Chapter 1. Chapter 1: Process of Science

1.1 Introduction

Interactive Study Guide
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Polaris Trail

Welcome to the Interactive Study Guide for Chapter 1: Process of Science! This Study Guide will help you master your understanding of the chapter's Driving Questions, using interactive Infographics and activities, as well as targeted assessment questions. Click "Next" to get started, or select a Driving Question from the drop-down menu to the right.

Java Report:

Making sense of the latest buzz in health-related news

DRIVING QUESTIONS

  • How is the scientific method used to test hypotheses?
  • What factors influence the strength of scientific studies and whether the results of any given study are applicable to a particular population?
  • How can you evaluate the evidence in media reports of scientific studies?
  • How does the scientific method apply in clinical trials designed to investigate important issues in human health?

1.2 Driving Question 1

Driving Question 1

How is the scientific method used to test hypotheses?

Why should you care?

When we understand how science works and how scientific evidence is obtained, interpreted and refined, we can analytically and critically evaluate the findings we read about in the media. Then we can make good, evidence-based decisions about our lifestyle choices rather than following the latest fads.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. Describe and discuss the process of science from initial observations to publishable results.
  2. Compare and contrast the conclusions generated by rigorous scientific study and those generated anecdotally.

Question Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term Definition
ITcKvaOmxWiOKiRuKPSM+LmQ3rZThg0UzTJ2EFDM4jNe5AgpvN7qi3hFYmaf0G+3F1+l6wgo7Aynw0D4S5NGWFD/r5qtSkaPKvWkXkJBhK7FI/Ye+4ag2Q== An informal observation that has not been systematically tested.
F7nshK+M2gSZPxl6HSQMs9MsgWaBZVQ8BjVYyfIg9+f1FMvsuBobMJ1xShDox+YVXKdS1kTXhuj3fshg+lK+/ToQA90AtPrKzT8l3txqQOwhKDp588BHnw== A tentative explanation for a scientific observation or question.
eMo6SzxC3YKh3qyzcfP9kaKa4ApNy55IPW0BbK/qnkLUTXw7Ldq+RpBes5sbT+BUD47OzpB22T2MoktD18q9gL8k6sEWnYomNckC7LjXP+QlyWidTudSFw== A carefully designed test, the results of which will either support or rule out a hypothesis.
5GbJ2lG6vOIASM7tTgJr3IU2nZvcQNtNrnI2ZXXqf3WNHy1rsWvIAFzslxsFJ53AKCZ1DA7qvMi7oiD/DM9tw9Hp32k68OlwiefJilr6d1rDO+X0SXJe8w== A process in which independent scientists read and critique scientific studies before they are published to ensure that the authors have appropriately designed and interpreted the study.
mOvkgbPVHCCqwuMA40szaBzo1+iL62YDlAYTjA3vlN+5CWc60bLglNbrw+ithAQ7vJfNfedQW4cdzjPvyO4mQJpUTzOBfWQNhqfmvbPM9Atw7cfSJ7qR1w== The process of using observations and experiments to draw conclusions based on evidence.
T9CgTUZGdgUZiua0LjFBoX2R6HvW1psqnU4UtoYYnrsPQTRHpwjTdx4QO2Pzf8046i3kB2VhVERLeFH/ExdkBCghoF7as5zFd59dnYl8AL80VPoKlW7Ocw== (A hypothesis) demonstrably ruled out by data showing that the hypothesis does not explain the observation.
dSfb4HNrXALFpF0VBUKQRBq85exMuG+kRGD6aeYmNxcoCg3WAvunVK9K3LLFO1HXqsb69fYuPvwqbCa/s/qBG6XNN1y389LJg+ApgNagJh+3EH9oX5HvOA== Subject to support or rejection (of a hypothesis) according to carefully designed experiments or observational studies.
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Describe and discuss the process of science from initial observations to publishable results.

