TEST BANK FOR 7 u 7u
In t e rme dia t e Stat is t ical Inv e s t i g a t ion s 1e Na t h a n Tin t l e, Be t h L. Cha n c e , Ka
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r e n Mc Ga u g hey , So ma Roy , Tod d Swa nson , Jill Va nd e rSto e p
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Ch ap ter 1-6 7 u u
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Ch ap ter 1 7 u
Intermediate Statistical Investigations TestBank 7u 7u 7u 7u
Questiontypes: 7u FIB = Fill in the blank 7u 7u 7u 7u 7u Calc = Calculation 7u 7u
Ma = Matching 7u 7u MS = Multiple select 7u 7u 7u
MC = Multiple choice 7u 7u 7u TF = True-false 7u 7u
CHAPTER1TERMINALLEARNING OUTCOMES 7u 7u 7u 7u
TLO1-1: Apply thesix-step investigative process in the context of a well-designed experiment.
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TLO1-2: Partitioning variation in the response variable into variation explained by the model and unexplained
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variation, and measuring andreporting thepercentage of variation explained
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TLO1-3: Assess the statistical significance of the difference between two groups on a quantitative
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response variable using both simulation and theory-based approaches
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TLO1-4: Compare more than two treatments on a quantitative response using both simulation and
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theory-based approaches
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TLO1-5: Apply Post-hoc analysis after significant F-test (pairwise differences, as well as
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
confidence and prediction intervals for single means)
7u 7u 7u 7u 7u 7u 7u
TLO1-6: Understand statistical power and how it is impacted by sample size, variability within
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groups, number of groups, and significance level
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Section1.1:SourcesofVariationinanExperiment 7u 7u 7u 7u 7u 7u 7u
LO1.1-1:Apply the six-step investigative process.
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LO1.1-2:Distinguish experiments andobservational studies.
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LO1.1-3: Review basic study design principles such as inclusion criteria and random assignment.
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7u LO1.1-4: Define terminology specific to an experimental study (e.g., treatments).
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LO1.1-5: Produce a Sources of Variation diagram for an experiment.
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Questions 1 through 3: A study published in Psychological Science in 2007 examined a possi- ble
7u 7u 7u 7 u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
link between mindset and health. The following is an excerpt from the abstract of the article:
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
―84 female room attendants working in seven different hotels were measured on physiological
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health variables affected by exercise. Those in the informed condition were told that the work
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they do (cleaning hotel rooms) is good exercise and satisfies the Sur- geon General's
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recommendations for an active lifestyle. Examples of how their work was exercise were
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provided. Subjects in the control group were not given this information.‖
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1. Identify the experimental units inthis study. 7u 7u 7u 7u 7u 7u
A. The eighty-four room attendants 7u 7u 7u
FORINSTRUCTOR USE ONLY 7u 7u 7u
,1-2
B. The seven different hotels 7u 7u 7u
C. Thephysiological healthvariables u
7 7u 7u
D. Thetwo groups (informed and control) 7u 7u 7u 7u 7u
7u Ans: A; LO: 1.1-4; Difficulty: Easy; Type: MC
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2. The researchers chose to include room attendants from seven different hotels (as op-
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posed to using stricter inclusion criteria that would limit the study to room attendants at one
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
particular hotel). Describe the consequences of this decision.
7u 7u 7u 7u 7u 7u 7u 7u
Using broader inclusion criteria may
7u (increase/decrease)theamount of variation in 7u 7u 7u 7u 7u 7u 7u 7u 7u
the observed health outcomes. However, this decision also
7u 7u (sup- 7u 7u 7u 7u 7u 7u 7u
ports/limits) generalizability to a larger population of room attendants.
7u 7u 7u 7u 7u 7u 7u 7u 7u
Ans: increase, supports; LO: 1.1-3; Difficulty: Medium; Type: FIB
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3. Room attendants were randomly assigned to either the informed condition or the control
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group. What is the most important reason for the random assignment?
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A. Random assignment ensures that the study is double-blind. 7u 7u 7u 7u 7u 7u 7u
B. Random assignment reduces the impact of outliers. 7u 7u 7u 7u 7u 7u
C. Random assignment creates two groups of room attendants that are as similar as 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
possible, which supports cause-and-effect conclusions.
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D. Random assignment makes it possible to generalize the results to the population. 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
Ans: C; LO: 1.1-3; Difficulty: Medium; Type: MC
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Questions 4 through 6: An online retailer is using an experiment to decide whether to modify their
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website. When visitors type in the web address or click a link to the site, they are randomly re-
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directed to one of two versions of the website: the version that has been in use for the last year
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(version A) or an updated version (version B). The retailer’s goal is to maximize the amount of
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time (in minutes) visitors stay on the site.
