Scientific Method Problem/Purpose Hypothesis Experiment Controls Variables Constants Materials Procedure Data and Observations Analysis Conclusion Theory
Problem/Purpose Identify what it is you want to investigate, usually based on something you ve observed Do plants need food to grow?
Hypothesis What you think will happen It is a testable explanation for an observation Sometimes given in the If then.. format If a plant is given more food, it will grow taller then if it is given no food at all
Experiment The controlled test of a hypothesis Contains: Constants Control group Variables
Experiment You want to test the effects of different amounts of fertilizer (food supplement) on plant growth. You create an experiment using 4 plant setups. All plants are the same and are planted in 3 cups of the same potting soil. They are given 1 cup of water daily and are given 8 hours of sun every day. Group 1 is given 1 cup of plant fertilizer Group 2 is given ½ cup of plant fertilizer Group 3 is given 2 cups of plant fertilizer Group 4 is given no fertilizer at all. Their length is measured every 5 days.
Set-up of controlled experiment: Experiment Group 1 Group 2 Group 3 Group 4
Your results after 15 days: Experiment Group 1 Group 2 Group 3 Group 4
Experiment Constants- things that are the same for all groups What were your constants in the experiment? Amount of soil, water, light Type of plant, soil Time increments for measuring growth
Experiment Control group Serves as a standard of comparison Contains all the constants, but not the variable What was the control group in the experiment? Group 4: received no fertilizer
Experiment Variables Independent variable What you (the scientist) are changing in the experiment Causes the dependent variable to change Goes on X (horizontal) axis of graph What was the independent variable in the experiment? Amount of fertilizer
Experiment Variables Dependent variable what you are testing for/measuring Is changed by the independent variable goes on Y (vertical) axis of graph What was the dependent variable in the experiment? Rate of plant growth
Materials What you used to conduct the experiment What were the materials used in your experiment? 4 pots 12 cups of soil 4 plants 3 ½ cups fertilizer 60 cups water Light source
Procedure Procedure- a logical procedure in solving the problem that is listed in numerical step format. Write out the procedure, listing steps in numerical order 1. Fill each pot with 3 cups soil 2.
Data and Observation Recording what happened during the experiment Includes the results in the form of data Data should be included as charts, tables and graphs Make sure all data tables have a title and are labeled
Data and Observation Group # Plant height after 15 days Amount of fertilizer (cups) Plant height (cm) 1 1 10 2 1/2 6 3 2 15 4 0 5
Analysis Graphing guidelines Include a title indicating variables (what exactly does this chart show the reader) Label the Y and X axis DRY- Dependent/Responding variable on Y-axis MIX- Manipulated/Independent variable X-axis
Analysis Graphing guidelines the entire area of the graphing space should be used (determine appropriate increments) Indicate units of measure
Plant growth based on the amount of fertilizer given over a 15 day time period Plant growth in centimeters 14 12 10 8 6 4 2 O Group 1 Group 2 Group 3 Group 4 The amount of plant fertilizer
Conclusion Addresses the hypothesis Shows that the data supported or disproved your hypothesis Make a clear relationship between the problem and results Demonstrate a connection between the experiment and the larger context of form as it relates to function Make predictions on other tests that may also be effective
Theory Theory- Explanation for observations proven through repeated and varying experimentation Unifying explanation for a broad range of observations
Identify the: Control Group 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. Independent Variable Dependent Variable What should Smithers' conclusion be? How could this experiment be improved?
What was the initial observation? 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 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. Identify the- Control Group Independent Variable Dependent Variable What should Homer's conclusion be?
Identify the- Control Group Bart 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. 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 10 of the microwaved mice were able to push the block away. 7 out of 10 of the non-microwaved mice were able to do the same. Independent Variable Dependent Variable What should Bart's conclusion be? How could Bart's experiment be improved?
Identify the- Control Group Krusty was told that a certain itching powder was the newest best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the Experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes. Independent Variable Dependent Variable Explain whether the data supports the advertisements claims about its product.
Lisa is working on a science project. Her task is to answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair growth". Her family is willing to volunteer for the experiment. Describe how Lisa would perform this experiment. Identify the control group, and the independent and dependent variables in your description.