validity does this pose? How does this affect her conclusion that her treatment for homesickness worked?

Question 32

Dr.Morimoto is curious as to whether exposing people to violent video games causes them to be more aggressive.He assigns half his participants to play a video game for 5 minutes and the other half to play for 7 minutes.He finds that there is no relationship between playing the game longer and being more aggressive.What might be to blame for this null effect?

A) A weak manipulation
B) An insensitive measure
C) A reverse confound
D) Too much within-group variance
E) Ceiling effect

Question 33

Which of the following study types can result in a null effect?

A) Pretest/posttest designs
B) Correlational designs
C) Within-groups designs
D) Posttest-only designs
E) All of the above

Question 34

Which of the following is NOT a reason that a study must yield a null result?

A) A lack of between-group variance
B) Too much within-group variance
C) A "true" null result
D) All of the above are reasons
E) None of the above are reasons

Question 35

RESEARCH STUDY 10.2
Dr. Bloedorn is a health psychologist who researches nutrition. She is curious as to whether a new drink additive will help people consume fewer calories during a meal. The drink additive is a white, odorless, tasteless powder that a person can add to any drink. She collects a random sample of 63 overweight students on campus and measures the calories they eat during lunch, using a bomb calorimeter. She then gives this additive to the same 63 participants to use at dinner and measures how many calories they eat (again, using the bomb calorimeter).
Refer to Research Study 10.2 above to answer the following question. Imagine that Dr.Bloedorn finds no difference between the calories consumed with the drink additive and without.This is known as:

A) Situation noise
B) Within-group variance
C) A null effect
D) Placebo effect
E) None of the above

Question 36

Which of the following things can be done to reduce the effect of individual differences?

A) Using a matched-groups design
B) Using a within-groups design
C) Collecting measurements from more people
D) All of the above can be done to reduce the effect of individual differences
E) Nothing can be done to reduce the effect of individual differences

Question 37

RESEARCH STUDY 10.3
Dr. Paddock is a counseling psychologist who is interested in decreasing adjustment issues in first-year college students. She is curious if having students create collages of their first few weeks of school and then mailing them home will help students feel they have integrated their new life with their old and, as a result, will help them feel less homesick. She samples a group of 100 incoming college freshmen at her university and measures how homesick they are during the first week of school. During Week 4 of school, she has them make the collage and send it home. During Week 7 of school, she measures their homesickness again. She notices a significant reduction in the amount of homesickness from the pretest to the posttest and concludes that her treatment is effective.
Refer to Research Study 10.3 above to answer the following question.
Name two threats to internal validity that are possibly present in Dr.Paddock's study.What other explanation do these threats provide for the results found by Dr.Paddock?

Question 38

RESEARCH STUDY 10.2
Dr. Bloedorn is a health psychologist who researches nutrition. She is curious as to whether a new drink additive will help people consume fewer calories during a meal. The drink additive is a white, odorless, tasteless powder that a person can add to any drink. She collects a random sample of 63 overweight students on campus and measures the calories they eat during lunch, using a bomb calorimeter. She then gives this additive to the same 63 participants to use at dinner and measures how many calories they eat (again, using the bomb calorimeter).
Refer to Research Study 10.2 above to answer the following question. The addition of a control group that does not use the drink additive would help Dr.Bloedorn address which of the following threats to internal validity?

A) History
B) Demand characteristics
C) Instrumentation
D) Placebo effects
E) All of the above

Question 39

RESEARCH STUDY 10.3
Dr. Paddock is a counseling psychologist who is interested in decreasing adjustment issues in first-year college students. She is curious if having students create collages of their first few weeks of school and then mailing them home will help students feel they have integrated their new life with their old and, as a result, will help them feel less homesick. She samples a group of 100 incoming college freshmen at her university and measures how homesick they are during the first week of school. During Week 4 of school, she has them make the collage and send it home. During Week 7 of school, she measures their homesickness again. She notices a significant reduction in the amount of homesickness from the pretest to the posttest and concludes that her treatment is effective.
Refer to Research Study 10.3 above to answer the following question.
What is a comparison group? What kind of comparison group could Dr.Paddock add to her study to address several threats to internal validity? (In other words,what would this comparison group do/not do?)Explain why this addition would help address threats to internal validity.

Question 40

Unsystematic variability in a study is also known as:

A) Error variance
B) Noise
C) Group inconsistency
D) Both a and b
E) All of the above

Question 41

Name the three threats to internal validity that can occur in studies regardless of the use of a comparison group.Why doesn't a comparison group help in these cases?

Question 42

RESEARCH STUDY 10.4
Armand conducts a study for his research method class. He is curious as to whether watching romantic movies makes people more committed to their romantic relationship. He collects a sample of men in dating relationships and divides them into two groups. One group watches a 5-minute clip of a movie in which the main characters are having a romantic first date. The second group watches a 5-minute clip from the same movie in which the main characters break up. After the participants watch the movie clip, they are then asked to write a sentence about their relationship. Armand counts the number of uses of the words we and us as a measure of commitment. After conducting the study, he finds that there is not a statistically significant difference between his two groups.
Refer to Research Study 10.4 above to answer the following question.
Armand's professor suggests that the null effect may be due to a large amount of within-group variance.State three causes of within-group variance in Armand's study.

Question 43

Name two study designs that would address issues of individual differences contributing to within-group variance.If these two designs are not possible,what else could a researcher do?

Question 44

Refer to Research Study 10.4 above to answer the following question.
Provide three reasons why Armand's study may have resulted in null effects.

Question 45

RESEARCH STUDY 10.4
Armand conducts a study for his research method class. He is curious as to whether watching romantic movies makes people more committed to their romantic relationship. He collects a sample of men in dating relationships and divides them into two groups. One group watches a 5-minute clip of a movie in which the main characters are having a romantic first date. The second group watches a 5-minute clip from the same movie in which the main characters break up. After the participants watch the movie clip, they are then asked to write a sentence about their relationship. Armand counts the number of uses of the words we and us as a measure of commitment. After conducting the study, he finds that there is not a statistically significant difference between his two groups.
Refer to Research Study 10.4 above to answer the following question.
Armand's professor suggests that the null effect may be due to insufficient between-group variance.Describe two ways that Armand's study may have had poor between-group variance.

Question 46

Explain why null effects are important in science but are hard to find in the popular press.

Question 47

What is a double-blind study? Explain how this design addresses both the issue of demand characteristics and the issue of observer bias.

Question 48

RESEARCH STUDY 10.4
Armand conducts a study for his research method class. He is curious as to whether watching romantic movies makes people more committed to their romantic relationship. He collects a sample of men in dating relationships and divides them into two groups. One group watches a 5-minute clip of a movie in which the main characters are having a romantic first date. The second group watches a 5-minute clip from the same movie in which the main characters break up. After the participants watch the movie clip, they are then asked to write a sentence about their relationship. Armand counts the number of uses of the words we and us as a measure of commitment. After conducting the study, he finds that there is not a statistically significant difference between his two groups.
Refer to Research Study 10.4 above to answer the following question.
Armand's professor proposes that he replicate the study and double the number of participants he recruits.State which cause(s)of within-group variability will be helped by adding more participants and why this will help.

Question 49

Explain what a manipulation check is and how it can be used to address issues of weak manipulations and insensitive measures.

Question 50

Explain how within-group variance can obscure between group differences.