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4. Identify the experimental units and variables. Note: One of the answer choices will not be used.
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Experimentalunits: u
7 A. Version of the website (A and B)7u 7u 7u 7u 7u 7u 7u
Explanatoryvariable: u
7 B: Online retailers 7u 7u
Response variable: 7u C: Visitors to the website 7u 7u 7u 7u
D: Time spent on the website (in minutes)
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Ans: Experimental units: C, Explanatory variable: A, Response variable: D; LO: 1.1-4;
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Difficulty: Easy; Type: Ma
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5. Consider two possible models foranalyzing timespent on thisretailer’s website.
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Single-meanmodel: 7u
A. Predictedtimespentonsite=12.33,SEof residuals=4.64 7u 7u 7u 7u 7 u 7u
Separate-meansmodel: 7u
FORINSTRUCTOR USE ONLY 7u 7u 7u
, 1-3
9.9 forVersionA
B. Predictedtimespentonsite= , SEof residuals=3.98
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7u
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14.7 forVersion B 7u 7u
Does the version of the website appear to explain any of the variation in time spent on the site?
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Note: If more thanone of these justifications is appropriate, select multiple answers.
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A. Yes, because the mean time spent on the site is higher for Version B than for
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Version A. 7u 7u
B. Yes, because the SE of the residuals is smaller for the separate-means model
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than for the single-mean model. 7u 7u 7u 7u 7u
C. No, because the mean time spent on the site is not the same for Version A and for
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Version B. 7u 7u
D. No, because the SE of the residuals is smaller for the separate-means model than for
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the single-mean model. 7u 7u 7u
Ans: A, B; LO: 1.1-1; Difficulty: Medium; Type: MS
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6. The researcher decides that the difference between Version A and Version B in this study is
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meaningful. Is it reasonable to generalize these results to all customers of this retailer?
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A. Yes, because visitors to the website were randomly assigned to either Version A or7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
Version B. 7u 7u
B. Yes, because the study’s inclusion criteria would exclude potential subjects who are
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not customers. 7u 7u
C. It depends whether visitors to the website knew about the research question being
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investigated. The study may not be double-blind.
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D. It depends who visited the website during the study period. The sample may not be
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representative. 7u
Ans: D; LO: 1.1-1; Difficulty: Medium; Type: MC
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Questions 7 through 8: Researchers at a university were interested in the effectiveness of a calculus
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workshop program for students who fail Calculus I and need to retake the course. As part of the
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study, students who were retaking Calculus I were allowed to enroll in a cal- culus workshop at
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their own discretion. At the end of the grading term, all students (even those with different
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instructors) took the same final exam. The researchers then compared the scores for those
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who enrolled in the workshop while re-taking calculus to those who
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re-took calculus withoutenrolling in theworkshop.
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7. Is this an experiment? Justify your answer.
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A. Yes, this is an experiment, because there was a treatment group who enrolled in the
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calculus workshop and a control group that did not.
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B. Yes, this is an experiment, because the study was double-blind (as long as the 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
calculus teachers did not know which students enrolled in the workshop).
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C. No, this is an observational study, because it does not take place in a laboratory or other
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tightly controlled research environment. 7u 7u 7u 7u
D. No, this is an observational study, because the choice of whether to participate in the
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workshop was made by the students not the researchers.
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Ans: D; LO: 1.1-2; Difficulty: Easy; Type: MC
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FORINSTRUCTOR USE ONLY 7u 7u 7u
, 1-4
8. Which of thefollowing are sources of unexplained variation in this study? Select all that
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apply.
7u
A. Whether or not students enrolled in the workshop 7u 7u 7u 7u 7u 7u 7u
B. Whether or not students had failed a calculus class in the past 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
C. Student attendance in class (number of absences) 7u 7u 7u 7u 7u 7u
D. Student motivation to study calculus 7u 7u 7u 7u
E. Calculusinstructor u
7
F. Difficulty of thefinal exam 7u 7u 7u 7u
Ans: C, D, E; LO: 1.1-5; Difficulty: Easy; Type: MS
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9. A study published in Athletic Training examined the effects of three different types of knee
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stabilizing braces on agility test speed. College football players from all different positions
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(running back, wide receiver, linebacker, lineman, etc.) were recruited to participate in the
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study. All players in the study had torn their ACL (anterior cruciate ligament) in the past, and
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needed to wear a knee brace to play football. Agility tests were administered in an outdoor
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football stadium, and the time to complete the test was recorded by a Lafayette photoelectric
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Cell and Light Time Unit (in seconds).
