The Scientific Method and Forensic Science Object: 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 Create an experimental question based on the activity we did in class. Label the procedure in your NB How did you organize your data? Why?

Steps of the Scientific Method 1. 2. 3. 4. 5.

Hypothesis Is an attempt to ________ something. Must: Include a ________ E.x Be able to be _________ Be written as a _________ Is an attempt to explain something. Include a condition. Be able to be tested and falsified. Be written as a statement.

Which of the following would be considered a hypothesis? Hyperactivity is unrelated to eating sugar. If you get 6 hours of sleep, you will do better on tests. 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 do you need to know about Easter Island (Rapa Nui)?

The Walking Moai of Easter Island The island was once filled with palm trees Draft animals and wheels were not used Most of the statues weighed five tons Most statues have wider bases than shoulders According to legend the Moai “walked” Palm trees are essentially a hardwood with soft foamy material inside.

The Answer http://www.youtube.com/watch?v=J5YR0uqPAI8

Creating An Experiment How many variables should be tested? How many “groups” need to be included? You should only test one variable. You must include a control group and at least one experimental group.

The Control Group What is the control group used for? Does the control group get the “treatment”? E.x. The control is used to compare against experimental groups. The control is not changed.

Variables. Independent variable: Dependent variable: E.x. The independent variable is the variable that changes. The dependent variable is the variable that is EFFECTED by the change.

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. Identify the control variable Identify the independent variable Identify the dependent variable

Scooby Identify the following: Independent variable: Observation: I normally 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: Independent variable: Dependent Variable: The Control:

Effect of Soap on Surface Tension Analysis Identify the control group  Identify the independent variable Identify the dependent variable Did we set up our experiment correctly? Explain your answer. 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. Create a hypothesis Set up an experiment to test your hypothesis. You must include an experimental group and a control group. Identify the independent variable and the dependent variable.

Creating an Experiment Set up an experiment based on the experiment question “Does the diameter of a ball effect how high a ball will bounce”?

The Microscope

Fat Cat Formulate a hypothesis Create an experiment Form a Conclusion Remember you must have two experimental groups and a control group Form a Conclusion

Determine the variables for Fat Cat Identify the control group Identify the independent variable Identify the dependent variable

Data Analysis Look for a significant __________ in the dependent variable Compare the ________ group to the experiment group

Formulating a Conclusion Should restate the _____________ You should _______ or _________ the hypothesis based on your data Discuss sources of ____________ error. You should restate the hypothesis. You should accept or reject the hypotheis based on your data. Discuss sources of error and how they impacted your results.

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.

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

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 Amount 18 5 After 1 Week 24 9 After 2 Weeks 33 17

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. What should my hypothesis be?

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

What is Forensic Science? The application of __________ to __________ Was first used in third century China. How? The application of science to law.

Anthropometry A series of _________ used to __________ Measurements used to identify people

How accurate is Anthropometry? Take the following measurements from 3 different students and compare your results Name: Chin to top of head Elbow to wrist Arm span Analysis: Did anyone end up with the exact same measurements? Based on your results is anthropometry an accurate system of identification?

Mug shot Are used to __________ a suspect How?

What can you tell me about this man?

Are these mug shots useful? Why or why not?

What can you tell me about this woman?

Locard’s Exchange Principle States when ______ or more objects make _________, material is ___________.

Which examples show Locard’s Exchange Principle?

Alphonse Bertillion Created anthropometry and the ______ ______

Principles of Science _______ in the natural world have ________ ___________ E.x.

Principles of Science (Continued) Uniformity- laws of nature _______ the ______ ____ in all places E.x.

Theory vs Law Theory- summarizes a group of _________ that are supported by __________ Law – generalizes several _________ Must be ________ E.x.

Decide whether the statement is a theory or a law For every action there is an equal and opposite reaction A change in the inherited characteristics of a population Energy can be changed but it cannot be created or destroyed All living things are made of cells

Summary Question(s) Why is evolution considered a theory and not a law? Identify the independent and dependent variables in the pig experiment

Summary Questions Why is anthropometry not an accurate way to identify an individual? Why are mug shots a useful in an investigation?

T-Shirt Lab Review What was the independent variable in Friday’s lab? What was the dependent variable? How did you apply the steps of the scientific method in Friday’s lab?