What is Science?

Decide whether the following statements are true or false.

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.

What is Science?or

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.

8. A hypothesis becomes a theory which becomes a law.

9. A hypothesis is an educated guess.

10. A general and universal scientific method exists.

1. 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.

• Science actually attempts to disprove ideas (hypotheses).

• Science is limited strictly to solving problems about the physical and natural world.

• Explanations based on supernatural forces, values or ethics can never be disproved and thus do not fall under the realm of science.

2. Science can prove anything, solve any problem or answer any question.

3. Any study done carefully and based on observation is scientific.

• Science must follow certain rules.

• 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

4. Science can be done poorly.

• Science can be done poorly, just like any other human endeavor.

• Quality control mechanisms in science increase the reliability of its product.

5. Anything done scientifically can be relied upon to be accurate and reliable.

6. Different scientists may get different solutions to the same problem.

• Results can be influenced by the race, gender, nationality, religion, politics or economic interests of the scientist.

• Sampling or measurement bias can result in different solutions to the same problem.

People need to be able to evaluate scientific information in order to make informed decisions about:

• Health care• Environmental issues• Technological advances• Public health issues

7. Knowledge of what science is, what it can and cannot do, and how it works, is important for all people.

8. A hypothesis becomes a theory which becomes a law.

• Major misconception• There is not a natural progression

from hypothesis to theory to law• This myth deals with the general

belief that with increased evidence there is a developmental sequence through which scientific ideas pass on their way to final acceptance

Quote of the Day:

• Theories are nets to catch what we call “the world:” to rationalize, to explain, and to master it. We endeavor to make that mesh finer and finer.”

– Karl Popper (1935)

9. A hypothesis is an educated guess.

• A hypothesis is a testable statement based upon research

• Most of the time in science class, students are asked to propose a hypothesis during a laboratory experience, but they are actually giving a prediction.

• As for those hypotheses that are really forecasts, perhaps they should simply be called what they are, predictions.

10. A general and universal scientific method exists.

• Scientists approach and solve problems with imagination, creativity, prior knowledge and perseverance.

• These are the same methods used by all problem-solvers.

• The lesson to be learned is that science is no different from other human endeavors when puzzles are investigated.

So, What is Science?• Modern science is a process by which we try

to understand how the natural world works and how it came to be that way.

• It is NOT a process for merely collecting "facts" about, or just describing, the natural world, although such observations do provide the raw material for scientific understanding.

• There is no certainty in science, only degrees of probability (likelihood), and potential for change.

What is Science NOT?

• Science ≠Proof• Science ≠ Certainty• Science ≠ Belief

What is Science?• Scientific understanding can always be

challenged, and even changed, with new ways of observing, and with different interpretations.

• The same is true of scientific facts. • New tools, techniques, and advances in

technology have resulted in new observations, sometimes forcing revision of what had been taken as fact in the past.

Why is science so useful?

• The limitations are the strengths of science.

• Scientific knowledge is the most reliable knowledge we have about the natural world.

• Science has enabled much of our work in space exploration, modern medicine, agriculture, and technology

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?

Two main types of bias:

1. Sampling bias

2. Measurement Bias

Bias = A prejudiced presentation of material

Sampling Bias

Sample = A group of units selected to be “measured” 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.

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:

Measurement Bias

Is the method of data collection chosen in such a way that data collected will best match reality?

Evaluate the technique:

• Measurements taken accurately

• No additions to the environment that will influence results

• Experiment designed to isolate the effect of multiple factors

Good science depends on a well-designed experiment that minimizes bias by using the

appropriate:

•Sample size•Sample selection •Measurement techniques

***for the question being investigated

Summary

•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.

Identifying good science: Look for signs of bias!

• Language

• Appropriate data reported to back conclusions

• Data source

Language

“Scientifically-proven” * 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!

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?

Data Sources

All organizations produce unbiased data. However, it is important to understand the organization’s 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

The Effects of Teen SmokingExamining 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%)

SignificanceΧ2=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.

You are now scientists

• Learn to question• Do not prejudge• Have an open mind to topics• Realize there is more that you do not know,

than what you do know