2

1. (5 pts) The following statements pertain to the first-day survey and the discussion of it in the following lectures. Which statements are true? (multiple True/False = MTF) The framework given in lecture to which this question applies is somewhat different in 2007 than in 2006. So some of the options are not worth trying to understand.

(A) Highly varied responses were observed for some statements. The discussion that followed suggested that most of the variation in responses was due to students having different levels of direct knowledge of the relevant evidence. Not a good fit to 2007. Not true, but we didn’t mention “direct knowledge of the relevant evidence” this year.

(B) Comparing classes from different years, responses to the same statement are usually similar. Yes, as can be observed from looking at them and as was covered in class.

(C) It was suggested that emotional factors were important in many of the responses. Not a good fit to 2007. We noted that emotional factors went into a person’s acceptance of a statement, but I don’t know that we made a point of it in the context of specific responses.

(D) More students considered it “definitely” or “probably” true that governments had concealed evidence that aliens have landed on earth than considered it definitely or probably true that aliens have even landed. Yes. We noted this case as an example of the appeal of a conspiracy theory.

(E) The purpose of this survey was to assess your baseline knowledge of basic biological facts. No, the motivation was to think about how and why we differ in our beliefs.

Scientific Method

2). (4 pts) The figure below shows the steps of the scientific method, labeled (i)-(viii). Which of the following options are true? You are assumed to know the identity of these steps for this question. In two cases, you are asked to relate the elements of this figure to demonstrations done in class. (MTF)

(A) “Data” are part or all of (iv) and (viii). Yes, (iv) is ‘data’ and (viii) is ‘more data’, from the figure in class and book

(B) What we refer to as the scientific method includes all steps but (i) False; no step can be omitted

(D) For the in-class demonstration using the “Wheel of Fortune” game, your guesses at letters in the blanks were examples of (ii). True: the guessed letters were models of the actual letters

3. (5 pts). Which institutions or processes were described as (usually) lacking at least evaluation (and perhaps other elements)? MTF

(A)

religion

(B)

evolutionary biology

government agencies

(D) the criminal

justice system

(E)

car repair

(F) writing a news

article

Straight out of the book and lecture, except that option (B) was not discussed, so it cannot be considered an example of something that was described to lack evaluation. (A) and (C) were the only two described as lacking evaluation.

4. (5 pts) David is writing a computer program GOAL[[to determine all whole numbers between one and a billion (10⁹), which when multiplied by 3, give a palindrome]] (a palindrome reads the same way forward as backward). The first 10 of these numbers were given to him by someone else, but there are possibly hundreds or thousands of numbers satisfying this criterion. He starts out by writing MODEL [[a simple computer program]]. EVALUATION, DATA IMPLIED [[It fails to generate even his list of 10]], so he looks closely at the program and discovers that the program approximates numbers rather than treating them as exact values. REVISION[[He fixes this problem]]. DATA, EVALUATION[[Now his program correctly provides his list of the first ten palindromes plus others]]; EVALUATION[[these others are correct solutions to the problem]]. EVALUATION[[But the program has another difficulty]]: DATA[[the program stops considering numbers at 10⁸]], so David still does not know the palindromes between 10⁸ and 10⁹. After calling a friend for help, neither of them is able to solve the problem. The program remains unfixed, and David has an incomplete list of solutions to his problem.

Which elements of the scientific method are present for use of this program to find the numbers? MTF

(A) Goal

(B) Model

(D) Evaluation

(E) Revision

(F) None

5. (5 pts) Astrologists claim to be able to predict your future and give insights to your being, and they have well-defined rules to use in reaching those forecasts, based on your birthday and birth hour. However, there are no attempts to test the accuracy of those predictions – no formal observations, no comparisons of observations to predictions, and no consequent changes in the rules used.

Evaluation is absent in this description. Why? (the underlined phrase is the goal) MTF

(A) Revision is absent, and there can be no evaluation without revision. False: first part is true but second part false: a lack of revision does not imply a lack of evaluation.

(B) Models are absent, and evaluation involves comparing a model with data. Without models, evaluation cannot exist. First part is false, so the option is false as a consequence.

(C) The problem states that there are no attempts to test the accuracy of the predictions; this statement directly indicates that evaluation is absent. True in both respects: the statement does indeed say there are no attempts to test predictions, and this describes a lack of evaluation.

(D) Data are absent. Without data, there can be no evaluation. The first part is true because the statment indicates ‘no formal observations.’ The inference in the second part is also true.

