1. What is Science?
or
1. Science is concerned with understanding how nature and the
physical world work.
2. Science can prove anything, solve any problem, or answer any
question.
3. Any study done carefully and based on observation is
scientific.
4. Science can be done poorly.
5. Anything done scientifically can be relied upon to be accurate
and reliable.
6. Different scientists may get different solutions to the same
problem.
7. Knowledge of what science is, what it can and cannot do, and
how it works, is important for all people.
2. Science is concerned with understanding how
nature and the physical world work.
Science is a process by which we try to understand how
the natural and physical world works and how it came to be
that way.
3. ā¢ Science actually attempts to disprove ideas
(hypotheses).
ā¢ Science is limited strictly to solving problems about
the physical and natural world.
ā¢ Explanations based on supernatural forces, values
or ethics can never be disproved and thus do not fall
under the realm of science.
Science can prove anything, solve any
problem or answer any question.
4. Any study done carefully and
based on observation is scientific.
ā¢ Science must follow certain rules.
ā¢ The rules of science make the scientific process as
objective as is possible.
Objective = Not influenced by feelings, interests
and prejudices; UNBIASED
vs.
Subjective = Influenced by feelings, interests and
prejudices; BIASED
5. Science can be done poorly.
ā¢ Science can be done poorly, just like any other
human endeavor.
ā¢ Quality control mechanisms in science increase the
reliability of its product.
Anything done scientifically can be relied upon
to be accurate and reliable.
6. Different scientists may get different solutions
to the same problem.
ā¢ Results can be influenced by the race, gender,
nationality, religion, politics or economic interests of the
scientist.
ā¢ Sampling or measurement bias can result in different
solutions to the same problem.
7. People need to be able to evaluate scientific information in
order to make informed decisions about:
ā¢ Health care
ā¢ Environmental issues
ā¢ Technological advances
ā¢ Public health issues
Knowledge of what science is, what it can and
cannot do, and how it works, is important for
all people.
8. Objectivity is the key to good science.
To be objective, experiments need to be designed
and conducted in a way that does not introduce
bias into the study.
What is good science?
9. ā¢ A prejudiced presentation of material
ā¢ A consistent error in estimating a value
Two main types of bias:
1. Sampling bias
2. Measurement Bias
Bias =
10. Sampling Bias
Sample = A group of units selected to be
āmeasuredā from a larger group (the
population).
Sampling bias is introduced when the
sample used is not representative of the
population or inappropriate for the question
asked.
11. 1. Use a RANDOM SAMPLE = every individual
has an equal likelihood of being chosen.
2. Limit the question asked to the specific group
sampled.
SAMPLE SIZE: Is the sample big enough to get a good
average value?
SELECTION OF SAMPLE: Does the composition of the
sample reflect the composition of the population?
Factors that contribute to sampling bias
Factors such as location, age, gender, ethnicity, nationality
and living environment can affect the data gathered.
How to minimize sample selection bias:
12. Measurement Bias
Is the method of data collection chosen in such a
way that data collected will best match reality?
Evaluate the technique:
ā¢ Measurements taken accurately
ā¢ No additions to the environment that
will influence results
ā¢ Experiment designed to isolate the
effect of multiple factors
13. Good science depends on a well-designed
experiment that minimizes bias by using the
appropriate:
ā¢Sample size
ā¢Sample selection
ā¢Measurement techniques
***for the question being investigated
Summary
14. Independent duplication = Two or more scientists from
different institutions investigate the same question
separately and get similar results.
Peer-reviewed journal = A journal that publishes articles
only after they have been checked for quality by several
expert, objective scientists from different institutions.
The scientific community engages in
certain quality control measures to
eliminate bias.
Results are verified by independent duplication
and publication in a peer-reviewed journal.
16. Identifying good science: Look for signs
of bias!
ā¢ Language
ā¢ Appropriate data reported to
back conclusions
ā¢ Data source
17. Language
āScientifically-provenā
* Science does not seek to prove but to disprove
* Be suspicious of this claim!
Emotional appeals
* Conclusions should be data-based
* Emotional appeals usually are not data-based
Strong language
* Scientific conclusions should only report what the
data supports.
* Words should be chosen very carefully to avoid
exaggeration or claims not supported by data.
THE DATA SHOULD CONVINCE YOU,
NOT THE WORDS USED!
18. Appropriate data reported to back
conclusions
Are samples and measurements appropriate
for the conclusion presented?
Are multiple factors properly accounted for
to justify the interpretation of the data?
19. Data Sources
All organizations produce unbiased data. However,
it is important to understand the organizationās
motivation to be able to identify potential bias. In
some situations, the need to promote special
interests or make profits may lead to bias.
