PLANNING A SCIENCE FAIR PROJECT

Transcription

1 PLANNING A SCIENCE FAIR PROJECT Dr. Becky Gonda Outreach Coordinator Department of Biological Sciences University of Pittsburgh

2 WHAT WE LL COVER A Brief Experiment Selecting a Topic Planning Your Experiments Interpreting an Experiment 2

3 Why is yeast used in cooking? Single-cell Eukaryotes

4 Do yeast cells use sugar like our cells? Glucose Carbon Dioxide + Ethanol + Energy 4

5 Is sugar required for yeast respiration? 5

6 SELECTING A SCIENCE FAIR TOPIC What is Science? 6

7 Science is a body of knowledge about our natural world and how it works, CONTENT KNOWLEDGE a process of exploration and discovery, INQUIRY PROCESS the quest for solutions to human needs. SOCIAL CONTEXT 7

8 The Triad of Science A good Science Fair project will blend all three of these aspects of science! Inquiry Process How? Content Knowledge What? Social Context Why? 8

9 Pick a Science Fair Topic That is interesting to YOU. investigates something useful or relevant to YOU and others. YOU can investigate with available materials and know-how. Inquiry Process How? Content Knowledge What? Social Context Why? 9

10 Some Example Science Fair Topics 10

11 Habits of Scientific Thinking Skepticism Withhold decisions Open-Mindedness Consider all alternatives Rationalism Seek objective, empirical evidence Differentiate between fact and opinion 11

12 CONDUCTING RESEARCH: THE SCIENTIFIC METHOD Problem Hypotheses Experiments Predictions Results Conclusions

13 Scientific Method State the problem or question. List all hypothetical causes/solutions of the problem or answers to the question. Design an experiment to test one hypothesis. Predict results of the experiment. Conduct experiment and record observed results. Draw conclusions from the results. Source: Robert M. Pirsig, Zen and the Art of Motorcycle Maintenance. New York: Bantam; (Chapter 9) 13

14 Scientific Method Step 1: State the Problem Your project can focus on a question you wish to answer, Question: How does temperature affect enzyme activity? or a problem you wish to solve, Problem: How do I melt ice on my driveway in the most economical way? or a goal you wish to accomplish. Goal: To build a robot that scoops out the cat s litter box. 14

15 Scientific Method Step 2: Make Hypotheses Review what is already known about the subject. Each hypothesis is one possible explanation or prediction, based on pre-existing knowledge, that is testable. Think of as many plausible explanations as you can. Start by testing one! 15

16 Problem: Is sugar required for yeast to produce carbon dioxide gas? What is your hypothesis for this experiment? 16

17 Scientific Method Step 3: Design Experiments Design a controlled experiment to test the hypothesis. Designed to measure a single variable condition. Any pair of samples differs in only one way. Other environmental conditions are controlled. Everything else about any pair of samples is the same. See section on Experimental Variables. 17

18 Our Quick Experiment Yeast + Glucose Carbon Dioxide + Ethanol + Energy Is sugar required for gas production? Yeast + Sugar Yeast alone Sugar alone 20 ml warm water 1/2 tsp yeast 1/4 tsp sugar 20 ml warm water 1/2 tsp yeast 20 ml warm water 1/4 tsp sugar Mix ingredients together, and measure how much foam is produced in 1 minute 18

19 Scientific Method Step 4: Make Predictions Making predictions are important for conducting your experiments and analyzing the results Helps you have a sound project Format of a Prediction statement If (this idea is true)... And I (do this action)... Then (this result will occur). 19

20 Scientific Method Step 5: Obtain and Analyze Results Collect data through observation and measurement. Choose quantitative over qualitative measurements. Department of Biological Sciences Quantitative data can be analyzed graphically and statistically. Is variability associated with manipulated variable greater than variability due to chance or other variables? 20

21 Our Model Experiment Mix ingredients together and measure the amount of foam (CO 2 ) Is sugar required for gas production? 21

22 Our Model Experiment Yeast + Sugar Yeast alone Sugar alone 4ml 0ml 0ml 22

23 The Effect of Temperature on Enzyme Activity Volume of Bubbles (ml) Yeast + Sugar Yeast alone Sugar alone How can we be sure these results are accurate? 23

24 The effect of sugar on yeast carbon dioxide production: Trial 1 The effect of sugar on yeast carbon dioxide production: Trial 2 Volume of Bubbles (ml) Yeast + Sugar Yeast alone Sugar alone Volume of Bubbles (ml) Yeast + Sugar Yeast alone Sugar alone The effect of sugar on yeast carbon dioxide production: Trial 3 7 Repeat your experiments. Volume of Bubbles (ml) Yeast + Sugar Yeast alone Sugar alone 24

25 Scientific Method Step 6: Draw Conclusions Formulate conclusions based on the interpreted data. Department of Biological Sciences Identify if your hypothesis is consistent with the observed results. Conclusions are only as good as the data is accurate. Revise hypothesis, redesign experiment, and conduct further studies as necessary. 25

26 Do the results support the hypothesis? 8 The effect of sugar on yeast carbon dioxide production 7 6 Volume of Bubbles (ml) Yeast + Sugar Yeast alone Sugar alone 26

27 DESIGNING AN EXPERIMENT: EXPERIMENTAL VARIABLES Manipulated Variables Controlled Variables Responding Variables Uncontrolled Variables

28 Manipulated Variable Controlled Variable Responding Variable Uncontrolled Variable Independent variable -treatment that is changed or manipulated; Each sample is subjected to different conditions for the manipulated variable: treatment, amount, time, duration, etc.; cause Identical in all conditions; ruled out as affecting outcome Dependent variable -properties that are observed or measured; effect Factors which may impact experimental samples or subjects differently, resulting in effects that are not due to the manipulated variable. Ex. Experimental error, bias, environmental conditions 28