Language of evaluation
1-3)
(3 pts each) We wish to test the model that the incidence of
gonorrhea declines after beer taxes are raised. For the following possible data, which consequences (A, B,
C) apply? Note that this question is not about causation versus correlation, only about data and a model that
happens to describe a correlation.
(MTF)
A) The data are
inconsistent with the model |
B) The data are irrelevant
to the model |
C) The data support the
model |
1) Data: 20 spins
on a roulette wheel, 15 are Red
A B C
2) Data: In
two separate instances, the incidence of hepatitis B infections was unchanged
after beer taxes were raised. (Hepatitis B is not gonorrhea.) A B C
3) Data: In two separate instances, the
incidence of gonorrhea was unchanged after beer taxes were raised. A B C
4) (12 pts)
The following points pertain to the book and lecture on evaluation. Which
statements are true? (MTF).
(A) Data are considered inconsistent with models because all models are false.
(B) Classifying data as irrelevant to a model means that the data could not possibly
refute it no matter how they turned out.
(C) Classifying data as irrelevant to a model means that the data were not gathered
according to the Ideal Data template.
(D) In considering guilt versus innocence of a suspect in
a crime, the law specifies that we adopt the view that the suspect is
considered innocent until proven guilty (consider this statement true). The
model of innocence is an example of a null model because it is the model we accept until evidence forces us to
reject it.
(E) In science and in many aspects of society, our
willingness to reject a null model increases as evidence accumulates against
that model. For example, in class, our acceptance of the safety of a vaccine
(against the null model that the vaccine was not safe) increased as the sample
of successful trials increased.
(F) In a Pepsi
versus Coca-Cola taste test, one
would use either null model that Pepsi tastes best or that Coca-Cola tastes best.
(G) By definition, once a model has been accepted, that
model cannot be refuted in further tests.
(H) The criteria for acceptance of a model are rigid in
science and society, and there is little legitimate room for disagreement as to
whether a model should be accepted or not.
(I) A null model is part of every properly designed
study. If the study does not have
a null model, then it is not properly designed.
Correlations
5) (6 pts) We considered the correlation that people living in cities/towns with high fluoride in the water supply have low tooth decay rates compared to people living in towns with low fluoride (fluoride level is variable X, tooth decay rate is variable Y). Which of the following causal models of this correlation use a Òthird variableÓ to explain the correlation (meaning that X and Y are not causally related)? MTF
Causal model
|
Cause invoke a third variable?
|
high fluoride makes teeth
tougher against the agents causing tooth decay |
Fill in 5 (A) if a 3rd variable is invoked |
water supplies with high
fluoride also have high magnesium, and it is the magnesium responsible for
low tooth decay |
Fill in 5 (B) if a 3rd variable is
invoked |
people living in areas of
high fluoride have higher incomes and can afford better dental hygiene;
better dental hygiene is what lowers tooth decay. |
Fill in 5 (C) if a 3rd variable is
invoked |
high fluoride kills the
bacteria in the mouth that cause tooth decay |
Fill in 5 (D) if a 3rd variable is
invoked |
6-8. (3 points each) Researchers have discovered that HIV (the AIDS virus)
is more frequently transmitted heterosexually (vaginal intercourse) in Africa
than in North America, where it is chiefly transmitted homosexually. They have
also discovered that circumcision is at a much lower incidence in Africa than
in North America. They have thus proposed that circumcision is a way of
reducing the spread of HIV.
Use the following variables:
Variable 1:
continent
Variable 2:
incidence of heterosexual HIV transmission
Variable 3:
incidence of circumcision
For each of the following questions, you are
given a pair of these variables.
You are asked to choose among the following 3 options that best
characterizes their relationship in the problem description above.
(A) no correlation or causation is
indicated. |
(B) a correlation is indicated, but no
causation between the variables is suggested |
(C) a correlation is indicated and a causal
relation between the variables is suggested. |
For each pair of variables given below, which
option applies (one answer each)?
6. Variables
1 & 2: (A)
(B) (C)
7. Variables
1 & 3: (A)
(B) (C)
8.Variables
2 & 3: (A)
(B) (C)
9) (5pts)
Again consider a correlation between fluoride and low tooth decay rates. If magnesium (not fluoride) in drinking
water is the true cause of low tooth decay rates, which tooth decay rates are
expected in cells 1 & 2 of the following table? Assume that no other
variables besides fluoride and magnesium are important. (one answer only)
|
|
Magnesium: |
|
|
|
present |
absent |
fluoride: |
present |
low decay |
(1) |
absent |
(2) |
high decay |
A) 1 is high, 2 is high |
C) 1 is low, 2 is high |
B) 1 is high, 2 is low |
D) 1 is low, 2 is low |
10.
