Science: How does it work?

Guiding Question: Can science cure the common cold?Unpack the question

Beyond a body of knowledge, science is a creative process, which involves observingproposing ideas about relationships and causalitytesting the ideasdiscarding ideas that fail the testsrepeating the process to refine ideas and account for new observations Background: What is Science?

Group problem: What is SciencePrior Knowledge Assessment Match up the lettered items on the right to the numbered statements on the left. This is a confirmed or agreed-upon empirical observation or conclusion.

This comprehensively explains many facts and well-supported related hypotheses.

This is missing from the control of an experimental procedure.

This tentatively explains the relationship or cause and effect for an observation or phenomenon.Scientific theoryHypothesisDependent variableControlIndependent variableFactPrediction

Group problem: What is ScienceDiscovery Based on the model below: Observation(s)QuestionHypothesisTestPredictionCollect & Analyze DataReject or Accept HypoModel 1partial model of scientific processWhat leads to hypothesis development?

Prediction is dependent upon what two components of the scientific process?

Group problem: What is ScienceDiscovery & Synthesis Study the two models below: Discover two components in Model 1 that are missing from Model 2.Discover two components in Model 2 that are missing from Model 1.

Draw a single model that includes all the components.Observation(s)QuestionHypothesisTestPredictionCollect & Analyze DataReject or Accept HypoModel 1Model 2

Group problem: What is ScienceApplication Match up the lettered items on the right to the numbered statements on the left. Be prepared to share your groups reasoning for each matching.If vitamin C decreases the risk of catching a cold, then people who take vitamin C supplements should have fewer colds than people who omit the supplement. (C, if then statement)

My aunt takes vitamin C supplements regularly and hasnt had a cold in 10 years. (E, one case, trying to convince, no experiment done)

Vitamin C reduces the risk of catching a cold. (B, statement)

People who eat lots of fruits and vegetables have fewer colds than people who eat few of these foods. (A)

ObservationHypothesisPredictionIntuitionAnecdoteFact

Background: Testing Hypotheses Through ExperimentationObservation 1: road killed animals often have maggotsQuestion: where do they come from?Observation 2: they crawl out of the meat (but we never see them crawl in)Observation 3: flies are always buzzing around road killsHypothesis 1: somehow the maggots come from the fliesHypothesis 2 (an alternative): maggots arise spontaneously in the meatExperimentation is just one way of testing, but its the one most often used to determine cause and effect. Lets take an example.

Background: Testing Hypotheses Through ExperimentationSo, we need to design an experiment to see if either (or both) of these hypotheses can be refuted.

Our goal is to design an experiment that has the POTENTIAL to REFUTE each of our hypotheses. If the experiment refutes one of the hypotheses but not the other, then the one not refuted is supported and is still in the running as an answer to our question.

In science, we disprove or refute hypotheseswe do not prove them right.

Background: Experiments, Predictions, and HypothesesLets consider the second of our two hypotheses: Maggots arise spontaneously in the meat.

To test this hypothesis, we need to think of an experiment we could do and predict its outcome if our hypothesis is correct.

If the outcome of the experiment is NOT what we predicted AND if we can show or argue that our experiment was a good one, then we will have proven wrong or refuted our hypothesis.

Group Problem: Experiments, Predictions, and HypothesesLook at the images below as a clue to help you come up with an experiment that has the potential to test the hypothesis:

Maggots can arise spontaneously from meat.

Remember that you must be able to predict the outcome of your experiment; this is your Prediction. Write that out.

Group Problem: Experiments, Predictions, and HypothesesWhy must we have both open jars and covered ones? Which one of these represents CONTROLS?

Why must we have REPLICATION in this experiment? What do you replicate, the experimental trials or the controls?

Experimentation: One approach to testing hypothesesGroup problem:Discuss remedies youve used to help you get through a cold.

Choose a remedy from your group that you think has been effective and formulate a hypothesis about its effectiveness. (e.g., Consuming Echinacea extract can speed the cure of a cold.)

Outline an experiment that can test your hypothesis. Pay particular attention to how you set up the controls versus the experimentals.

Be prepared to explain to the class how your experiment tests your hypothesis and what you would do to minimize bias.

Group problem: What conclusions can you draw from the graph below? Be prepared to explain your reasoning.(fictitious data)

Chart1

Chart1

Average hours of sleep per night

Percentage of colds in test groups

Figure 1. Correlation of sleep and cold incidence in groups of college students in the United States, 2002-2003.

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455

4.550

4.252

448

451

449

550

544

5.551

5.846

5.343

6.141

6.138

6.336

6.442

6.631

6.839

6.835

728

731

733

752

7.233

7.332

7.328

7.229

7.426

7.528

7.522

7.721

7.828

7.923

7.824

7.722

824

826

820

8.118

8.122

8.125

8.223

8.227

8.222

8.321

8.418

8.517

8.528

8.529

8.618

8.620

8.721

8.719

8.817

8.816

920

9.122

9.518

1033

10.520

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Variability and interpretation of data

Group problem: Based on the results in the table, do you accept or reject the following hypothesis? Be able to explain your choice. Ginseng reduces the risk of catching colds and shortens the duration of their symptoms. Assume adequate control for alternative hypotheses and minimization of bias.

AttributeExperimentalControlCold frequency (average no. during test period)1.72.2Cold duration(average no. days)4.88.1Sample size150150

Science from secondary sourceshttp://media.www.thepawprint.net/media/storage/paper694/news/2007/03/07/Health/Airborne.Flies.Off.Shelves.This.Cold.Season-2760589.shtmlThe Paw Print

Airborne Flies off Shelves this Cold SeasonMatt MeierIssue date: 3/7/07 Section: Health . . . To validate themselves, Airborne conducted a double blind, placebo included study of Airborne's effectiveness in 120 head cold cases. Almost half of them took Airborne for five days and reported the elimination of all cold symptoms compared to those who took an orange-flavored placebo, explained McDowell.

Group problem: Why do we call this a secondary source of information and not a primary one? How reliable is this source?

What scientific claim is reported in this article? What are the strengths and weaknesses of the science behind the claim?

Is there any real science referred to and, if so, what are its strengths and weaknesses?

Is there any indication that this article is biased?

What would you do next if you wanted to further authenticate any claims in this article?

The Paw Print Airborne Flies off Shelves this Cold SeasonMatt MeierIssue date: 3/7/07 Section: Health

***At end: Now were are going to explore an example of how a hypothesis might be formulated and tested.

*At end: Now were are going to explore an example of how a hypothesis might be formulated and tested.

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