Deck 6: Getting the Big Picture

Question 1

Case study 6.4
Smoking during pregnancy and child's iq
For Questions use the following narrative
Narrative: Case study 6.4 summary
Four hundred women participated in this study.Researchers found that children ages 3 and 4 whose mothers smoked 10 or more cigarettes a day during pregnancy scored about 9 points lower on intelligence tests than the children of nonsmokers.The gap narrowed to 4 points against children of nonsmokers when a wide range of interrelated factors were controlled for.The lead researcher was quoted as saying "It is comparable to the effects that moderate levels of lead exposure have on children's IQ scores."

{Case study 6.4 narrative} What is one possible confounding variable that may or may not have been controlled for in this study?

Answer 1

Any reasonable answer ok.examples: socio-economic status; exposure to secondhand smoke; mothers' diet, education, age, drug use; parents' iq; prenatal care; duration of breastfeeding, etc.

Question 2

What is the final question you should ask when you read the results of research involving statistical studies?

A)Was the research based on an observational study or an experiment?
B)What were the statistical results of the study?
C)What were the conclusions of the study and to whom do they apply?
D)Will you make any changes in your lifestyle, attitudes, or beliefs as a result of this study?

Answer 2

Will you make any changes in your lifestyle, attitudes, or beliefs as a result of this study?

Question 3

Case study 6.1
CAN MEDITATION IMPROVE TEST SCORES?
For Questions use the following narrative
Narrative: Case study 6.1 summary
The case study investigates whether mindfulness mediation can help college students perform better on exams.Forty-eight undergraduates were recruited and randomly assigned to either a meditation class or a nutrition class.For the two treatments, scores were measured on a verbal reasoning test both before the treatments and after the treatments.The test scores for the nutrition group showed no change, whereas the test scores for the meditation group improved from 460 before the treatment to 520 afterwards.This was a 16-percentile increase.

{Case study 6.1 narrative} One of your classmates argues that test scores are expected to improve in sequential testing scenarios.The argument asserts that the first test serves somewhat as a "test preparation course" for the second test.If this is true, the study may say more about the negative effect of the nutrition class than it does about the positive effect of the meditation class.How can the experiment be redesigned to control for this lurking factor?

Answer 3

Any reasonable answer ok.example: create a third randomly-selected group that receives neither the meditation training nor the nutrition class.

Question 4

Case study 6.2
can eating cereal reduce obesity?
For Questions use the following narrative
Narrative: Case study 6.2 summary
This case study examines the relationship between breakfast eating habits and obesity in school kids from low-income families.Researchers compared body mass indices (BMIs) of 625 children to the number of times - out of 9 days - the children reported eating cereal for breakfast.Kids who reported eating breakfast 4 out of 9 days tended to be in the 95th percentile for BMIs, indicating obesity.Kids who reported eating cereal 9 out of 9 days tended to be in the 65th percentile, indicating healthy weights.The study was funded in part by a regional dairy council.

{Case study 6.2 narrative} This was what type of study?

A)Case-control design
B)Matched-pairs experiment
C)Observational study
D)None of the above

Question 5

Case study 6.1
CAN MEDITATION IMPROVE TEST SCORES?
For Questions use the following narrative
Narrative: Case study 6.1 summary
The case study investigates whether mindfulness mediation can help college students perform better on exams.Forty-eight undergraduates were recruited and randomly assigned to either a meditation class or a nutrition class.For the two treatments, scores were measured on a verbal reasoning test both before the treatments and after the treatments.The test scores for the nutrition group showed no change, whereas the test scores for the meditation group improved from 460 before the treatment to 520 afterwards.This was a 16-percentile increase.

{Case study 6.1 narrative} Is there a possible experimenter effect in this study? Explain.

Question 6

Case study 6.1
CAN MEDITATION IMPROVE TEST SCORES?
For Questions use the following narrative
Narrative: Case study 6.1 summary
The case study investigates whether mindfulness mediation can help college students perform better on exams.Forty-eight undergraduates were recruited and randomly assigned to either a meditation class or a nutrition class.For the two treatments, scores were measured on a verbal reasoning test both before the treatments and after the treatments.The test scores for the nutrition group showed no change, whereas the test scores for the meditation group improved from 460 before the treatment to 520 afterwards.This was a 16-percentile increase.