6. (5 pts) Many government agencies are established to promote the social good in specific ways. Our government goes to great lengths to establish guidelines for how these agencies operate, how money is allocated to them, and their relationship to/overlap with other agencies. These governing rules even change occasionally, typically dictated by elected officials with political agendas. However our government does not have in place any formal procedure for gathering information to assess whether an agency is achieving its specific objectives.

Which of the following points about the scientific method are true, based on the above description? The underlined phrase consists of the goal for this problem. (MTF)

(A) All elements of the scientific method are present in the above description. False: data and evaluation are absent by virtue of the claim that the “government does not have in place ... objectives.”

(B) At least one element of the scientific method is absent from the above description. True by virtue of the answer to (A)

(C) Revision is indicated by “rules even change”. True, although someone challenged this on the grounds that ‘revision’ only applies when stemming from an evaluation.

(D) “guidelines” constitute models for this goal. True. You need to be able to understand that ‘how these agencies operate’ is a model for them operating to function in accord with the reason they “were established.”

7 - 11 (7.5 pts total, 1.5 pts each; one answer only per question). In the class book, the process of designing advertisements was said to resemble the scientific method. Which steps from that example illustrate each of the five elements of the scientific method?

Use these 5 answers as your list (A) current and modified ads

of choices in 7-11 below: (B) deciding which ad most closely achieves the goal

(D) adopting the ad with most responses for general distribution

(E) responses to each ad in trials

7. Goal: (A) (B) (C) (D) (E) (one answer only)

8. Model: (A) (B) (C) (D) (E) (one answer only)

9. Data: (A) (B) (C) (D) (E) (one answer only)

10. Evaluation: (A) (B) (C) (D) (E) (one answer only)

11. Revision: (A) (B) (C) (D) (E) (one answer only)

You should be able to reason through this, but it also comes straight out of the book.

12. (5 pts) Which of the following statements apply to our teachings of the scientific method or were given in class or the book as illustrations of a failure to adopt scientific evidence? (MTF)

A) Models and evaluation must be closely tied to goals to be useful in the scientific method. True: a point made throughout. Change the goal and the limitations of the model change.

B) Simple endeavors involving “trial and error” have the basic elements of the scientific method. True: the analogy is in the book and lecture.

C) South Africa’s policy on treatment of HIV infections has, at least until recently, discouraged the use of antiviral drugs. Yes, given as an example of failure to heed the scientific method.

D) Muller’s discovery (at UT) that X-rays cause genetic damage was rejected for several decades. No. This example was not mentioned this year and probably not mentioned last year. If it was not mentioned, consider it false on the grounds that it ‘was NOT given’ ....

E) Lysenko’s political influence (in Russia in the 1950s) opposed the science of genetics and led to agricultural disasters True, as given in class.

F) The book suggested that the strategy used when gambling with a slot machine did not allow improvement via the scientific method, whereas some types of gambling with cards did allow improvement via the scientific method. True. You need to have looked at the end of Chapter 3 for this.

Models

13. (4 pts) Demonstrations. Lecture used some demonstrations and topics to illustrate the scientific method and others to illustrate models. Indicate which of the following demos or topics were used to illustrate (some aspects of) models. If a demo or topic was not used in class, or if it was used to illustrate the scientific method, do not fill it in. MTF So far, only (D) and (E) were used in class. In 2006, mice were also brought in. Both (D) and (E) were used in conjunction with models. The demos using the lamp and Wheel of Fortune were used for the scientific method but not included in the options here.

(A) Spinal Tap video

(B) mice

(D) Breathalyzer

(E) slogans

14. (5 pts) A theme is that all models are false. Which of the following are consequences of or fixes for this principle? (A flaw of a model is merely some way in which it is false.) MTF

(A) We recognized 3 properties of models, ACU (accuracy, convenience, uniformity), because each model has only one of these properties. Each goal needs one model with each property. The two underlined phrases/clauses are both false.

(B) Scientific progress is defined by finding models that have fewer false properties than their predecessors. No, we don’t ‘add up’ the false properties of models. It’s a question of whether the ways in which they are false matter much.

(C) Flaws in a model do not necessarily create problems for scientific progress because of a “2 wrongs make a right” principle – multiple flaws in one model cancel each other. Again false. We made no such claim.

(D) One way to overcome a model’s flaws is to gather data that avoid the flaws. We did not discuss ways to overcome a model’s flaws, only to find more useful (better) models.

