# The scientific method

Secondary School Science Deparment Coordinator em Colegio Real de Panamá
22 de Mar de 2017
1 de 14

### The scientific method

• 1. 4/27The Perfect Partner for your Digital Business The Scientific Method Pro. Ignacio Anguera Colegio Real de Panamá
• 2. 4/27 The Scientific Method is a process used to find answers to questions about the world around us. The Scientific Method
• 3. 4/27 Use observations you have made to write a question that addresses the problem or topic you want to investigate. Step 2: Formulate a Question Real Case: The Deformed frogs in Minnesota In the summer of 1995, students from Minnesota New Country School unveiled a discovery of deformed frogs in the Minnesota River. By the end of 1996, the MPCA had received numerous reports of deformed frogs from around the state. Step 1: Make Observations Could something in the water in the water be causing the frog deformities?
• 4. 4/27 A possible explanation or answer to the question that can be tested. Based on a prior research. Real Case: The Deformed frogs in Minnesota • The deformities were caused by chemicals in water. Step 3: Form a Hypothesis • The deformities were caused by attacks from parasites. • The deformities were caused by excess of ultraviolet radiation. Statement of a cause and effect (usually stated as an If- then format. Prediction • If a substance in the pond water is causing the deformities, then the water from the ponds that have deformed frogs will be different from the water from ponds in which no abnormal frogs have been found. • If a parasite is causing the deformities, then this parasite will be found more often in frogs that have deformities. • If an increase in UV exposure is causing the deformities, then some frog eggs exposed to ultraviolet light in a laboratory will develop into deformed
• 5. 4/27 Design an experiment that will show whether a particular factor caused an observed outcome. Real Case: The Deformed frogs in Minnesota A control experiment test only ONE factor at a time. Includes: Step 4: Test the Hypothesis Experimental group(s) Control Group All factors between the - control group - and the - experimental groups- are the same except one Because only one variable differs between the -control group -and the -experimental groups-, any difference observed in the outcome is probably caused by the tested variable Independent Variable Dependent Variable Controlled Variable The variable you change on purpose. The response (outcome) to the independent variable. Conditions that remain the same in the experiment.
• 6. 4/27 Design an experiment that will show whether a particular factor caused an observed outcome. Real Case: The Deformed frogs in Minnesota Design an experiment to test the Hypothesis 3: Step 4: Test the Hypothesis Experimental group(s)Control Group Independent Variable Dependent Variable Controlled Variable The variable you change on purpose. The response (outcome) to the independent variable. Conditions that remain the same in the experiment. If an increase in UV exposure is causing the deformities, then some frog eggs exposed to ultraviolet light in a laboratory will develop into deformed frogs. Group 1 Group 2 Group 3 Group 4 No UV light exposure 5 days of UV light exposure 10 days of UV light exposure 20 days of UV light exposure • IV: • DV : • CV Time exposed to UV light Number of deformed frogs Kind of frog, water, temperature
• 7. 4/27 Organize data (tables and graphs) and analyze results. Explains the effect of the variable. Real Case: The Deformed frogs in MinnesotaStep 5: Analyze the Results Experimental group(s)Control Group Group 1 Group 2 Group 3 Group 4 No UV light exposure 5 days of UV light exposure 10 days of UV light exposure 20 days of UV light exposure 0 deformed frogs 2 deformed frogs Organize this information in a data table. 8 deformed frogs 22 deformed frogs The following results are obtained for groups of 100 eggs.
• 8. 4/27 Organize data (tables and graphs) and analyze results. Explains the effect of the variable. Step 5: Analyze the Results How To Do A Graph 1. Draw an x-axis (horizontal) and a y-axis (vertical). The axes represent different variables: • The x-axis represents the independent variable. • The y-axis represents the dependent variable. 2. Choose the scale for each of the axes (evenly spaced intervals that include all of your data) 3. Plot your data on the graph. 4. Label the axes with the appropriate units. 5. Give your graph a title. A good title should explain the relationship between the variables.
• 9. 4/27 Organize data (tables and graphs) and analyze results. Explains the effect of the variable. Real Case: The Deformed frogs in MinnesotaStep 5: Analyze the Results Grou UV light exposure Deformed 1 0 0 2 5 2 3 10 8 4 20 22 20151050 30 0 15 10 5 20 25 UV light exposure (days) Deformed frogs Effect of UV light exposure have over the frogs deformities Data shows that the length of the UV exposure has an effect on the development of frog deformities Conclusions Is the hypothesis supported? What are the implications of the result? What things should be tested to improve the results?
• 10. Summary Scientific Method State a problem Research Hypothesis Test Record & analyze the data Conclusions Prediction in If/then format Variables: • Dependent • Independent • Controlled Control & Experimental group
• 11. Practice!Erika baked a cake for her mother’s birthday. When the cake was taken from the oven, Erika noticed that the cake had not risen. She guessed that the oven had not heated to the correct temperature. She set up the following experiment to test her hypothesis. First, Erika put a thermometer in the oven. She then turned the oven dial to 375 ºF. Erika then read the thermometer she had placed inside the oven. It read 375 ºF. Erika concluded that the oven was heating properly 1. What was Erika’s observations and question? 2. What was Erika’s hypothesis? 3. How she tested her hypothesis? (identify the variables) 4. Which step in the scientific method do you think Erika should do next? 5. List two other hypotheses which might explain why the cake did not rise.
• 12. Practice! A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly. 1.Write a hypothesis. 2. Experimental design (include variables) Clips Distance (cm) 0 346 2 360 4 389 6 390 9 385 12 354 3. The following data was collected. Draw a graph to represent the data. 4. The following data was collected. Draw a line graph to represent the data. 5. What conclusions can you make?
• 13. Practice! A student wanted to test how the consumption of energy drink affect the time a subject can be awake. 1. There is any control group in this data? 2. What should it be? 3. Why would it be important to have? Amount of energy drink (ml) 10 20 40 80 100 Time awake (h) 6.0 8.2 12.5 20.2 26.6
• 14. Practice! A student wanted to know how much fertilizer can make a plant grow bigger. Amount of fertilizer added to soil (g) Average height of plants (cm) 5 13.2 10 14.1 20 15.4 25 16.5 35 16.1 40 15.1