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Put the components of the study into the correct boxes in the Sources of Variation Dia-
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gram. Note: Some boxes will include more than one answer.
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Observed variation in: 7u 7u Sources of 7u Sources of 7u
7u explainedvariation u
7 7u unexplainedvariation u
7
Inclusioncriteria: u
7
Design:
A. College football players fromall different positions 7u 7u 7u 7u 7u 7u
B. Type of knee brace 7u 7u 7u
C. Players’currentcondition (health,mood, motivation, etc.) 7u 7u 7u 7u 7u 7u
D. Timeto complete agility test (in seconds) 7u 7u 7u 7u 7u 7u
E. Measurementerror 7u
F. History of torn ACL and need for a knee brace 7u 7u 7u 7u 7u 7u 7u 7u 7u
G. Details of the agility test 7u 7u 7u 7u
H. Players’ natural speed and agility 7u 7u 7u 7u
I. Environmental factors(weather, wind, etc.) 7u 7u 7u 7u
Ans: Observed variation in: D; Inclusion criteria: A, F; Design: G; Sources of explained
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variation: B; Sources of unexplained variation: C, E, H, I; LO: 1.1-5; Difficulty: Medium;
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Type: Ma
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10. In a separate-means model, the standard error of the residuals can be thought of as the
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typical deviation of an observed response from:
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A. Theresiduals (prediction errors) 7u 7u 7u
B. The response predicted by the model (group mean) 7u 7u 7u 7u 7u 7u 7u
C. The overall mean of the response variable 7u 7u 7u 7u 7u 7u
D. The overall mean of the explanatory variable 7u 7u 7u 7u 7u 7u
FORINSTRUCTOR USE ONLY 7u 7u 7u
In t e rme dia t e Stat is t ical Inv e s t i g a t ion s 1e Na t h a n Tin t l e, Be t h L. Cha n c e , Ka
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7 u
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7 7u u
7
r e n Mc Ga u g hey , So ma Roy , Tod d Swa nson , Jill Va nd e rSto e p
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Ch ap ter 1-6 7 u u
7 u
7
Ch ap ter 1 7 u
Intermediate Statistical Investigations TestBank 7u 7u 7u 7u
Questiontypes: 7u FIB = Fill in the blank 7u 7u 7u 7u 7u Calc = Calculation 7u 7u
Ma = Matching 7u 7u MS = Multiple select 7u 7u 7u
MC = Multiple choice 7u 7u 7u TF = True-false 7u 7u
CHAPTER1TERMINALLEARNING OUTCOMES 7u 7u 7u 7u
TLO1-1: Apply thesix-step investigative process in the context of a well-designed experiment.
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
TLO1-2: Partitioning variation in the response variable into variation explained by the model and unexplained
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
variation, and measuring andreporting thepercentage of variation explained
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
TLO1-3: Assess the statistical significance of the difference between two groups on a quantitative
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
response variable using both simulation and theory-based approaches
7u 7u 7u 7u 7u 7u 7u 7u
TLO1-4: Compare more than two treatments on a quantitative response using both simulation and
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
theory-based approaches
7u 7u
TLO1-5: Apply Post-hoc analysis after significant F-test (pairwise differences, as well as
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
confidence and prediction intervals for single means)
7u 7u 7u 7u 7u 7u 7u
TLO1-6: Understand statistical power and how it is impacted by sample size, variability within
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
groups, number of groups, and significance level
7u 7u 7u 7u 7u 7u 7u
Section1.1:SourcesofVariationinanExperiment 7u 7u 7u 7u 7u 7u 7u
LO1.1-1:Apply the six-step investigative process.
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LO1.1-2:Distinguish experiments andobservational studies.
7u 7u 7u 7u 7u
LO1.1-3: Review basic study design principles such as inclusion criteria and random assignment.
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
7u LO1.1-4: Define terminology specific to an experimental study (e.g., treatments).
7u 7u 7u 7u 7u 7u 7u 7u 7u
LO1.1-5: Produce a Sources of Variation diagram for an experiment.