(5 pts; hard; options have changed)
New diagnostic methods have allowed us to detect cancers at earlier ages than
in the past, and the average age of a person first diagnosed with cancer has
decreased. In addition, people
have been living longer from the times of their diagnosis. That is, if A is the
average age of a person when cancer is diagnosed and Y is the number of years a
person lives beyond diagnosis, there is a (negative) correlation between A and
Y (Y increases as A decreases). Note that the average age of death of a
diagnosed person is A+Y. Which of
the following models are consistent
with this correlation? That is,
which models are not rejected by
this correlation? MTF
(A)
There has been no
change in the age at which people
diagnosed with cancer die.
(B)
There has been no
change in the number of years a
person lives beyond their diagnosis of cancer.
(C)
Late diagnosis causes a person to live to a later age than does early
diagnosis.
(D)
Early diagnosis causes a person to live to a later age than does late
diagnosis.
Electromagnetic
Fields
11. (5 pts) Scientists currently accept which of the following
models about EMFs? (It is of course possible that a model which is supported
now may be rejected in the future.)
MTF
(A) Most of the
available data concerning EMFs and cancer are correlational
(B) If residential
EMFs from power lines and transformers do cause leukemia, they increase risk by
less than a factor of 2.
(C) Alternating
current generates EMFs
(D) Gamma rays are
a major source of the low-frequency EMFs that US citizens receive.
(E) The intensity
(strength or "brightness) of an EMF falls off quickly as one moves away
from the source of the field
Controls
12. (6 pts) Each of rows (A)-(G) describe different treatments
that could be applied to humans in generating data on heart disease. The treatments differ in which factors
are present (indicated by Ò+Ó) or absent (-). Factor 1 is the use of a
cholesterol-lowering drug (statins); factor 2 is a diet low in saturated fat;
factor 3 is moderate exercise; factor 4 is a diet with daily fish oil; factor 5
is one ounce per day of alcohol.
Which two treatments would you want to
compare to determine if factor 1 is correlated with differences in heart
disease when all other factors are controlled? In evaluating possible answers, pick any comparison that controls for
all unwanted factors, and assume
that these treatments differ only in the ways stated. Mark exactly two options,
or none if none apply. Each
row (each option) describes a different set of conditions, so to know which
factors would be applied in a treatment, you look across the row. If multiple combinations satisfy the
problem, any correct combination will be accepted. (Two answers or None; options have changed).
|
factor |
|||||
Option |
|
1 |
2 |
3 |
4 |
5 |
(A) |
- |
+ |
+ |
+ |
+ |
|
(B) |
- |
+ |
- |
+ |
- |
|
(C) |
+ |
+ |
+ |
- |
+ |
|
(D) |
- |
- |
+ |
+ |
- |
|
(E) |
+ |
- |
- |
- |
- |
|
(F) |
+ |
- |
+ |
- |
+ |
|
(G) |
+ |
+ |
- |
+ |
- |
13. (6 pts) Mark all of the following statements about controls that
are correct. MTF
(A) Controls are present in any (defined) correlation,
whether the correlation is zero, negative, or positive.
(B)
A control establishes a
baseline.
(C)
In the video comparing
human and penguin intelligence, the last stage of the IQ test controlled for
environmental and language differences.
(D)
In the video comparing human and penguin
intelligence, brain size was not considered a good model of intelligence
because there was no way to control for differences in body size between
penguins and humans.
(E)
The choice of subjects
both blindly and randomly guarantees that a control is present.
(F)
One of our themes is
that experiments make the best controls.
What this theme means, in part, is that a test cannot be considered an
experiment unless it has a control group.
(G)
To control for factor X,
X must be absent in all study groups
14. (6 pts) An epidemiologist does a survey to evaluate whether a
personÕs tendency to acquire a criminal habit later in life can be predicted
from characteristics of their environment early in life. Only correlational
data are gathered (no experiment).
For such a study, which of the following options are true? MTF
A) Characteristics that are the same for all individuals
in the study (e.g., country of residence, if the study was confined to one
country) would not be controlled
for because they are not variables in the study.
B) Variables that were not recorded about each individual
in the study could not knowingly
be controlled for.
C) Variables that were recorded about each individual in
the study could be analyzed so that they were controlled for.
D) Suppose
the goal was to assess whether the childhood neighborhood was a factor in
development of a criminal habit.
If four different neighborhoods were chosen for the study, then the
random choice of which individuals within each of those neighborhoods to
include in the study would ensure that all variables besides neighborhood would
be controlled (on average).
Experiments
15.