15. (5 pts) General points about models. Which of the following are true? MTF

it is possible for the same model to be useful for some goals but useless for others Absolutely, a point made many times
for any given goal, there are usually many different models Yes, as exemplified by the ‘one-to-many’ and ‘many-to-one’ principle and the fact that we have different types of models.
a model cannot be both accurate and convenient False: counterexamples to this were given
if a model is useful for two different goals, then if it is accurate for one of the goals it is also accurate for the other goal Sounds good, but no such luck. Mice are useful models of humans (for genetics purposes) and useful models of other mice. They are perhaps accurate models of other mice but not accurate models of humans (even at the genetic level).
the convenience of a model may change over time Yes. When the polio vaccine was developed, tens of thousands of monkeys (and many chimps) were killed in testing and for tissue cultures to grow the virus. Now it would be prohibitively costly and perhaps ethically unacceptable to do that work
A precise mathematical model in which all the terms have been assigned their correct values is considered an exact model of the process it represents. False, by virtue of the simple point that no model is exact.

16. (5 pts) Each of the following options compares two models for a particular goal. Bubble options in which the first model (in bold) is more convenient than the second model (underlined) for the goal. MTF

(A) The airburst test instead of volunteers in tests of condom integrity during sex. Using a machine to test condoms is obviously more convenient than using humans.

(B) Yeast instead of mice in tests of whether chemicals cause cancer By virtue of the size of mice, cost, and ethical issues, yeast are more convenient.

(C) Humans accidentally exposed to toxin instead of humans deliberately exposed to the toxin in testing the toxicity in humans Ethics makes the latter unacceptable

(D) Long term studies of a pesticide versus short term studies of it fed to rats for testing whether traces of the pesticide in food cause cancer. Short is always more convenient, though not necessarily more accurate.

(E) A bomb detonation versus a computer simulation of the detonation done in 2 hours on a desktop computer as a measure of the bomb’s yield. The computer simulation is more convenient, although circumstances may affect this comparison. In 2006, we actually discussed an article about nuclear bombs that set the context for this question.

17. (5 pts) Mark all statements that specifically illustrate the concept that there can be more than one model of any particular object or idea (MTF).

A) People’s web pages often include pictures, resumes, and statements about their interests and activities so that readers get good insight to the person.

B) All condoms are tested electronically and all lots are tested with the airburst test before they can be sold.

C) Four different versions of each exam are prepared for the class. Each student gets only one version, but the grade thresholds are the same for each version.

D) Our government extrapolates from rodents to estimate a chemical’s risk to humans, because the number of people exposed to the chemical is too few to rely on just human data.

E) All models are false.

F) The first four clearly describe and/or imply multiple models. (E) may require some thought, but there is nothing about falsity per se that implies multiple models.

Condom testing

18. (5pts) Which are true of the airburst test as a model of condom integrity during sex? (MTF)

A) It is a model of sex between people Yes, and we went over this in class as a practice question.

B) Since the airburst test is considered useful (because it is used by our gov’t), it means we do not accept any limitations of the model. No. Utility is despite limitations (falseness).

C) Studies used it to determine that condoms are somewhat effective in blocking HIV transmission No. Volunteers were used for this.

D) It was used in class to show that baby oil causes deterioration of a condom If you were in class, you presumably remember the comparison

E) Is considered convenient and uniform but not accurate True, as given in the table during lecture. Presumably you could at least figure out that the airburst test is not accurate.

19. (5pts) Class and the book noted some studies in which volunteers were used to test condom effectiveness in blocking HIV transmission. Which of the following apply? MTF

A) The goal in the volunteer study was not the same as the goal that applies to the airburst test of condom integrity This option could be worded better. The goal of the airburst test is to determine whether a condom will hold up during sex; the goal of the volunteer study is to determine if condom use inhibits HIV transmission. At this level, the goals are different.

B) A main potential limitation of using volunteers (a lack of uniformity) was overcome in this case by training the study participant. No, there was no training.

C) The study used single, HIV- men and observed the rate of conversion to HIV+. A limitation of this study is therefore that it may not apply to couples, because single men may have different exposures than those in a relationship. No, the studies used couples.

D) Inconsistent condom use was associated with an approximately 50% HIV infection rate. No the number was near 10%.

20. (4pts) For which of the following goals in condom design is the airburst test a useful model (not so flawed that a condom’s performance would be uninformative)? MTF This question requires an understanding of the airburst test and a sense of what it means to be useful. The point of the question is to reinforce that the importance of limitations (hence the usefulness) depends on the goal. The only ‘true’ option is the first. All the others are not addressed by how much air a condom holds.

