How do Scientists Solve Their Problems?

How do Scientists Solve Their Problems? Catalyst: Read and Respond. “Hurricane Irene will likely hit NYC, scientists say… New Yorkers prepare for the worst” -The New York Times (8/25/11) Is it ok to just accept what scientists say? What reasons do we have to believe them?

Words of The Day Hypothesis- prediction tested in an experiment Independent Variable- THING experimenter is testing or changing Dependent Variable- what is measured during an experiment (Data)

The Scientific Method

What is the Scientific Method? • The series of steps that biologists and other scientists use to gather information and answer questions. • There are 6 STEPS!

Step 1: Ask a Question • Ask a question that can be answered through an experiment.

Step 1: Ask a Question • Ask a question that can be answered through an experiment. • Example: What happens if I only eat McDonald’s for a week?

Step 1: Ask a Question • Ask a question that can be answered through an experiment. • Example: What happens if I only eat Mc Donald’s for a week? • Do not ask questions that CANNOT BE TESTED.

Step 1: Ask a Question • Ask a question that can be answered through an experiment. • Example: What happens if I only eat Mc Donald’s for a week? • Do not ask questions that CANNOT BE TESTED. • Example: Is there a God?

Step 2: Observation/Research • Make observations and research your topic/question.

Step 2: Observation/Research • Make observations and research your topic/question. • Example: Research the fat content of McDonald’s food

Step 3: Hypothesis • Predict a possible answer to the problem or question.

Step 3: Hypothesis • Predict a possible answer to the problem or question. • Example: IfI eat McDonalds for a week, thenI will gain five pounds.

Step 4: Experiment • Develop and follow a procedure where you can measure something. • Don’t forget a materials list!

Step 4: Experiment • Develop and follow a procedure where you can measure something. • Don’t forget a materials list! • Example: Eat McDonalds meals for lunch and dinner every day for 7 consecutive days. Weigh yourself at the beginning of the week and at the end of the week.

Step 5: Collect/Analyze Results • Collect the data in a table or graph. • See what your results are.

Step 6: Conclusion • Accept or reject your original hypothesis based on your results. • Make recommendations for further study. • Possible improvements to the procedure.

Experimental Variables 3 kinds of variables in every experiment:

Experimental Variables 3 kinds of variables in every experiment 1. Independent Variable • The thing that is changed by the scientist • It is what is tested • Example: Eating McDonalds

Experimental Variables 2. Dependent Variable • The thing that is affected by the independent variable • What is measured, or observed • Example: How much you weigh

Experimental Variables 3. Control Variable • The variable or variables that are NOT changed during an experiment • They allow for “fair tests” • Example: The only difference in your life is eating McDonalds, everything else you do the same are controls...

Control vs. Experimental Group Experimental Group:group that receives what is being tested group t Control Group:group where nothing is changed and that serves as a comparison to the Experimental Groupis being tested

Ms. Webb wants to know if a new brand of sneakers can help our cheerleaders jump higher as they cheer on the Bulldogs. She gave out new Nikes, Adidas, or Reeboks to most of the girls and the rest of the squad wore the old, non-name brand sneakers. Then she measured each girl’s jump height and took the average for each shoe type.

Hypothesis- Independent Variable- Dependent Variable-

A study was designed to determine if a chemical called antirosaprevents conjunctivitis (pink eye). 10,000 individuals were divided into four groups. Each person took a pink pill every morning for one year. Some patients received 3 grams of antirosa, some received 6 grams of antirosa, some received 9g of antirosa and some received a sugar pill. Then the number of times patients developed conjunctivitis was measured. • Hypothesis: • Independent Variable: • Dependent Variable:

Experiment 1: The Metro is flat broke. It wants to test the effect of several kinds of music on subway use. It will play classical music over the loudspeakers on the A, hip-hop on the 4, country on the 2 etc. Then it will look to see if the number of people that take that line changes. State the hypothesis- Identify the independent variable- Identify the dependent variable-

Experiment 2: Mr. Tejwani is addicted to Dunkin Donuts coffee. However, he also loves sleeping in and doesn’t want to get up extra early to get it. He could go to the Dunkin by his apartment, the one by the Nationals stadium stop, or the one off MLK Blvd. He decides to test each route to see which adds the least time to his morning commute. Identify the independent variable- Identify the dependent variable-

Experiment 3: Creatan is a new drug being studied as a treatment for shortness of breath. In a study with 400 people, 200 people received creatan pills and 200 people received sugar pills as placebos. The patients treated with creatan showed an increase in the distance they could walk before they became short of breath. • state the hypothesis to be tested in the experiment • identify the dependent variable in the experiment • state whether the data supports or fails to support the hypothesis and justify your answer

Experiment 4 A certain plant has white flower petals and it usually grows in soil with a lower pH (more acidic soil). Sometimes the plant produces flowers with red petals. A company that sells the plant wants to know if soil pH affects the color of the petals in this plant. • state the hypothesis to be tested in the experiment • identify the dependent variable in the experiment

BREAK

Control Group • A group where nothing is tested, everything is kept normal. • Why???? To have something to compare the experiment to. • Example: Weigh someone at the beginning and end of 7 days, that does NOT eat McDonalds, he/she just continues their normal diet.

A Safer Cigarette? • State the hypothesis that local researchers are testing • Identify the independent variable in the experiment • Identify the dependent variable in the experiment • Why did the experiment include 5,000 smokers who were not using the e-cigarette?

How do Scientists Solve Their Problems?