Question 1.1

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Generally, an initial observation leads to questions about the observation, for example, the observation that a certain species of squirrel tends to bury acorns in the fall. Questionsconcerning this observation could include these: Why do the squirrels bury the acorns? Do they bury them all in the same place? Do they bury other things besides acorns? What happens to the acorns? The next step in the scientific process would be to pick a question and look in the scientific literature to see if anyone has asked that question before. It is possible that the question has not been addressed by other researchers or that an aspect of the question was addressed and the results were reported. Either way, if the initial question is novel, either by itself or building on research that has already been performed, a hypothesis can be formed. A hypothesis is a testable explanation of the initial question. Staying with the squirrel/acorn example, if we chose the question ‘Why do squirrels bury the acorns?’ one hypothesis could be, ‘Squirrels bury acorns in fall so they have food reserves for the winter.’ The next step in the process is to test this hypothesis with experiments. For example, the location of the buried acorns could be monitored throughout winter to see if the squirrel comes back, digs up the acorn, and eats it. After analyzing the results of the experiments, you will be able to either support or reject the hypothesis. If the squirrels do not come back to the location to eat their buried acorns, this is evidence that undermines[k1] the initial hypothesis. At this point, another new hypothesis could be formed based on what you learned in the previous experiments, such as ‘Squirrels bury acorns in the fall to grow more trees to build nests in,’ and the testing could continue. If, however, you were to find that the squirrels did come back and eat their stash of acorns, this would be evidence that supports your initial hypothesis. Your results could then be published in the scientific literature for other researchers to use to formulate their own hypothesis or to retest yours.

Question 1.2

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The steps of experimenting and analysis of the results should be repeated several times and in several different ways (usually by different scientists) if the hypothesis is to be rigorously tested. This will strengthen support for the hypothesis if different researchers using different techniques can all come to the same conclusion. This process reduces the chance that the data supporting the hypothesis are in error due to mistakes made by one scientist or technical failure of a machine needed to do one particular test.

Compare and contrast the conclusions generated by rigorous scientific study and those generated anecdotally.

Question 1.3

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Anecdotal evidence is an observation that is not supported by any scientific testing. For example, after I drink coffee, I notice that I am sleepy. Therefore, I believe that coffee makes people sleepy. On the other hand, I could also say that after I drink coffee, I notice that I am energized. Therefore, I believe coffee makes people feel energized. Both are example of anecdotal evidence because they are observations and data collected from only one individual and therefore shouldn’t be applied to many individuals.

Question 1.4

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The difference lies in the quality of evidence supporting the conclusion. With rigorous scientific study, many people have studied and performed different experiments based on the initial observation and hypothesis and have all arrived at the same conclusion. With anecdotal evidence, it is typically the conclusion from one or even a group of people based on no scientific study or testing. Most of the time, anecdotal evidence is based on personal experience, which would be a fine way to start the scientific process—by asking questions about that experience.

Review Questions

Question 1.5

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Question 1.6

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Question 1.7

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Question 1.8

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1.3 Driving Question 2

Driving Question 2

What factors influence the strength of scientific studies and whether the results of any given study are applicable to a particular population?

Why should you care?

The strength of a scientific study’s conclusions depends on the quality of the study’s design. Controlled experiments are one of the most powerful tools scientists use to test hypotheses. Understanding the characteristics of a good controlled experiment helps us evaluate the conclusions we read about in media reports. Sample size is also a critical component of good research design. Typically, conclusions from studies with small sample sizes are only weakly supported. When you read media reports, one of the first things you should look for is sample size; if it is small or if it is not reported, you should remain skeptical about the reported conclusions.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. Compare and contrast the control and experimental groups of a controlled experiment.
  2. Describe the design of a controlled experiment.
  3. Illustrate and discuss the significance of sample size on the strength of conclusions drawn from scientific studies.

Infographic Focus

The infographics most pertinent to the Driving Question are 1.3, 1.4, and 1.7.