(A) breakage during sex

(B) blocking sperm passage through the walls of the condom

(D) An absence of small holes/pores

(E) Thin, flexible, and durable

DWI testing

21. (5pts) (MTF) Which of the following limitations apply to the SFST (standardized field sobriety test) as a model of driving impairment? The statement must both be true and identify a limitation. MTF

A) The SFST lacks baseline data (performance when sober) for each person True, as noted in class

B) The SFST does not address mental faculties False; the person’s ability to follow directions, and perhaps the HGN, are measures of mental faculties.

C) The SFST is affected by many factors not related to coordination, such as a person’s build, their shoes, etc. Yes. also noted in class but easily inferred.

D) As shown in class, BAC measured in breath may differ from blood alcohol concentration Although shown in class, it is irrelevant to the question

E) Scoring of the SFST is somewhat subjective. True, another point given in lecture and easily deduced as well.

22. (3pts) Which limitations apply to using blood alcohol concentration (BAC) obtained from blood as a model of driving impairment? The statement must both be true and identify a limitation. MTF Since BAC may be legally measured in blood, urine, and breath, you need to focus on bood.

A) As shown in class, BAC measured in breath may differ from blood alcohol concentration No, since this limitation of breath only applies to a breath sample

B) Different people may be differently impaired at the same level of BAC. Yes, this is a limitation of BAC as a model of driving impairment and applies to any measure of BAC.

C) The test does not measure impairment per se. True. The statement is true, and BAC (from any source) does not measure impairment per se.

Infectious Disease

23. (4pts) The basic reproductive number (R₀) is a model of the spread of an infectious agent in which ways? (MTF)

A) It describes how many new infections an infected person is likely to cause (while the disease is still rare in the population). True. Statement = the definition of R₀ and also explains something about disease spread.

B) It is an approximate “birth rate” of the disease. Yes, as given. If you understood (A), then you could figure this out, as well.

C) It indicates how feasible it will be to eradicate a disease with a vaccine Yes, but this you probably would need to know from class.

D) It is easily measured over a wide range of environments and typically shows only a small amount of variation (different estimates vary by less than 10%) No. I don’t care if you remember the numbers for each disease, but one point made was that this is a limited model because the number depends a lot on the environment; the variation is often quite large.

E) Values for common diseases are usually between 1/2 and 1. No. If you remember the epidemic threshold, you would realize that the value must exceed 1 if the disease can spread. So if the values were less than 1 (or even 1), they would not be ‘common’ diseases.

24. (5pts) The epidemiological model presented in class and in the book (involving the number of infecteds, susceptibles, transmission rate, etc) is both a useful and false model. Which of the following options is correct. Each option is prefaced by indicating whether the sentence describes a reason the model should be considered useful or false. (MTF)

A) Useful model. The model can be applied to all sorts of diseases, including sexually-transmitted ones, and those that are transmitted to humans from non-human species. Nope. We said that the model did not apply to STDs for example. It also doesn’t work for animal to human transmissions.

B) False model. The model assumes “mass action” whereby a person’s chance of getting the disease does not depend on where they live within the population. We noted the ‘mass action’ assumption as a reason the model was false. So the option is correct. I should no doubt word these in a less confusing way.

C) Useful model. The model provides values for how large a fraction of the population needs to be vaccinated (immune) to eradicate a disease. Yes, that is the main purpose of the model.

D) False model. The model neglects whether infected individuals recover from the disease. No. If the model did neglect recovery, that would be a reason it is false, but recovery rate is it.

25. (4 pts) Which of the following points were made about influenza (flu)? You may defend your answer with the book, class lecture notes, or any other valid information you have. (MTF) Sorry, mostly just facts here.

A) Influenza is caused by a virus that infects the respiratory system. Yes

B) Vaccines need to be updated because flu virus evolves over time to escape our immunity. Yes

C) The R₀ (basic reproductive number) of bird flu (H5N1) is currently less than 1 when it jumps into humans. We barely made this point this year, but if the basic reproductive number was greater than 1, bird flu would be among us.

D) In two years, the 1918 flu killed about 10% of the number of people who have died from AIDS in the last 20 years. I forgot to mention this in 2007 (so far). It’s not true, however. AIDS deaths worldwide now exceed the 1918 flu deaths.

E) There were 3 flu “pandemics” in the 1900s, in which a new H-type of flu jumped into the human population and spread throughout the world. Yes

26 (4pts) Key code. Fill in AB on your scantron to indicate which version of the test you have. Correctly bubble in your Box number and name, and sign this form. Note that you get 4 points for doing a few mindless tasks correctly. And you don’t get 4 points for neglecting them or doing them incorrectly.