1. University Research
2. Corporate Research
3. Government Research
4. Research by Special
Interest Groups
21. Examining the Data Source
Investigations of Passive Smoking Harm:
Relationship between Article Conclusions & Author
Affiliations
Number (%) of Reviews
Article Conclusion Tobacco Affiliated
Authors (n=31)
Non-Tobacco Affiliated
Authors (n=75)
Passive smoking harmful 2 (6%) 65 (87%)
Passive smoking not harmful 29 (94%) 10 (13%)
Significance Ī§2
=60.69; P<.001
Barnes, Deborah E. 1998. Why review articles on the health effects of
passive smoking reach different conclusions. JAMA. 279(19): 1566-1570.
22. Ana MarĆa RodrĆguez
ā¢ Graduated from SimĆ³n Bolivar
University in Caracas, Venezuela;
bachelors degree in biology.
ā¢ Received a PhD in Biology and
Immunology from the Venezuelan
Institute of Scientific Research.
ā¢ Research Associate at Southwestern
Medical Center in Dallas and at the
University of Texas Medical Branch in
Galveston.
ā¢ Assistant Professor of Biology at
University of Tulsa in Oklahoma.
ā¢ Currently, a full-time children science
writer and writes for YES MAG,
Highlights for Children, and Current
Health 1. Sometimes writes under the
pen name, Mariana RelĆ³s.
Hinweis der Redaktion
ļ§ This slide contains the 8 true/false questions that compose the Opening Questions section in the student workbook. It can be displayed while students work on answering the questions.
Science is primarily concerned with understanding how the physical world works.
True.
Science is a process by which we try to understand how the physical world works and how it came to be that way. The physical world includes the world we can observe with our senses with or without technological aids.
Science can prove anything.
FALSE.
The process of science, when properly applied, actually attempts to disprove ideas (hypotheses) by testing or challenging the hypothesis with observations (data) gathered from carefully designed experiments. If the idea survives testing, then it is stronger, and more likely an accurate explanation. Science is a process which can only produce āpossibleā or āhighly probableā explanations for natural phenomena; these are never certainties. With new information, tools, or approaches, earlier findings can be replaced by new findings.
Ā
Science can solve any problem or answer any question.
FALSE.
The realm of science is limited strictly to solving problems about the physical world, a world that we can observe with our senses. Science is not properly equipped to handle the supernatural realm, nor the realm of values and ethics, realms that cannot be observed with our senses. Scientific explanations must be potentially disprovable. Explanations based on supernatural forces, values or ethics can never be disproved and thus do not fall under the realm of science.
Any study done carefully and based on observation is scientific.
FALSE.
Science must follow certain rules; otherwise, it&apos;s not science (just as soccer is not soccer if its rules are not followed). The rules of science are intended to make the process as objective as is humanly possible, and thereby produce a degree of understanding that is as close to reality as possible. Scientific explanations must be based on careful observations and the testing of hypotheses.
Ā
ļ§ Define objective
Science can be done poorly.
TRUE.
Anything done scientifically can be relied upon to be accurate and reliable.
FALSE.
Science can be done poorly, just like any other human endeavor. We are all fallible, some of us make fewer mistakes than others, some observe better than others, but we are still subjective in the end. Self-correction mechanisms in science increase the reliability of its product.
Different scientists may get different solutions to the same problem.
Science can be influenced by the race, gender, nationality, religion, politics or economic interests of the scientist.
TRUE.
Intentional or unintentional sources of bias introduced in a study can result in different solutions to the same problem. Scientists are people, and although they follow certain rules and try to be as objective as possible, both in their observations and their interpretations, their biases are still there. Unconscious racial bias, gender bias, social status, source of funding, or political leanings can and do influence one&apos;s perceptions and interpretations.
Unfortunately, science is all too frequently misused. Because it works so well, there are those who apply the name of science to their efforts to &quot;prove&quot; their favorite cause, even if the rules of science were not followed. Such causes are properly labeled &quot;pseudosciences&quot;. Also, some scientists have been known to do fraudulent work, in order to support their pet ideas. Such work is usually exposed sooner or later, due to the peer review system and the work of other scientists.
Knowledge of what science is, what it can and cannot do, and how it works, is important for all people.
People need to be able to evaluate scientific information and make decisions about the information. Scientific information is used to support political arguments, advertise products, and inform people of factors that affect their health. It is important for all people to be scientifically literate in order for them to be able think critically about what to vote for, what to buy and how to protect their health.
Given that science can be poorly done, what is good science?
Discuss these examples to help explain the way these different factors can cause sampling bias.
