Puzzle Activity. Directions: The Scientific Method involves a series of steps that are used to investigate a natural occurrence.

Transcription

1 Puzzle Activity Work in groups of no more than 3 DO NOT DESTROY MY PUZZLES! TURN IN 1 PAPER PER GROUP! Directions: AS A GROUP: Pull 3 pieces of your puzzle out. Attempt to place your puzzle pieces where you think they should go. DRAW WHAT YOU HAVE!!! Include both piece outlines and shapes on the piece. The involves a series of steps that are used to investigate a natural occurrence. Make a hypothesis about your picture before moving on. How does the puzzle activity relate to the scientific method? Problem/Question Observation/Research Formulate a Hypothesis Experiment Collect and Analyze Results Conclusion Communicate the Results What parts are equivalent to: Problem/Observation: Observation: we have puzzle pieces Question: What does the puzzle form Hypothesis: Hypothesis: I think it s a 1

2 Experiment: (test your hypothesis) put the puzzle together Data: How the pieces fit/more pieces Conclusion: What is it? What happens to theories as scientists get more and better data? There are TWO possibilities. Revise the theory if it s only minor changes needed Toss it and start again if it s major changes The involves a series of steps that are used to investigate a natural occurrence. Problem/Question Observation/Research Formulate a Hypothesis Experiment Collect and Analyze Results Conclusion Communicate the Results 1. Problem/Question: Develop a question or problem that can be solved through experimentation. Why? Maybe you want to test something for yourself, or help refine what to look for. 2. Observation/Research: Make observations and researchyour topic of interest. 2

3 3. Formulate a Hypothesis: Predicta possible answer to the problem or question. Example: Ifsoil temperaturesrise, thenplant growthwill increase, becauseplants grow better in the jungle than in the arctic. 4. Experiment: Develop and follow a repeatable procedure. Include a detailed materials list. The outcome must be measurable (quantifiable). 5. Collect and Analyze Results: Modify the procedure if needed. Confirm the results by retesting. Include tables, graphs, and photographs. 6. Conclusion: Include a statement that accepts or rejects the hypothesis. Make recommendations for further study and possible improvements to the procedure. Scientific For Method scientists, this is usually publication, or a 7. Communicate the Results: Be speech. For you, prepared to presentthe it s usually turning project in the project. to an audience. Expect questions from the audience. Let s put our knowledge of the Scientific Method to a realistic example that includes some of the terms you ll be needing to use and understand. 3

4 Problem/Question John watches his grandmother bake bread. He ask his grandmother what makes the bread rise. She explains that yeast releases a gas as it feeds on sugar. Problem/Question John wonders if the amount of sugar used in the recipe will affect the size of the bread loaf? Observation/Research John researches the areas of baking and fermentation and tries to come up with a way to test his question. He keeps all of his information on this topic in a journal. John talks with his teacher and she gives him a Experimental Design Diagramto help him set up his investigation. Formulate a Hypothesis After talking with his teacher and conducting further research, he comes up with a hypothesis. If more sugar is added, then the bread will rise higher, because yeast feeds on sugar and release gas. 4

5 Hypothesis The hypothesis is prediction about the relationship between the manipulated and responding variables. Must be written in If-then-because format These variables will be defined in the next few slides. Hypothesis Format If (this is done to the manipulated variable), then (this will happen to the responding variable), because (your reasoning based on prior knowledge, observations, etc.) Do you know the difference between the manipulated and responding variables? Manipulated Variable The manipulated, or independent variable, is a factor that s intentionally varied by the experimenter. John is going to use 25g., 50g., 100g., 250g., 500g. of sugar in his experiment. Responding Variable The responding, or dependent variable, is the factor that may changeas a result of changes made in the manipulated variable. In this case, it would be the size of the loaf of bread. Experiment His teacher helps him come up with a procedureand list of needed materials. She discusses with John how to determine the control group. 5