Question Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term Definition
QXqcYJ9abI9b6zRsX9eDvjpKBJpYzV1uqEZUy4rkFzP9X55PuwfZEGdmP5Q5r4bZkrq4zsAepKi2ubGItFcFQ+bNFY1S480KKk/VX3QbRfZg2jAanPsXlXpnmbzIIbr49/weS1DeaPd6Z3V09M3lMpE2kuZYcNrT492FEA== A fake treatment given to control groups to mimic the experience of the experimental groups.
EmoKzEmGE9/K9zVasNWwsu9osmrO7d5qSELlGPUDZzKGVaII+udGuBV/zizi7Ok52SidBfTk0HiH7hqLOe2w2hK8paFduih/syH1cq671sF+dXJLh13qchflHwu92j5ICkQUA9U3R4nyORYMgOEypYXmUB4cnFK0OIAQfw== The measured result of an experiment analyzed in both the experimental and control groups.
K4Xe26/MBqhelAwEaHZY/uRk3v1srMZBQInt19R8f4TxEL8/rKxR5ZF199iqQtLp6/b3xmvgshewzNom0Ljyij/VW3EWOt6S8nWcLO3MkqggZ9OVBfcT5RJN5SG7TWP7N42D78KajqPkzBCH7F5jIN+DG/tbzWN5+6n02g== The group in an experiment that undergoes the experimental intervention or manipulation.
IOMUzThJEN3L9nPrFMHOmTgFtnoJ+jfuH5kxttpThuesTL0hgyT4J/s+CP/AH/jnW/U0+zNzoL/Y0A2X6UUVa+MxHib2RRCJg88MKPtL01RjVb0mBAa1a/AqVEBJstSyc2z7zFe2mbIm8QJ81xN2t/s2Zlj3V6sRhP+U5A== The group in an experiment that undergoes no experimental intervention or manipulation.
y4P+UhszyJWUHM+xsDZkM94WM27impBsVjxJ6xmgcV17Il0wApo61a/Y3mUR5XjMjB0kigj2u0PrghX7Sk/sJeW4L6WP2/WL52EmZeFTkUiuB+XfmKLaS2tyzzJUw6vucuzrcS1juigdMHv4TC2mX/W1snPVZdVrWOorPw== The variable, or factor, being deliberately changed in the experimental group.
2ArZ9q1FxAp6QGM1JfVG0A9UUy/tiAWqC+sqkJyFpir1hwYFwdsSrXipRXYoZGAmI/9/35ZLinD8FXbqn8jW7lTLiMOc+E4sG4LSuqXmV2WjIOeaB/WG3E7cx+MGD+fnofsCGNlK3IhR1nICLDjKtGfR1h/183+hkC9XhQ== A measure of confidence that the results obtained are “real” and not due to chance.
l8GwbDrA5XzC2b31I8Ee93YT4KX+89Dn0EzmIoAcmsf8nEpRnwLN4CVUcO43MZw7FFFnCaQOI1J12xt+V6U3a+W6XYltDUjWYq0E2rafqN9BtiL2+NJMfgYUElY7TkQ9Q06/0aTYlJ9GivIGtRMoAfi6CGad/GV4D/VXlw== The number of experimental subjects or the number of times an experiment is repeated. In human studies, sample size is the number of participants.
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Compare and contrast the control and experimental groups of a controlled experiment.

Question 1.9

Lee Ryan began her coffee-drinking study with a sample population of 40 men and women over age 65, divided into two groups.

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Similarities
- Adults all over 65 years old
- Groups equally composed based on gender, health, and activity level
- Both given 12 ounces of beverage to drink 30 minutes prior to memory test
- Both given memory tests in the mornings and afternoons of different days
Differences:
- Control group given placebo (decaffeinated coffee)
- Experimental group given treatment (caffeinated coffee)
- Afternoon memory test scores the same as morning test scores in the Experimental group
- Afternoon memory test scores worse than morning test scores in the Control group

Question 1.10

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The similarities are important because the researcher wants to know the effect of caffeine on preventing memory loss. To do this, she had to make the groups as similar as possible so that they could be compared. If the groups were unequal, say one group was made up of males and the other females, the scientist would not be able to tell whether any differences observed in the memory tests were due to caffeine or gender.

Question 1.11

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The differences are important because it is what the researcher is actually testing. In this case, the difference between the groups was whether or not they had caffeine in their coffee. Since all other variables were controlled for (e.g., age, gender, health), any differences seen in the memory test scores could be attributed to the presence or absence of caffeine.

Describe the design of a controlled experiment.

Question 1.12

Describe the experimental design of Dr. Ryan’s coffee drinking study by answering the following questions.

BpOiQacD41bN7rXvNxEVk6pJ1fU1Ef9GmckOIUEj4Eh2pKH5Nm7New==
Caffeine

Question 1.13

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The treatment for the experimental group was 12 ounces of caffeinated coffee. The treatment for the control group was 12 ounces of decaffeinated coffee.

Question 1.14

JmtA/RYk2N8bOQMQLP6UDgrOTkcNljJP6Z10atPE4o305k9vBnFjK9ic+Zd4T/XnwxLN8w==
The participants did not know whether they had received the caffeinated or decaffeinated coffee prior to the memory test.

Question 1.15

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The memory test.

Question 1.16

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The dependent variable was measured using a memory test. It was not measured differently in the control and experimental groups because the researcher wanted to make sure that any difference in memory test scores was due to the independent variable (the caffeine) and not how the test was measured.

