Scientific Method 2014 Part 1

THE SCIENTIFIC METHOD WHAT IS IT? (DON’T COPY) ○ It is a way to solve problems ○ Do you have any problems to solve? ○ Any big or any small ones? DO ANY OF THESE SOUND FAMILIAR? ○ Where are my shoes? ○ What should I have for lunch? ○ What should I wear today? ○ What is the cure for cancer? ○ Which deodorant lasts longer? WHAT IS THE SCIENTIFIC METHOD? Scientific Method: a general pattern followed by scientists when conducting an experiment. THE STEPS OF THE SCIENTIFIC METHOD Observe" ! You observe a topic that can generate questions for further research. RESEARCH ○ Conduct background research on your topic of interest in order to find out everything you can about your topic and the variables that will come into play ! ○ Only after understanding your topic thoroughly can you decide what question you want to ask and design your experiment QUESTION You ask a question about what is being observed. State the problem or question. WHAT MAKES A GOOD QUESTION? Answerable - with direct observation or with scientific tools. Often start with “What?” Testable – By experiment or measurement Based on what is already known Repeatable EXAMPLES At what temperature does water boil? Does the planet Venus have phases like the moon? NON-SCIENTIFIC QUESTIONS ! ! Based on values or opinions ! ! Often start with “Why?” ! Examples ○ What might the temperature be on a hot day? ○ What might the temperature be on a cold day? ○ Why are In N’ Out burgers better than McDonald’s? ACTIVITY – FORMING A SCIENTIFIC QUESTION Tips on Asking Good Scientific Questions ! 1.Ask several questions about a topic ! 2.Eliminate questions that cannot be answered with DIRECT OBSERVATION or by GATHERING EVIDENCE ! 3.Break broad questions into smaller questions (that can be answered one at a time) ! 4.Write questions so they can be answered by an experiment (“What?” questions are good question!) DIRECTIONS ○ Read the following statements. ○ In the brainwork (left page) section of your notebook, copy the statements ○ discuss with your partner and decide if the topic can be investigated scientifically – write “yes” or “no” ○ For each item you answered “yes”, re-write the topic in the form of a scientific question 1. Some people work better in the morning, and other people work better in the afternoon. ! 2. Taking something that belongs to another person is wrong. ! 3. Snakes travel in pairs. ! 4. Animals behave in strange ways before an earthquake. ! 5. People shouldn’t use things unless they can be recycled. Choose one of the scientific questions you developed and tell what kind of evidence you would need to answer the question. How do you think a researcher could collect that evidence? LET’S RESUME THE NOTES HYPOTHESIS An educated guess on what you think the outcome of the experiment, or the answer to your question will be. HYPOTHESIS (CONT’D) Should be testable Written in the form of an if/then and because statement Can be shown to be true or false by experimenting or observation EXAMPLES Good Bad If plants are given Miracle Plants will grow better when Grow, then they will grow given Miracle Grow. taller because they will have more nutrients. If girls and boys take a math Girls are smarter than boys. test, then the girls will score higher because girls have better study habits. If given a shell choice, then Hermit crabs like colorful hermit crabs will choose shells. colorful shells over drab shells because colorful shells provide more camouflage. ACTIVITY- HYPOTHESIS WRITING PRACTICE DIRECTIONS ○ In the Brainwork section (left page) of your notes, read the following questions and create a hypothesis to go with it. ○ Remember – hypotheses must be written using the If ________ then ___________ because __________ format. ○ Which ball will bounce the highest, a golf ball, a rubber ball, or a ping pong ball? ○ Will adding weight to the wings of a paper airplane make it fly straighter? ○ How does studying with music affect student test scores? ○ How does use of an organized binder the amount of homework a student turns in? ○ How does temperature affect a football players performance? AND NOW – BACK TO THE NOTES EXPERIMENT You will develop and follow a procedure to test your hypothesis. The outcome must be measureable. PARTS OF THE EXPERIMENT Identify variables & constants Identify control & experimental groups Write a procedure Collect data TYPES OF VARIABLES ○ Independent Variable (IV): The one thing you change, limit one per experiment ○ Dependent Variable (DV): what you are measuring, the change that happens due to the IV. ○ Constants: All factors that must stay the same so that any observed changes can be attributed to the IV. GROUPS ○ Experimental Group: the group that is exposed to the IV. ○ Control Group: group exposed to all of the circumstances of the experiment except the IV. This isolates the IV’s effects on the experiment and can help rule out alternate explanations of the results. ● Not all experiments have a control group ADDITIONAL TYPES OF CONTROLS ○ Positive Control: control groups where the conditions guarantee a (+) result. Effective to show the experiment is functioning as planned. ○ Negative Control: control groups where conditions produce a (-) outcome. Helps identify outside influences which may be present that were not unaccounted for, such as contaminants. ACTIVITY – VARIABLE PRACTICE With a little help from the Simpsons EXAMPLE – FIND THE CONTROL & EXPERIMENTAL GROUP AND THE DEPENDANT & INDEPENDENT VARIABLES Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks. EXAMPLE – FIND THE CONTROL & EXPERIMENTAL GROUP AND THE DEPENDANT & INDEPENDENT VARIABLES Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower. Bart Simpson believes that mice exposed to microwaves will become extra strong (maybe he’s been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds (do not do this at home, Bart is a misguided fictional character ☺ ). He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. He found that 8 out of the 10 microwaved mice were able to push the block away. 7 out of 10 non-microwaved mice were able to do the same. ! 1. What was Bart’s hypothesis? 2. Identify the Control group. 3. Identify the independent and dependent variables 4. What might be some of the possible constants? 5. What should Bart’s conclusion be? ANSWERS 1. If mice are exposed to microwaves then they will be extra strong because of the radiowaves. 2. The unexposed mice 3. Independent variable- microwaves Dependent variable- strength 4. Same block of wood, same food, time of day, approx same size mice, etc. 5. Microwave exposure does not significantly change the strength of mice. SUMMARY The scientific method is __________________. The steps of the scientific method are ______________. Good scientific questions should _______________. A hypothesis should be written in the form of _____________. The types of variables in an experiment include ___________, __________, and ___________. The independent variable is __________. The dependent variable is __________. The constants are __________. Additionally there are two groups in an experiment – the __________ group and the _________ group. The difference between them is that _______________..

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