The Scientific Method and Forensic Science Objective: To learn how to apply the steps of the scientific method in order to solve a case.

Saving Sam Brain storm ideas with your lab group before you begin your mission. Write down your ideas in your NB.

Saving Sam Analysis 1. Create an experimental question based on the activity we did in class. 2. Label the procedure in your NB 3. How did you organize your data? Why?

Steps of the Scientific Method Observation or question Formulate a hypothesis Create an experiment Conduct Experiment to collect data Analyze data and formulate conclusion

Hypothesis Attempts to _________ something. Must: 1. Include a ________ and _________ 2. Be able to be _______ 3. Be written as a ______________ explain cause tested statement effect

Which of the following would be considered a hypothesis? 1. Hyperactivity is unrelated to eating sugar. 2. If you get 6 hours of sleep, you will do better on tests. 3. Apples taste better than oranges.

The Walking Moai of Easter Island Create a hypothesis that explains how these giant statues “walked” Before you create a hypothesis, what background information do you need?

The “Walking” Moai of Easter Island Most of the statues weighed five tons Most statues have wider bases than shoulders Wood was used to move the Moai According to legend the Moai “walked”

The Answer

Creating An Experiment Should only test _____________ variable Should include an __________ group and a _________ group One independent control experimental

Continued Control group Is used to _________ against experimental groups. _________ get the treatment/variable Experimental group ____________ the treatment/variable compare Does not Receives

Variables Independent variable: Variable that __________ The _________ E.x. Dependent variable: Variable that is ________ by the change The __________ E.x. effected changes effect cause

The Orchid I notice that my orchid plant is starting to die. I think that it may be getting too much sun. I leave the plant in its normal spot for two weeks and notice that 2 flowers have died. I move it a shady area of the room for two weeks and notice that none of the flowers died. Then I move it to a sunny window sill and notice that all of the flowers have died. a) Identify the control variable b) Identify the independent variable c) Identify the dependent variable

Scooby Observation: I always wash Scooby with Petsmart brand shampoo and notice he is losing his hair. Hypothesis: Petsmart brand shampoo is causing Scooby to lose his hair. Experiment: Wash Scooby with Pestsmart shampoo for two weeks. Switch to Purina dog shampoo for two weeks. Results: Scooby lost equal amounts of hair during the experiment. Identify the following: a) Independent variable: b) Dependent Variable: c) The Control:

Effect of Soap on Surface Tension Analysis 1. Identify the control group 2. Identify the independent variable 3. Identify the dependent variable 4. Did we set up our experiment correctly? Explain your answer. 5. Cite sources of experimental error.

The Orchid I notice that my orchid plant is starting to die. I think that I may be over watering my plant. a) Create a hypothesis b) Set up an experiment to test your hypothesis. You must include an experimental group and a control group. c) Identify the independent variable and the dependent variable.

Data Analysis Look for a SIGNIFICANT __________ in the experimental group(s) Compare the ________ group to the experimental group(s) control difference **The experimental group = the independent variable

What is a significant Difference? Significance is a statistical term that tells how sure you are that a difference or relationship exists relating to observations that are unlikely to occur by chance and that therefore indicate a systematic cause. A Significant Difference between two groups or two points in time means that there is a measurable difference between the groups and that, statistically, the probability of obtaining that difference by chance is very small (usually less than 5%)

Formulating a Conclusion Must restate the _____________ You should _______ or _________ the hypothesis based on data Discuss sources of _____ and how your results were ________ hypothesis accept reject error impacted

Fat Cat a) Formulate a hypothesis b) Create an experiment  You must include two experimental groups and a control group

Determine the variables for Fat Cat a) Identify the control group b) Identify the independent variable c) Identify the dependent variable

Create an Experiment Set up an experiment based on one of following experimental questions 1. “Does the diameter of a ball effect how high a ball will bounce”? OR 2. Does the height of the drop effect the number of bounces?

Muscle Power Joker was told that a certain muscle cream was the newest best thing on the market and claims to double a person’s muscle power when used as part of a muscle-bulding workout. Interested in this product, he buys the special muscle cream and recruits Magneto and Loki to help him. Joker develops a weight- lifting program for Magneto and Loki. He meets with them once every day for a period of 2 weeks and keeps track of their results. Before each session Magneto’s arms and back are lathered in the muscle cream, while Loki’s arms and back are lathered with the regular lotion.

Muscle Power Continued Time Magneto’s Reps Loki’s Reps Initial Amount185 After 1 Week249 After 2 Weeks3317

Bubbles Patrick and SpongeBob love to blow bubbles! Patrick found some Super Bubble Soap at Sail-Mart. The ads claim that Super Bubble Soap will produce bubbles that are twice as big as bubbles made with regular bubble soap. Patrick and SpongeBob made up two samples of bubble solution. One sample was made with 5 oz. of Super Bubble Soap and 5 oz. of water, while the other was made with the same amount of water and 5 oz. of regular bubble soap. Patrick and SpongeBob used their favorite bubble wands to blow 10 different bubbles and did their best to measure the diameter of each one. The results are shown in the chart.

Bubbles Continued

Microwaved Fish Food Thor believes that fish that eat food exposed to microwaves will become smarter and would be able to swim through a maze faster. He decides to perform an experiment by placing fish food in a microwave for 20 seconds. He has the fish swim through a maze and records the time it takes for each one to make it to the end. He feeds the microwaved food to 10 fish and gives regular food mixed with microwaved food to 10 others. After 1 week, he has the fish swim through the maze again and records the times for each fish.

Microwaved Fish Food Continued

What happened to my plants? There is a new fertilizer on the market that claims in increase the amount of water plants are able to take in. I place two plants of the same species in separate containers. I place one plant in a sunny window with the new fertilizer and water it twice a week. I place another plant in a sunny window sill with my regular fertilizer and water it twice a week. a) What should my hypothesis be?

The Microscope

Squidward Continued Based on the data collected, what should Captain America’s conclusion be?

Captain America Example Captain America believes the clarinet attracts more people than any other instrument. To test his hypothesis he played a song on his clarinet for a total of 5 minutes and counted the number of people he saw in his front yard. He played the song a total of 3 times on his clarinet and repeated the experiment using a flute and a guitar. He also recorded the number of jelly fish he observed when he was not playing an instrument.