Question 1.17

Describe the significance of using good experimental design by answering the following questions.

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No, because then she would not have known whether differences on the memory test between the two groups were due to caffeine or the other differences between the groups.

Question 1.18

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No, because people in the control group might have performed better or worse if they knew they had not received the caffeine.

Question 1.19

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Again, no, because if she had measured the control and experimental groups’ memory tests differently, there would be no way of knowing whether the differences seen when comparing the results of the tests were due to caffeine consumption or due to the way the test was measured.

Illustrate and discuss the significance of sample size on the strength of conclusions drawn from scientific studies.

Question 1.20

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For the first graph, increased consumption of caffeine slightly increases performance on memory tests. For the second graph, increased consumption of caffeine greatly increases performance on memory tests.

Question 1.21

The following table contains hypothetical data from a study of the effects of caffeine consumption on a test of short-term memory in college students.

Participant Caffeine (mg) Test Score (points out of 100)
1 0 20
2 50 30
3 100 60
4 150 100
5 200 100
6 0 55
7 50 70
8 100 45
9 150 50
10 200 40
11 0 60
12 50 40
13 100 35
14 150 40
15 200 45
Table
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Increased consumption of caffeine greatly enhanced performance on a short-term memory test.

Question 1.22

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Increased consumption of caffeine slightly enhanced performance on a short-term memory test.

Question 1.23

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In the first data set and graph, the more caffeine individuals had, the better they performed on the short-term memory test. In the second data set and graph, the correlation between increased caffeine consumption and memory test scores did not remain. Some individuals in this group had a high level of caffeine but did not perform well on the memory test (for example, individual #13).

Question 1.24

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The larger the sample, the more likely you are to see all of the possible outcomes of your experiment. If you used only five people in your study on caffeine and short-term memory, you would have concluded that there was a strong effect of the caffeine. Based on the results from the larger group of 15, this finding would have been inaccurate.

Question 1.25

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The larger the sample size, the more likely you are to see all of the possible outcomes of your experiment. If you only used 5 people in your study on caffeine and short-term memory, you would have concluded that there was a strong effect of the caffeine, which, based on the results from the larger group of 15, would have been inaccurate.

Review Questions

Question 1.26

Use this scenario to answer questions 26 to 28:

You wish to test the effects of energy drinks on short-term memory in college students. You recruit 100 volunteers for your study. The control group will receive a placebo and the experimental group the same volume of Red Bull. You will administer a test of short-term memory 30 minutes after participants consume their drinks.

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2
Try again.
Correct.
Incorrect.

Question 1.27

w7AFfdMncet27VOHIo/tNfk0pfJmAkjgtuL0PWlOPcK5F7i/mkkVh3NFXpxXsXVzgtjChJcPjFedUulOdL/GwGx5s8ErGqofvrkvNub9BpKh4BKgELTlOGa3a5GlNUPDb1PZziXfx6bCA0lBza78CMp4EEs84jA5VdH3YarNQcXLgQ4fQlXAB3wIvTHcYsRs0CdjIs+90bJzsDiyELpH6Svj3zONdd9zSY70RLQ4a6/u6wApmlnhZ6MzOtOKrlDWJhCHeCLV/r5qEgvzF29cKqb3EURbXEFyx73Kgo8vRJ/aPftBh8dYjiwnrEDBK882sWlCVuMzwaILvMk9fMBqdYrxyptW8XECYt9tFXsTssN6dTj9Jt9U1tcHDTF2SUURB9baGwMzqRUG96/2ai+91prtwt8LJtJjYZBjSQ==
2
Try again.
Correct.
Incorrect.

Question 1.28

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
2
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Correct.
Incorrect.

Question 1.29

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
2
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Correct.
Incorrect.

1.4 Driving Question 3

Driving Question 3

How can you evaluate the evidence in media reports of scientific studies?

Why should you care?

Most of us are not health care professionals. Lacking the knowledge and skills to read, understand, and synthesize all of the scientific literature about human health, we must rely instead on media reports to stay informed of the latest findings and trends. We cannot, however, take those reports at face value. We need a proper understanding of the process of science to critically evaluate what we read and to use what we read to make good decisions about our own lifestyle choices. Understanding how and why important details may be missing from media reports is the final piece to helping you become a critical and analytical consumer of scientific news.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. Compare and contrast the everyday and scientific meanings of the word “theory.”
  2. Explain why a correlation in a scientific study does not necessarily indicate a cause-and-effect relationship.
  3. Explain why media headlines may not accurately convey the results of scientific studies.
  4. List and describe the questions a skeptical consumer should ask about a media report before accepting the reported conclusions at face value.