{Case study 6.1 narrative} Is this study ecologically valid? Explain why or why not.

Question 7

What is the final question you should ask when you read the results of research that involves statistical studies?

Question 8

Case study 6.3
drinking, driving, and the supreme court
For Questions use the following narrative
Narrative: Case study 6.3 summary
This case study involves a decision made by the Supreme Court based on statistical evidence.In the early 1970s, a young man between 18 and 20 years old challenged an Oklahoma state law prohibiting the sale of 3.2% beer to males under 21 while allowing its sale to females of the same age group.The Court ruled the law unconstitutional.They considered two sets of data in making their decision.The first data set consisted of the number of arrests for driving under the influence and for drunkenness for most of the state of Oklahoma from September 1 to December 31, 1973, along with population figures.Based on those figures they determined that 2% of all males aged 18-21 were arrested for one of the two offenses mentioned, compared to only 0.18% of the young female population.The second set of data came from a "random roadside survey" of cars on the streets and highways around Oklahoma City during August 1972 and August 1973.11.4% of the males under 21 had a blood alcohol level over .01, compared to 9.4% of the females under 21.

{Case study 6.3 narrative} Evaluate the sample used to obtain the second data set.

Question 9

Case study 6.2
can eating cereal reduce obesity?
For Questions use the following narrative
Narrative: Case study 6.2 summary
This case study examines the relationship between breakfast eating habits and obesity in school kids from low-income families.Researchers compared body mass indices (BMIs) of 625 children to the number of times - out of 9 days - the children reported eating cereal for breakfast.Kids who reported eating breakfast 4 out of 9 days tended to be in the 95th percentile for BMIs, indicating obesity.Kids who reported eating cereal 9 out of 9 days tended to be in the 65th percentile, indicating healthy weights.The study was funded in part by a regional dairy council.

{Case study 6.2 narrative} What is one possible confounding factor in this experiment?

Question 10

Case study 6.3
drinking, driving, and the supreme court
For Questions use the following narrative
Narrative: Case study 6.3 summary
This case study involves a decision made by the Supreme Court based on statistical evidence.In the early 1970s, a young man between 18 and 20 years old challenged an Oklahoma state law prohibiting the sale of 3.2% beer to males under 21 while allowing its sale to females of the same age group.The Court ruled the law unconstitutional.They considered two sets of data in making their decision.The first data set consisted of the number of arrests for driving under the influence and for drunkenness for most of the state of Oklahoma from September 1 to December 31, 1973, along with population figures.Based on those figures they determined that 2% of all males aged 18-21 were arrested for one of the two offenses mentioned, compared to only 0.18% of the young female population.The second set of data came from a "random roadside survey" of cars on the streets and highways around Oklahoma City during August 1972 and August 1973.11.4% of the males under 21 had a blood alcohol level over .01, compared to 9.4% of the females under 21.

{Case study 6.3 narrative} Assuming the Supreme Court did take these data sets into account to make their decision, why did they determine the law to be unconstitutional when each data set appears to favor those defending the law? Discuss each data set separately.

Question 11

Case study 6.4
Smoking during pregnancy and child's iq
For Questions use the following narrative
Narrative: Case study 6.4 summary
Four hundred women participated in this study.Researchers found that children ages 3 and 4 whose mothers smoked 10 or more cigarettes a day during pregnancy scored about 9 points lower on intelligence tests than the children of nonsmokers.The gap narrowed to 4 points against children of nonsmokers when a wide range of interrelated factors were controlled for.The lead researcher was quoted as saying "It is comparable to the effects that moderate levels of lead exposure have on children's IQ scores."

{Case study 6.4 narrative} Based on this study, can a cause and effect relationship between smoking during pregnancy and child's IQ be established?

Question 12

Name two (of the seven) steps involved in evaluating a study.