7u 7u 7u 7u 7u 7u 7u 7u 7u
Questions 1 through 3: A study published in Psychological Science in 2007 examined a possi- ble
7u 7u 7u 7 u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
link between mindset and health. The following is an excerpt from the abstract of the article:
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
―84 female room attendants working in seven different hotels were measured on physiological
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
health variables affected by exercise. Those in the informed condition were told that the work
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
they do (cleaning hotel rooms) is good exercise and satisfies the Sur- geon General's
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
recommendations for an active lifestyle. Examples of how their work was exercise were
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
provided. Subjects in the control group were not given this information.‖
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
1. Identify the experimental units inthis study. 7u 7u 7u 7u 7u 7u
A. The eighty-four room attendants 7u 7u 7u
FORINSTRUCTOR USE ONLY 7u 7u 7u
,1-2
B. The seven different hotels 7u 7u 7u
C. Thephysiological healthvariables u
7 7u 7u
D. Thetwo groups (informed and control) 7u 7u 7u 7u 7u
7u Ans: A; LO: 1.1-4; Difficulty: Easy; Type: MC
7u 7u 7u 7u 7u 7u 7u
2. The researchers chose to include room attendants from seven different hotels (as op-
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
posed to using stricter inclusion criteria that would limit the study to room attendants at one
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
particular hotel). Describe the consequences of this decision.
7u 7u 7u 7u 7u 7u 7u 7u
Using broader inclusion criteria may
7u (increase/decrease)theamount of variation in 7u 7u 7u 7u 7u 7u 7u 7u 7u
the observed health outcomes. However, this decision also
7u 7u (sup- 7u 7u 7u 7u 7u 7u 7u
ports/limits) generalizability to a larger population of room attendants.
7u 7u 7u 7u 7u 7u 7u 7u 7u
Ans: increase, supports; LO: 1.1-3; Difficulty: Medium; Type: FIB
7u 7u 7u 7u 7u 7u 7u 7u
3. Room attendants were randomly assigned to either the informed condition or the control
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
group. What is the most important reason for the random assignment?
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
A. Random assignment ensures that the study is double-blind. 7u 7u 7u 7u 7u 7u 7u
B. Random assignment reduces the impact of outliers. 7u 7u 7u 7u 7u 7u
C. Random assignment creates two groups of room attendants that are as similar as 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
possible, which supports cause-and-effect conclusions.
7u 7u 7u 7u 7u
D. Random assignment makes it possible to generalize the results to the population. 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
Ans: C; LO: 1.1-3; Difficulty: Medium; Type: MC
7u 7u 7u 7u 7u 7u 7u
Questions 4 through 6: An online retailer is using an experiment to decide whether to modify their
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website. When visitors type in the web address or click a link to the site, they are randomly re-
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
directed to one of two versions of the website: the version that has been in use for the last year
7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
(version A) or an updated version (version B). The retailer’s goal is to maximize the amount of
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time (in minutes) visitors stay on the site.
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4. Identify the experimental units and variables. Note: One of the answer choices will not be used.
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Experimentalunits: u
7 A. Version of the website (A and B)7u 7u 7u 7u 7u 7u 7u
Explanatoryvariable: u
7 B: Online retailers 7u 7u
Response variable: 7u C: Visitors to the website 7u 7u 7u 7u
D: Time spent on the website (in minutes)
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Ans: Experimental units: C, Explanatory variable: A, Response variable: D; LO: 1.1-4;
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Difficulty: Easy; Type: Ma
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5. Consider two possible models foranalyzing timespent on thisretailer’s website.
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Single-meanmodel: 7u
A. Predictedtimespentonsite=12.33,SEof residuals=4.64 7u 7u 7u 7u 7 u 7u
Separate-meansmodel: 7u
FORINSTRUCTOR USE ONLY 7u 7u 7u
, 1-3
9.9 forVersionA
B. Predictedtimespentonsite= , SEof residuals=3.98
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7u
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14.7 forVersion B 7u 7u
Does the version of the website appear to explain any of the variation in time spent on the site?
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Note: If more thanone of these justifications is appropriate, select multiple answers.
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A. Yes, because the mean time spent on the site is higher for Version B than for
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Version A. 7u 7u
B. Yes, because the SE of the residuals is smaller for the separate-means model
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than for the single-mean model. 7u 7u 7u 7u 7u
C. No, because the mean time spent on the site is not the same for Version A and for
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Version B. 7u 7u
D. No, because the SE of the residuals is smaller for the separate-means model than for
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the single-mean model. 7u 7u 7u
Ans: A, B; LO: 1.1-1; Difficulty: Medium; Type: MS
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6. The researcher decides that the difference between Version A and Version B in this study is
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meaningful. Is it reasonable to generalize these results to all customers of this retailer?