Infographic Focus

The infographics most pertinent to the Driving Question are 1.2, 1.3, 1.4, 1.5, 1.7, and 1.8.

Question Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term Definition
VeAXJKvdYdO1wtgQNY1bGVSGX1GTwivM28u2+HSjATaJbl6RXaWXc1ZPO5DanXGRRoQx7PJONWL87k9w/LKI0g== A controlled medical experiment in which subjects are randomly chosen to receive either an experimental treatment or a standard treatment (or placebo).
SyyxbYi1cPhc14IZ4uSfDlRQ7JtRsJjaxzt/o+zqr+evSBZ+TkY+/vdbO6ywahHKloQJpSeHsrGEM4eP61AMjg== An explanation of the natural world that is supported by a large body of evidence and has never been disproved.
eJe0D0zH8POlRzr0ggSUXOOWJyiTl01cy47JxdQ2+4FktRLgPJKl/h67+PeafVYTFmvOVnm2bjO/uJaz++KPWg== A consistent relationship between two variables.
Table

999
Try again.
Correct.
Incorrect.

Compare and contrast the everyday and scientific meanings of the word “theory.”

Question 1.30

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They are similar in that they attempt to explain an observation. For example, one scientific theory explains why populations of organisms change over time and one everyday theory explains why it doesn’t rain sometimes.

Question 1.31

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Theories are different, in the evidence that supports them. A scientific theory has been rigorously tested by many, many scientists, in different ways, typically over many years (sometimes even centuries!) and has never been disproved. An everyday theory, on the other hand, has no scientific evidence to support it; often it is an individual’s observation and has not been tested in any way.

Explain why a correlation in a scientific study does not necessarily indicate a cause-and-effect relationship.

Question 1.32

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There is no strong evidence that caffeine causes a reduction in the risk of developing Parkinson disease. The evidence presented in Infographic 1.7 is flawed in many ways: the experimental group studied is Japanese-American men and results from this group may not match results that would be obtained from a different population, say African-American women. There is no control group, so an absolute causation statement of caffeine reducing the risk of Parkinson disease cannot be made. (Rather, there is only a correlation between more caffeine intake and less risk of Parkinson.) The other variables in the group, such as stress, whether or not they had children, and location of home, are not controlled for, so it is possible that one of these factors may also be playing a role in the lowered risk of Parkinson disease.

Question 1.33

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A correlation is simply a relationship between two observations (like increased caffeine use and lowered Parkinson risk), while a cause-and-effect relationship states that one thing is responsible for the other (like caffeine consumption improves memory in adults over the age of 65). A correlation between two things does not imply that one thing is a result of the other; rather it just says that there is some relationship between the two.

Explain why media headlines may not accurately convey the results of scientific studies.

Question 1.34

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Media reports cannot contain all of the complex data found in scientific studies because there is not enough room in the paper and the reporter likely does not have enough time to fully comprehend all of the subtleties that scientists train years for to understand. Also, media reports tend to be sensationalized to sell. An article stating, “Cure for Parkinson disease is found!” will likely generate more attention and sales than one stating “Caffeine consumption is linked with a decreased risk of Parkinson disease for a subset of Japanese-American men living in Hawaii.”

List and describe the questions a skeptical consumer should ask about a media report before accepting its conclusions.

Question 1.35

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Who performed the study?
Did it have proper controls?
What was the experimental group? What was the control group?
Were all variables taken into consideration?
How were the experiments performed?
How were the data analyzed?
What do the data suggest?
Look for yourself; do not depend on someone else’s interpretation of the data, unless that person is a trusted scientific source.
When in doubt, talk about the study to someone who is familiar with the discipline or area of research.
Go straight to the source!
READ THE ORIGINAL RESEARCH PAPER the article is based on.

Review Questions

Question 1.36

“I feel more cheerful when I wear bright clothing therefore bright clothing makes people more cheerful” is an example of a(n): (mark "true" for all correct answers)

a. scientific theory kn+fKbLB8wAnmZ3XQAUvWA==

b. everyday theory 2YvaXR/y8mhoD5Q0hHYKqg==

c. hypothesis 2YvaXR/y8mhoD5Q0hHYKqg==

d. data kn+fKbLB8wAnmZ3XQAUvWA==

2
Correct.
Try again.
Incorrect.

Question 1.37

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1
Try again.
Correct.
Incorrect.