Question 13

Suppose you are reading a newspaper article discussing the results of the latest medical study but the information is incomplete (as in many cases with the media).What should you do?

A)Disregard the results because they can't be checked out fully.
B)Be suspicious of the results; if some information is missing, perhaps there is a reason they don't want you to know.
C)See if you can find the original source of the report or contact the authors for the missing information.
D)Assume that the results are valid because they appeared in a newspaper.

Question 14

Case study 6.1
CAN MEDITATION IMPROVE TEST SCORES?
For Questions use the following narrative
Narrative: Case study 6.1 summary
The case study investigates whether mindfulness mediation can help college students perform better on exams.Forty-eight undergraduates were recruited and randomly assigned to either a meditation class or a nutrition class.For the two treatments, scores were measured on a verbal reasoning test both before the treatments and after the treatments.The test scores for the nutrition group showed no change, whereas the test scores for the meditation group improved from 460 before the treatment to 520 afterwards.This was a 16-percentile increase.

{Case study 6.1 narrative} Which of the following describes a possible difficulty with this study?

A)Confounding variables
B)Interacting variables
C)Ecological validity
D)All of the above

Question 15

Case study 6.1
CAN MEDITATION IMPROVE TEST SCORES?
For Questions use the following narrative
Narrative: Case study 6.1 summary
The case study investigates whether mindfulness mediation can help college students perform better on exams.Forty-eight undergraduates were recruited and randomly assigned to either a meditation class or a nutrition class.For the two treatments, scores were measured on a verbal reasoning test both before the treatments and after the treatments.The test scores for the nutrition group showed no change, whereas the test scores for the meditation group improved from 460 before the treatment to 520 afterwards.This was a 16-percentile increase.

{Case study 6.1 narrative} This experiment involved what type of design?

A)Case-control design
B)Repeated measures design
C)Matched-pairs design
D)None of the above

Question 16

Case study 6.3
drinking, driving, and the supreme court
For Questions use the following narrative
Narrative: Case study 6.3 summary
This case study involves a decision made by the Supreme Court based on statistical evidence.In the early 1970s, a young man between 18 and 20 years old challenged an Oklahoma state law prohibiting the sale of 3.2% beer to males under 21 while allowing its sale to females of the same age group.The Court ruled the law unconstitutional.They considered two sets of data in making their decision.The first data set consisted of the number of arrests for driving under the influence and for drunkenness for most of the state of Oklahoma from September 1 to December 31, 1973, along with population figures.Based on those figures they determined that 2% of all males aged 18-21 were arrested for one of the two offenses mentioned, compared to only 0.18% of the young female population.The second set of data came from a "random roadside survey" of cars on the streets and highways around Oklahoma City during August 1972 and August 1973.11.4% of the males under 21 had a blood alcohol level over .01, compared to 9.4% of the females under 21.

{Case study 6.3 narrative} What is one possible confounding factor in the study represented by the first data set?

Question 17

Case study 6.2
can eating cereal reduce obesity?
For Questions use the following narrative
Narrative: Case study 6.2 summary
This case study examines the relationship between breakfast eating habits and obesity in school kids from low-income families.Researchers compared body mass indices (BMIs) of 625 children to the number of times - out of 9 days - the children reported eating cereal for breakfast.Kids who reported eating breakfast 4 out of 9 days tended to be in the 95th percentile for BMIs, indicating obesity.Kids who reported eating cereal 9 out of 9 days tended to be in the 65th percentile, indicating healthy weights.The study was funded in part by a regional dairy council.

{Case study 6.2 narrative} Which of the following describes a possible difficulty with this study?