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A. Yes, because visitors to the website were randomly assigned to either Version A or7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
Version B. 7u 7u
B. Yes, because the study’s inclusion criteria would exclude potential subjects who are
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not customers. 7u 7u
C. It depends whether visitors to the website knew about the research question being
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investigated. The study may not be double-blind.
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D. It depends who visited the website during the study period. The sample may not be
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representative. 7u
Ans: D; LO: 1.1-1; Difficulty: Medium; Type: MC
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Questions 7 through 8: Researchers at a university were interested in the effectiveness of a calculus
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workshop program for students who fail Calculus I and need to retake the course. As part of the
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study, students who were retaking Calculus I were allowed to enroll in a cal- culus workshop at
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their own discretion. At the end of the grading term, all students (even those with different
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instructors) took the same final exam. The researchers then compared the scores for those
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who enrolled in the workshop while re-taking calculus to those who
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re-took calculus withoutenrolling in theworkshop.
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7. Is this an experiment? Justify your answer.
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A. Yes, this is an experiment, because there was a treatment group who enrolled in the
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calculus workshop and a control group that did not.
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B. Yes, this is an experiment, because the study was double-blind (as long as the 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
calculus teachers did not know which students enrolled in the workshop).
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C. No, this is an observational study, because it does not take place in a laboratory or other
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tightly controlled research environment. 7u 7u 7u 7u
D. No, this is an observational study, because the choice of whether to participate in the
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workshop was made by the students not the researchers.
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Ans: D; LO: 1.1-2; Difficulty: Easy; Type: MC
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FORINSTRUCTOR USE ONLY 7u 7u 7u
, 1-4
8. Which of thefollowing are sources of unexplained variation in this study? Select all that
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apply.
7u
A. Whether or not students enrolled in the workshop 7u 7u 7u 7u 7u 7u 7u
B. Whether or not students had failed a calculus class in the past 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u 7u
C. Student attendance in class (number of absences) 7u 7u 7u 7u 7u 7u
D. Student motivation to study calculus 7u 7u 7u 7u
E. Calculusinstructor u
7
F. Difficulty of thefinal exam 7u 7u 7u 7u
Ans: C, D, E; LO: 1.1-5; Difficulty: Easy; Type: MS
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9. A study published in Athletic Training examined the effects of three different types of knee
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stabilizing braces on agility test speed. College football players from all different positions
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(running back, wide receiver, linebacker, lineman, etc.) were recruited to participate in the
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study. All players in the study had torn their ACL (anterior cruciate ligament) in the past, and
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needed to wear a knee brace to play football. Agility tests were administered in an outdoor
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football stadium, and the time to complete the test was recorded by a Lafayette photoelectric
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Cell and Light Time Unit (in seconds).
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Put the components of the study into the correct boxes in the Sources of Variation Dia-
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gram. Note: Some boxes will include more than one answer.
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Observed variation in: 7u 7u Sources of 7u Sources of 7u
7u explainedvariation u
7 7u unexplainedvariation u
7
Inclusioncriteria: u
7
Design:
A. College football players fromall different positions 7u 7u 7u 7u 7u 7u
B. Type of knee brace 7u 7u 7u
C. Players’currentcondition (health,mood, motivation, etc.) 7u 7u 7u 7u 7u 7u
D. Timeto complete agility test (in seconds) 7u 7u 7u 7u 7u 7u
E. Measurementerror 7u
F. History of torn ACL and need for a knee brace 7u 7u 7u 7u 7u 7u 7u 7u 7u
G. Details of the agility test 7u 7u 7u 7u
H. Players’ natural speed and agility 7u 7u 7u 7u
I. Environmental factors(weather, wind, etc.) 7u 7u 7u 7u
Ans: Observed variation in: D; Inclusion criteria: A, F; Design: G; Sources of explained
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variation: B; Sources of unexplained variation: C, E, H, I; LO: 1.1-5; Difficulty: Medium;
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Type: Ma
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10. In a separate-means model, the standard error of the residuals can be thought of as the
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typical deviation of an observed response from:
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A. Theresiduals (prediction errors) 7u 7u 7u
B. The response predicted by the model (group mean) 7u 7u 7u 7u 7u 7u 7u
C. The overall mean of the response variable 7u 7u 7u 7u 7u 7u
D. The overall mean of the explanatory variable 7u 7u 7u 7u 7u 7u
FORINSTRUCTOR USE ONLY 7u 7u 7u