Question 1.38

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2
Try again.
Correct.
Incorrect.

1.5 Driving Question 4

Driving Question 4

How does the scientific method apply in clinical trials designed to investigate important issues in human health?

Why should you care?

When you understand the elements of good scientific studies and some of the cautions that you must exercise when interpreting their results, you are better prepared to take information transmitted through popular media and decide, as an educated consumer, how it affects you.

What should you know?

To fully answer this Driving Question, you should be able to:

  1. Use all of the information learned in this chapter to assess the claims and evidence reported in clinical trials.

Infographic Focus

All of the infographics are pertinent to the Driving Question.

Question Test Your Vocabulary

Choose the correct term for each of the following definitions:

Term Definition
H0a+PqxKY3yDOjZEXGl1HlJu4PPlTKH3ieJuTR1fRdkfFpHaamvzpsF7bzXFSSWpMqC29Q9fHut21G9vzbfpE+1NPLR/ONIWR+Y9wf1L3jOzWoiAcJPMa39yutAlzLdiNySd5EgqRuOs2NfDOAk+YrEBdCfduNSZwqDnFY8E/YZI2JD5o8BkGYyt8dnnacUINKBYx/oPBIl/uH+GUasZ34Ma8hkrGvTgNeBi5EdCYBaigRk8LSW+BUuqVIUvi4o+9YHOzkhkezsYj5+W/pFI4ur4WqFIVLmspqGdlAybAYUeNliYnpxeZ9PlakJ2b2JQYn2FtYBYmt9w4Uq7SZiwz85cn/q8QAbLxYSVHdGWX7VU+XSQ Subject to support or rejection (of a hypothesis) according to carefully designed experiments or observational studies.
QSnQ66mkaUjAjqRl1oud68yhcGfKjiqmQE6qvBZ3O4JcB8HChMZAztOwqv9pFGWEcQ+HWoEBO2uU14TtDRlTHi94Fj0asOmV2bu2TeHTzGAjhMNZs+5asEbCMikQeU69Zwq+KL19SOhLFh2P1CR6/JVuCvfOxEuZJlalwqg/qM4650T4/Vio8Hb4Mks7BoBgDL4h9Zw0YqxWyaxqodNlLOeS3X8tKgB2+pZ6XPW82TE5VYGp/w+J3er+vtGdEzHioqRFqamTz6wbSGU8oS+DOH5X2H/4CQp4pHfmalQdFKxGd0NDsjwFSlQi0lK1H+Sdxnn3eB2GnBVnXAf7W53qcLfR7JThkIRt1Lq4NvTddyV4ed3R An informal observation that has not been systematically tested.
Bw6uTZ4APIjzZjI/KXMyWLD4jlZYu+s6h7vWUw08jKevg7VXxuzuZMW5nQxvatvdoFwAhc3WrRY0w1U1ShUiXxNtri09PkJxCPUPLa3iFTj346TI5JPxsEbEcCtH42Zei1Z7BN5bEnjnzLx5aUpDnc5AoFmGl92acepwOyLopX+XXuhZMUVrfw572PXhHyHvfInsf7hAF6gyd+MxgNcp7g5mNBSYA4zpc2TD0CYoealVDBjVkewyE6OW1ECOLfeV6s88wJnavJqVCoJejPpRqnEhlmRAtR1Hn1W2PL9K6uCrIrrDU3AZ3XgNto/iceNBsXvlp+89ejTNTlve5eeVyRALTCACF1RFTMUK8Prkgsa3Gg67 A tentative explanation for a scientific observation or question.
I1Ce9ZlabMw/JKLRhUXHwuIztCKRz736S1LsMfsTTb6c0MbTojr8ZnDtiid2k/cC0WB9HgaAXlssbpTpQ5LWC7EfXoa4DXkLqd+WgHveJtHVeMamxqMxrKl3ByVvEu/1tBuxtGlE7VCn3RjBEJlP8qpHhYd84dnHlvRs2hltxkuWgMPmw0bP6tUDZ3oT9x2wwK5Rw1pQ1874RMyrqibVODJyftJ0iPxFCOAwIhL4kJmQeClj/UR+6YB5I7WU9Ta5dPIAxcXfJXdy/Ev7YTHxZ2zb5gSaXHumpSkf0zTO0MI8925Q3jPldXYocUO85QO124QUhPQrCn9UskEk6pny0MN588haxAWBxJJa7e+wnCnZh9qU The measured result of an experiment analyzed in both the experimental and control groups.