(4pts) The test of FC shown in the
video was an experiment because
(one only)
A) it included controls |
C) it manipulated the
normal FC environment |
E) all of the above (A-D) |
B) it was blind |
D) it included several
levels of replication |
|
16. (6 pts) On-line survey and/or video
of horoscope experiment. Which of the following options apply to the on-line
survey given to the class and/or the horoscope experiment, as shown or
discussed in lecture? MTF
A)
Randomization. In light of the goal, the study would
have been improved if the distribution of who got which survey had been randomized,
both in our class and in the video.
B)
Blind was essential to
the goal of the studies. If
everyone had known the true purpose of the survey (and had known the design),
it is likely that our class and the one shown would not have rated the
personality description so highly.
C)
Replication. Similar outcomes have been obtained in
previous years of Bio301D.
Furthermore, essentially the same outcome of positive responses was
shown in the video.
D)
Controls. It is ambiguous whether controls were
present in the video.
In the following questions, consider italicized phrases and sentences as true.
17. (6 pts) Prisoners of Silence (Facilitated Communication,
or FC). Which of the following options either depict what was shown
in the video, or correctly explains the nature of the study done in the
video? If any part of an option is
incorrect, consider the option incorrect and do not mark it. MTF.
(A) Model tested: the video showed that
allegations of sexual abuse had been typed by autistic children when assisted
by their facilitator. The model tested in the video was that
the autistic child was not being truthful about the sexual abuse.
(B)
The need for an
experiment. In the normal FC environment, the Facilitator knew what answer
was expected. This was the basic
problem that required an experimental test to determine whether the
communications were real.
(C) Evaluation of results:
the video showed several people who interpreted the outcome of the tests as
evidence that FC does not represent communication by the child. A
legitimate criticism of these tests and of that interpretation is that the
child was intimidated by the test environment and, consequently, could not
perform well when being tested.
(D) Blind: Blind was
an essential feature of the design.
That is, the goal of the experiment required at least that the
Facilitator not know what the child was being asked.
18. (5 pts) This question refers to the palm-reading segment
shown in the "Secrets of the Psychics" video. Which statements about models and
design features are true? Ray Hayman was the palm reader.
MTF
A) Ray had been a skeptic of palm reading throughout his
college years, and he designed palm reading experiments to convince others it
was bogus.
B) RayÕs palm reading experiments were done on photographs
of hands, and his readings were transcribed and given to the people for
evaluation.
C) The controls for his experiments were people given the
written description of readings done on pictures of their own hands; the
treatments were people given the written description of readings done on
pictures of hands from other people.
D) There are explicit (written) protocols for palm
reading that Ray had used to teach himself the proper technique.
One more page ...
Standardized Field Sobriety Tests (SFST)
19. (12 pts) Which of the
following options are true about
the SFST lectures? MTF
A) There are specific protocols for conducting the
SFST. These protocols describe how
to give instructions to perform the test as well as how to evaluate the
performance.
B) Class discussed 3 different tests in the SFST: Walk and Turn, Horizontal Gaze
Nystagmus, and One Leg Stand.
C) Baseline data indicate that a sober person fails any
one of the 3 tests only 5% of the time.
The failure rate is slightly higher for people over 50 than for people
under 50.
D) There have been ÒvalidationÓ studies showing that
officers in the field (on duty, encountering drivers as they normally do) can
use the SFST to reliably assess whether a driver exceeds the 0.08% blood
alcohol limit approximately 90% of the time.
E) The validation studies done in the field have been
blind in the sense that the officer performing the SFST did not know the blood
alcohol content of the driver but have been non-blind in the sense that the
officer knew that an observer was recording the officerÕs conduct of the test.
F) A graph showed that the number of highway deaths
per million vehicle miles has declined over the last 40 years. It
was also shown that SFST use and DWI arrests were implemented about halfway
during this 40-year period and that the rate of highway deaths continued to
decline after this implementation. The
cause of this decline in highway death rate is therefore at least in part due
to the implementation of SFST and DWI arrests.
G) The scoring of the SFST is somewhat arbitrary because
some deviations are not always clear-cut.
H) If you score 2 points or more on any of the 3 SFSTs,
the officer is obliged to arrest you.
I) Starting either the WAT and OLS test before instructed
to do so is scored against you.
J) Texas law allows you to be arrested for driving under
the influence only if your blood alcohol content exceeds 0.08% or if
your performance on the SFST indicates your are over this limit.
K) The fact that you blow much less than 0.08% on a
breathalyzer will not necessarily be grounds for releasing you, because it is
commonly assumed that drivers with low blood-alcohol are under the influence of
other drugs. However, direct
evidence of these ÒotherÓ drugs is often not sought by the government.
20. (5pts) Key code, name, and pad number. Fill in (A B) on scantron field 20 to indicate your key for this version of the exam. Be sure your name and pad number are correctly bubbled in on the scantron and that your name is on this exam form. If your name is not on this copy as well as the scantron form, you can be penalized 40 points, if we can even determine that you took the test.