Ā
Sample Size:
Ex. To determine the average height of students in this classroom, how many students should I measure to get the best estimate? If I only measure 3 will my mean be accurate?
Ā
Sample Selection:
Factors such as location, age, gender, ethnicity, nationality and living environment can affect the data gathered for a sample. A good experiment controls for these factors by using a random sample or by limiting the question asked to the specific group represented by the sample.
Ā
Random sample = Samples drawn in such a way that every individual has an equal likelihood of being selected.
Ā
Example of random sample: Rolling dice, flipping a coin
Ā
Example of sample selection bias:
I want to find the average height of students in the classroom. I notice a list of students that are to be excused early because they are on the basketball team and have a game. I decide to use this list to pick the students that will be in my sample. How might this method of selecting my sample bias my estimate of average height?
Ā
ļ§ What are factors that contribute to sampling bias?
Ā
ļ§ What are some ways to minimize sampling bias?
Discuss these examples to help explain the way measurement technique can cause measurement bias.
Ā
Use measurement tool correctly
Ex. When measuring height, I must be careful to start the measuring tape at exactly at 0, not at 1 cm.
Ā
No additions to the environment that will influence results
Ex. I take height measurements of everyone in the classroom and let them keep their shoes on. All shoes add height, some more than others, and this will change the measure I get for average height.
Ā
Experiment designed to separate out the affect of multiple factors
Ex. I propose the hypothesis that students that sleep more than 7 hours the night before a test will perform better on the test. I ask students to report how much sleep they received the night before on their tests and compare this with their test scores. I do not ask or control for other factors such as how much each student studied or whether they ate breakfast. How can I know that any trend I observe is reflective of how much sleep they received and not other factors?
Ā
ļ§ What are 3 factors that contribute to measurement bias?
The scientific community has long recognized that bias can be found in scientific studies either by unintentional mistakes on the part of scientist or by intentional attempts to make data show a particular, desired result. There are several ārulesā or procedures used by the scientific community to eliminate (or at least reduce) bias in science. These procedures include independent duplication and confirmation by others and the requirement for publication in a peer-reviewed journal.
Ā
ļ§ What measures does the scientific community take to minimize bias in science?
The problem is most of this debate and procedures take place in scientific journals which are rarely read by the public with good reason. I do not speak Japanese. If I picked up a book written in Arabic I would only be able to admire the beautiful characters; I wouldnāt understand a thing unless I received training in the Arabic language. Scientific articles are full of scientific references and language that usually require advanced training in the scientific field in order to be understood. This has nothing to do with intelligence!
Ā
So, how can those of us who have not (yet) received advanced scientific training identify good science?
ļ§ What are some clues that scientific information you are reading is biased?
Discuss examples for evidence of bias.
Ā
1. Emotional appeal ā gives emotional reasons for believing or not believing the scientific
conclusions. āPeople will senselessly die unless we use Vacinax now!ā
Ā
2.āscientifically-provenā ā science sets out to disprove, not prove things. Thus anytime
you encounter the phrase āscientifically-provenā, be suspicious.
Ā
3. Identify strong language ā ācleanestā, ācheapestā, ā most efficientā, āin the worldā
For each point you can use the examples used previously:
Ā
Are sample and measurements appropriate for the conclusion presented?
Ex. Determining average height in classroom using basketball team or taking measurements with shoes on.
Ā
Are multiple factors properly accounted for to justify the interpretation of the data?
Ex. Correlation between sleep and test results.
You may want to highlight that there are plenty of examples of both good and bad research done by all of these groups. A careful understanding of the interests and funding sources of research will give you an idea of what the bias might be if the research is biased. However, even if a scientist has an interest in getting certain results it does not mean that their research will be biased. If they are a good scientist, they will be true to the scientific process and they will design good experiments and report data honestly, regardless of their interests.
Exploration of the concepts presented in this lecture are the focus of the classroom activity on teenage smoking.
Ā
At this point, handout the activity, Smoking Bias. You can keep this slide up while you complete the activity and return to the last two slides at the conclusion of the activity to wrap up and assign homework.
After you have reviewed the 6 experiments in the Smoking Bias activity as a class, share these finding with the class. This is real research and clearly shows that bias unfortunately can and does affect scientific research.
This slide can be used to introduce the homework assignment, āIdentifying Bias- Bald Eagles and DDT. Dr. Mariana Relos is an example of a person who must evaluate different sources of information for bias and accuracy every day as part of her job. She writes childrenās articles for science magazines. The homework assignment begins with an interview of Dr. Relos. Students are placed in the role of a reporter while they review concepts about bias in science, practice identifying bias, develop critical thinking skills and learn about history of DDT use in the United States.