4LG5nV24kBILkd35nAaKWbjirDjtN/69ye22eMOyxu5NZnXUHHd/AVaKw6TiVqaWC1/LIf/zlIAPFVgSdk6sxMKALhwrfNBfob8KoQy10KKnHDWIfFRypb1/IzJPAQBiVpu1rza/LQZ8h5hIeLknFBcyfF6Evv+YZa2nF+sAlDZJyXduk16XkKkSIlgIcElVL4kVnCr9Z6ssx/n4NTkBwDCczVHIMxzpEq896B1t+dIcPdktytobcdzADdBGmNcXPpJs/eog69G34r6TkUeqOxzyxgn6kCRLh1dkHiT+HEafDoED+ECQOXOJ5/+ZQ+Lj+omxUfrgEgV+trbXytK73rx//MYjK/6hGwsHjGJIzDrqL8z0 The group in an experiment that undergoes the experimental intervention or manipulation.
EoinJMCrTQSG3gCmmr4Akj957CzBDxdesGhENN4T4qyQgH+m5S4nqeSEz0awxNsu5CG9dxOxBjbXj9XLtp4clJNv6PnebLkb+tn7eapJok7rgvXSlvVXWFX6BQWpksZzWAoq8Dkbeoc4Dy88S1fCk5YkHI9YIJY71TV7ai8anAQmBZKd79pu8ugDbxZBtu+LnAgZRNSSxGVg9VgoOVcM5IDHfx6BdzNTJZYyKocMJAlF65q8S0zEou5UPGut7kbewlFlrGmoTMDZe8WbB/dIfKihWu9H7qnAZLtNhHNulLpmUosMohBRZZFBBUYmfzUTFSEJ+eyuhHDsNdYGSEyWjYCiROlb2S6jUq7RrfCKFi0852Wb A fake treatment given to control groups to mimic the experience of the experimental groups.
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MXSzbyEgbhNKAh1/sryM47b8sT4eO47X2oiiqJHDr1NiBmi0Ibba8CLF9BGZ+tEd57KFofwiiWqCiR+on8JM0DsYsicqarMFKJNVEFLVJCyRQNpRxY2XL0GOotS8LQ6e0as/f89dZy+fgtnN0mXWkySJHiRBEFvIM9wyHSAlY10oF/Co8nst+iSocwXe4kTnw+leMae7C0Zemiy68km/lSeVf7TCql3FJweRJI9JTRMBCiKllgUPcIxosrTvoOatKng0Q/f9piWvNBPu4uZ3g70sPhXadWCuFVYDY/yckHGC978/Lf4VZk58OiAvTky2wKVAzUJuqlZGTqnFJC2n4PJJeNiZG/+oxn2M/5uceLiBSKrl The number of experimental subjects or the number of times an experiment is repeated In human studies, sample size is the number of participants.
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8ybHlZBLI4J470HB8dqMC2WgzxSvjyOM9wKuA4AKVGaeRy+HSkvU9DRAzz3/eBEot1kawNMNl8r0QD0OkhEuJuEopbB+0Yqf4k3T6/2VNyZICvYWEzWbgH1RDlQGJPrh8IpU9ylPJMJInapsLr085yOs4QwkKcMJbroPNT+f0RIDyEPYnzWN3sNU1RbCrnuJu02OrTlIA+7C4SDCbsqHXmZNZVMJjVnhdUiiMkTsmoSUS4I7ou0oInhR69lyimwCrSxi+DBqoL3UnIsYJ+kHnLneYntLhZRy36oTK4L0LXA/saBu1VoDtUoe1owdRzT/FBVlCWwjZlj0+W+16T5ZhlP0ZERLhf2AvIL5Sr8bW1K76pth The process of using observations and experiments to draw conclusions based on evidence.
Table

999
Try again.
Correct.
Incorrect.

Question 1.39

Read the summary provided as a popular media report of the peer-reviewed article “Insufficient Sleep Undermines Dietary Efforts to Reduce Adiposity” by Nedeltcheva et al. (Annals of Internal Medicine 153:435-441, 5 October 2010) and answer the questions. Note that some questions address the scientific study itself while others address the way in which the study is reported. Both are important!

Excerpt from the Media Report

Sleeping Helps You Lose!