A)Hawthorne effect
B)Confounding variables
C)Ecological validity
D)All of the above

Question 18

Case study 6.3
drinking, driving, and the supreme court
For Questions use the following narrative
Narrative: Case study 6.3 summary
This case study involves a decision made by the Supreme Court based on statistical evidence.In the early 1970s, a young man between 18 and 20 years old challenged an Oklahoma state law prohibiting the sale of 3.2% beer to males under 21 while allowing its sale to females of the same age group.The Court ruled the law unconstitutional.They considered two sets of data in making their decision.The first data set consisted of the number of arrests for driving under the influence and for drunkenness for most of the state of Oklahoma from September 1 to December 31, 1973, along with population figures.Based on those figures they determined that 2% of all males aged 18-21 were arrested for one of the two offenses mentioned, compared to only 0.18% of the young female population.The second set of data came from a "random roadside survey" of cars on the streets and highways around Oklahoma City during August 1972 and August 1973.11.4% of the males under 21 had a blood alcohol level over .01, compared to 9.4% of the females under 21.

{Case study 6.3 narrative} Which of the following describes difficulties with one or both of the studies in this case?

A)Generalizability
B)Confounding variables
C)Sampling problems
D)All of the above

Question 19

Case study 6.2
can eating cereal reduce obesity?
For Questions use the following narrative
Narrative: Case study 6.2 summary
This case study examines the relationship between breakfast eating habits and obesity in school kids from low-income families.Researchers compared body mass indices (BMIs) of 625 children to the number of times - out of 9 days - the children reported eating cereal for breakfast.Kids who reported eating breakfast 4 out of 9 days tended to be in the 95th percentile for BMIs, indicating obesity.Kids who reported eating cereal 9 out of 9 days tended to be in the 65th percentile, indicating healthy weights.The study was funded in part by a regional dairy council.

{Case study 6.2 narrative} Based on this study, can a cause and effect relationship between cereal consumption and obesity be made?

Question 20

Case study 6.3
drinking, driving, and the supreme court
For Questions use the following narrative
Narrative: Case study 6.3 summary
This case study involves a decision made by the Supreme Court based on statistical evidence.In the early 1970s, a young man between 18 and 20 years old challenged an Oklahoma state law prohibiting the sale of 3.2% beer to males under 21 while allowing its sale to females of the same age group.The Court ruled the law unconstitutional.They considered two sets of data in making their decision.The first data set consisted of the number of arrests for driving under the influence and for drunkenness for most of the state of Oklahoma from September 1 to December 31, 1973, along with population figures.Based on those figures they determined that 2% of all males aged 18-21 were arrested for one of the two offenses mentioned, compared to only 0.18% of the young female population.The second set of data came from a "random roadside survey" of cars on the streets and highways around Oklahoma City during August 1972 and August 1973.11.4% of the males under 21 had a blood alcohol level over .01, compared to 9.4% of the females under 21.

{Case study 6.3 narrative} What type of study produced the first data set?

A)Case-control design
B)Repeated measures design
C)Matched-pairs design
D)None of the above

Question 21

Case study 6.4
Smoking during pregnancy and child's iq
For Questions use the following narrative
Narrative: Case study 6.4 summary
Four hundred women participated in this study.Researchers found that children ages 3 and 4 whose mothers smoked 10 or more cigarettes a day during pregnancy scored about 9 points lower on intelligence tests than the children of nonsmokers.The gap narrowed to 4 points against children of nonsmokers when a wide range of interrelated factors were controlled for.The lead researcher was quoted as saying "It is comparable to the effects that moderate levels of lead exposure have on children's IQ scores."

{Case study 6.4 narrative} This was what type of study?

A)Case-control design
B)Observational study
C)Matched-pairs experiment
D)None of the above

Question 22

Case study 6.4
Smoking during pregnancy and child's iq
For Questions use the following narrative
Narrative: Case study 6.4 summary
Four hundred women participated in this study.Researchers found that children ages 3 and 4 whose mothers smoked 10 or more cigarettes a day during pregnancy scored about 9 points lower on intelligence tests than the children of nonsmokers.The gap narrowed to 4 points against children of nonsmokers when a wide range of interrelated factors were controlled for.The lead researcher was quoted as saying "It is comparable to the effects that moderate levels of lead exposure have on children's IQ scores."

{Case study 6.4 narrative} Which of the following describes difficulties with this study?

A)Generalizability
B)Confounding variables
C)Possible experimenter effect
D)All of the above