Presentation on theme: "What does science mean to you??? This power point and the copyrighted images within it may not be reproduced or distributed except for normal classroom."— Presentation transcript:
What does science mean to you??? This power point and the copyrighted images within it may not be reproduced or distributed except for normal classroom use.
Science is a way of knowing about the natural world, using a process, designed to reduce the chance of being misled.
Everyone does science (or should) You don’t have to have a PhD to do science, you just follow some basic steps and rules.
An example of the 8 Steps in the Process of Science You come home one night, flip on the light switch, and nothing happens.
2. QUESTION Why didn’t the light turn on? Keep the question open-ended. For example, don’t ask “Did the light not turn on because the bulb is burned out?”
3. LITERATURE REVIEW Find out what lights require to function and what can cause them not to function. Lights need electricity to work
4. MULTIPLE HYPOTHESES What are all the possible answers (hypotheses) to the question? H1: Power is out to the house H2: The light bulb is burned out H3: The lamp is broken You need to think of many hypotheses to avoid jumping to a conclusion
5. DEDUCTIONS If the light did not turn on because the power is out to the house… Example Deduction for H1: then …I would expect no other electric appliances to work in the house. For each hypothesis, determine what evidence (data) would be required to refute or support the hypothesis? In other words, what would we expect to observe if we conducted a test. H1: Power is out to the house
5. DEDUCTIONS D2) If the light did not turn on because the light bulb is burned out… Example Deduction for H2: Then… a new bulb will work the bulb will rattle when shaken Then… H2: The light bulb is burned out
5. DEDUCTIONS D3) If the light did not turn on because the lamp is broken Example Deduction for H3: then…a new light bulb will not work. H3: The lamp is broken
6. TESTS/ EXPERIMENTS Conduct tests to collect actual data Examples: 1)Turn on other appliances 2)Shake the light bulb record sound 3) Try bulb in a functioning lamp
7. TENTATIVE CONCLUSIONS Which hypotheses were supported and refuted by the actual data? H1 refuted: Other appliances worked H2 supported: Bulb rattled when shaken H3 refuted: New bulb did work Tentative Conclusion: Light bulb was burned out Test H2 again by putting “burned out” light bulb in a functioning lamp!
8. PEER REVIEW Submit your report to a scientific journal. Scientists whose reputation is at stake, and chosen by the journal editor, will determine whether your report is scientifically sound and should be published.
Science Rules of Thumb 1. Maximize Sample Size: The larger the sample size the more accurate the estimate. [Have sample sizes in the thousands or more if possible] 2. Representative Sample: The sample must represent the variation in the whole population. E.g., Use random or systematic sampling to avoid biasing the data. E.g., you don’t want your sample to include only men if you are studying the effect of a medicine on people.
Science Rules of Thumb 3. Use Controlled Experiments for Causal Questions Use to answer questions concerning what caused something to happen. Two groups (control & experimental) are treated identically except for the one factor being tested. If the results are different between the experimental and control groups, then one knows that the change was caused by the single factor that differed between the two groups.
Science is NOT just facts Science does NOT answer right and wrong questions Science does NOT prove
Some Definitions Hypothesis = a possible explanation for an observed phenomenon = a possible answer to a question – Must be able to generate testable deductions Theory = conceptual framework that explains a variety of observations, is supported by experimental evidence and is capable of predicting new phenomena = as sure as science ever gets –Not “just a guess,” as used in everyday language
Examples of theories? – Theory of relativity – Theory of evolution by natural selection – Theory of plate tectonics
MEALWORM MYSTERY This is just for fun to test your understanding of controlled experiments A student conducted 3 experiments to determine how mealworms respond to light and moisture. All variables except light and moisture were held constant from experiment to experiment. For each experiment, 12 mealworms were placed in the center of a box and then their positions were recorded 24 hours later.
EXPERIMENT 1 QUESTION: Are mealworms attracted to light? mealworm QUESTION 2: Are mealworms affected by moisture? Answer?You can’t tell; it could be either or both
EXPERIMENT 2 QUESTION: Are mealworms affected by light? QUESTION 2: Are mealworms affected by moisture? Answers?They are affected by light; we don’t know about moisture
EXPERIMENT 3 QUESTION: Are mealworms affected by light? QUESTION 2: Are mealworms affected by moisture? Answers?With just this experiment, it seems they didn’t move
EXPERIMENT 3 QUESTION: Are mealworms affected by light? QUESTION 2: Are mealworms affected by moisture? Using the information from the other 2 experiments… Answers?Yes and Yes (despite attraction to light, they avoided wet
THE EXPERIMENTS 1 2 3 QUESTION: Which variables affect mealworm movement based on the above experiments (note that movement may be either toward or away from something)? A. Light but not moisture. B. Moisture but not light. C. Both light and moisture. D. Neither light nor moisture. E. Can’t tell. mealworm Without the controlled experiment we would know nothing!