6 Procedure The procedure must be a list of numbered, logical steps. A materials list must be included, and contain everything necessaryfor the experiment. Control Group In a scientific experiment, the control is the group that serves as the standard of (for) comparison. The control group may be a no treatment" or an experimenter selected group. Control Group The control group is exposed to Allexperiments the same with conditionsas a living subject MUST have the a control group. experimental group, except for a control group. the variable being tested. Anything that is testing a deviation from the usual must have Mostexperiments should have a control group. They get the thing we are testing. Experimental Groups The experimental groups are those that receive the changes in the manipulated (independant) variable. John s experimental groups are going to recieve 25g., 100g., 250g., 500g. Identify the manipulated variable, responding variable, experimental and control groups in the following studies. 1. A group of college students were given a short course in speed-reading. The instructor was curious if a monetary incentive would influence performance on a reading test taken at the end of the course. Half the students were offered $5 for obtaining a certain level of performance on the test, the other half were not offered money. 2. A social psychologist thinks that people are more likely to conform to a large crowd than to a single person. To test this hypothesis, the social psychologist had either one person or five persons stand on a busy walking path on campus and look up. The psychologist stood nearby and counted the number of people passing by who also looked up. Manipulated variable: Experimental group: Responding variable: Control group: Manipulated variable: Experimental group: Responding variable: Control group: 6

7 Control Group Because his grandmother always used 50g. of sugar in her recipe, John is going to use that amount in his control group. Constants (Controlled Variables) The constants in an experiment are allthe factors that the experimenter attempts to keep the same. (Everything you aren t testing) Can you think of some constants for this experiment? Constants (Controlled Variables) They might include: Other ingredients to the bread recipe oven used rise time brand of ingredients cooking time type of pan used air temperature and humidity where the bread was rising, oven temperature age of the yeast etc. Experiment John writes out his procedure for his experiment along with a materials list in his journal. He has both of these checked by his teacher where she checks for any safety concerns. Trials Trials refer to replicate groups that are exposed to the same conditions in an experiment. John is going to test each sugar variable 3 times. 7

8 Collect and Analyze Results John comes up with a table he can use to record his data. John gets all his materials together and carries out his experiment. Amt. of Sugar (g.) Trials Average Size (cm 3 ) Control group Size of Baked Bread (LxWxH) cm 3 Size of Bread Loaf (cm 3 ) Collect and Analyze Results John examines his data and notices that his control worked the best in this experiment, but not significantly better than 100g. of sugar. Reliability vs. Validity How can John determine if his results are reliable? Are they valid? Reliability How can John determine if his results are reliable? Are they valid? Reliability The idea behind reliability is that any significant results must be more than a one-off finding and be inherently repeatable. Similar to precision Repeat the experiment, the more trials the better Were all controlled variables accounted for? John repeated his experiment for 3 trials and found an average, he had several controlled variables. Could something else have affected his results? Validity How can John determine if his results are reliable? Are they valid? Validity Validity encompasses the entire experimental concept and establishes whether the results obtained meet all of the requirements of the scientific research method. Similar to accuracy Others can reproduce your results The experiment is designed well and actually tests the hypothesis Are there any sources of bias in the experiment? Were there any other variables that could have affected the results? John created an experiment that fully tested the question that he originally asked and could be repeated by others. Thus we can assume that his experiment is valid with the information that was given. 8

9 Conclusion John rejects his hypothesis, but decides to re-test using sugar amounts between 50g. and 100g. Experiment Once again, John gathers his materials and carries out his experiment. Here are the results. Can you tell which group did the best? Amt. of Sugar (g.) Size of Baked Bread (LxWxH) cm 3 Size of Bread Loaf (cm 3 ) Trials Average Size (cm 3 ) Control group Conclusion John finds that 70g. of sugar produces the largest loaf. His hypothesis is accepted. Writing a Conclusion Recall: Summarize what you did in the experiment Explain: Explain the purpose of the experiment Results: Describe the results of the experiment and what they mean Uncertainties: Describe what you are unsure about or any experimental errors, outliers, or other factors that may have affected the results New:Write at least 2 new things that you learned or new questions raised as a result of your experiment 9

10 Communicate the Results John tells his grandmother about his findings and prepares to present his project in Science class. 10