Researchers from the University of Chicago and the University of Wisconsin, Madison, recently reported new findings on the relationship between sleep and weight loss. In a randomized clinical trial, subjects getting 5.5 hours of sleep over a 2-week period lost the same amount of weight as their counterparts getting 8.5 hours of sleep. But subjects on the low-sleep regimen lost significantly more lean muscle and significantly less body fat than did subjects on the long-sleep regimen. Therefore, the more sleep you get, the more body fat you will lose!

Excerpt from the Research Paper

The study examined sleep and weight loss in 10 overweight, non-smoking individuals (3 women and 7 men). Subjects were randomly assigned to two treatments: 8.5 hours of sleep or 5.5 hours of sleep. All subjects were given the same moderately restricted diet, moderate exercise regimen and studied for 2 weeks in a sleep laboratory. Investigators measured fat loss and fat-free body mass as well as several physiological variables related to how the body uses energy. Based on the results, insufficient sleep undermines dietary efforts to reduce body fat.

2+9YsEGGYgEzYBHZJOq3GI4+c2ppX4yP/GDMgiRSz5OqIiKA5I/wUhAUe/4T7IHmVJZHbJ12D/kWL3FxVbyu42gy/R/kfx44CSNLPjLv/6KX3/3p7h0P/vmv9dDxhvXu24Ck52/eaH9LWmWG91Tiv9QBcYgu2A5bihq4jDSoQR2JpQrVDkfO9AlB9boguoF0bqp++RBY9YkvYzY3KqVZDM1OJnPsjiY+x3mzSYjZnHhD5Y880o2nbqMk6N64gp4N9kC73QFEZQ/vjAsq8A2/UWQYfUwW5GsoqNWhpCbgOiTNV0cjcvr9r91QKUP/LyyX1KPIUFnauuEoAjfEX6NOtHdMZyAi5SgU0YbAEKDP+F9NF5qvKdeQPhVt+kvsqRCiyUe1p3aGLwvnfddwImCxb0mgx3tAWQFHs6upRM5BTIYcOiN7MwGGd04wv2wYXL7/Kq1cBiypfbVkhlpa
(a)Question: Does sleep affect weight loss?
(b)Control Group:
Moderately restricted diet
Moderate exercise regimen
2 weeks in Sleep Lab
Weight Measurement: percent body fat vs. body mass
Weight Result: lost more lean muscle and less fat
Experimental Group:
Moderately restricted diet
Moderate exercise regimen
2 weeks in Sleep Lab
Weight Measurement: percent body fat vs. body mass
Weight Result: lost more fat and less lean muscle
(c)Independent variable: length of sleep
(d)Dependent variable: weight loss through body fat and lean muscle reduction
Measurement: weight, percent body fat, and total body mass
(e)Conclusion of media report author: More sleep will make you lose more body fat.
Conclusion of research paper author: Sleeping 5.5 hours per night will cause you to lose less body fat and more lean muscle when reducing calorie intake than people getting 8.5 hours of sleep.

Question 1.40

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The sample size of the study was 10 individuals, three women and seven men. This sample is very small and disproportionate in terms of gender. Nowhere in the description does it say that all subjects had the same starting percentage of body fat versus body mass or the same metabolic rate. The term “overweight” is also used to describe all participants, although the parameters of overweight are never defined. Sleep is also only measured in hours; the study says nothing about the quality of sleep. For example, one participant in the 8.5 hour group could wake up every 2 hours, while one participant in the 5.5 hour group could sleep soundly for the whole period. The stress of staying and sleeping in a sleep lab for 2 weeks would also affect people’s stress level and metabolism differently, so it is hard to say that it was only the length of sleep that mattered in terms of fat loss.
I would not have much confidence in this study based on these design shortfalls.

Question 1.41

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At best, the research paper offers a correlation. There is a possibility that one group contained only male participants (five in a group and seven participants were male of 10 total). If this group was given the 8.5-hour sleep treatment, their resting metabolism while they are sleeping may be higher than the other group’s, and when added to the extended sleep time, this combination may result in more fat loss.

Question 1.42

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No, the media report does not include sufficient detail about the study to support the author’s conclusion. This report does not mention the sample size, the traits (e.g., gender, ethnicity, physical shape) of the participants and shows no evidence to claim that more sleep (over 8.5 hours) would increase the amount of body fat lost. All of these details are important for the reader to assess the validity of the claims and the data being presented.