The Scientific The Scientific MethodMethod

What is the scientific What is the scientific method?method?

A process of gathering facts through A process of gathering facts through observation and formulating observation and formulating scientific hypotheses.scientific hypotheses.

Step 1Step 1

State the problemState the problem

Scientists have a question that they Scientists have a question that they want answered. “Does a smartcar want answered. “Does a smartcar have more momentum with or have more momentum with or without passengers?”without passengers?”

Step 2Step 2

Research the problem.Research the problem. Find as much information about the Find as much information about the

problem as possibleproblem as possible

“ “ find out what affects momentum, find out what affects momentum, how a smart car is made”how a smart car is made”

Step 3Step 3 Make a hypothesis.Make a hypothesis. A hypothesis is an educated guess. A hypothesis is an educated guess. Make a statement based on your Make a statement based on your

prior knowledge or research as to prior knowledge or research as to what you think the answer to your what you think the answer to your question is. question is.

““If a smartcar has more passengers, If a smartcar has more passengers, then it will have more momentum.”then it will have more momentum.”

Step 4Step 4

ProcedureProcedure Design the experiment. Write out a Design the experiment. Write out a

series of steps (directions) and get series of steps (directions) and get necessary materials.necessary materials. Ex: smartcar, road, passengers, scale Ex: smartcar, road, passengers, scale

Step 5Step 5

Complete the experiment, record Complete the experiment, record your datayour data

Step 6Step 6

Analyze your dataAnalyze your data Create a graph of your data, repeat Create a graph of your data, repeat

the experimentthe experiment

Step 7Step 7

ConclusionConclusion Accept, reject, or modify your hypothesis Accept, reject, or modify your hypothesis

based on the analysis of your data.based on the analysis of your data. When a hypothesis has survived When a hypothesis has survived

extensive testing, it may become a extensive testing, it may become a theorytheory

A theory is widely accepted by the A theory is widely accepted by the scientific community and best explains scientific community and best explains observable facts.observable facts.

Parts of an ExperimentParts of an Experiment

Independent variable(IV): variable Independent variable(IV): variable that changes as a result of the that changes as a result of the person doing the experimentperson doing the experiment graphed on the x axisgraphed on the x axis Examples: time (minutes, days)Examples: time (minutes, days)

Dependent variableDependent variable

Is the effect of the independent Is the effect of the independent variable; changes as a result of the variable; changes as a result of the IVIV graphed on y axisgraphed on y axis Examples: temperature, distanceExamples: temperature, distance

Control groupControl group

Part of the experiment that does not Part of the experiment that does not effect the outcome of the effect the outcome of the experiment; not exposed to the experiment; not exposed to the independent variableindependent variable

Ex: passengers vs. no passengersEx: passengers vs. no passengers

ConstantsConstants

The items in an experiment that The items in an experiment that never change so that the results are never change so that the results are not skewed; stays the same not skewed; stays the same throughoutthroughout

Ex: same car, same driver, same Ex: same car, same driver, same roadroad

Practice Question 1Practice Question 1Example: Suzie Q wants to know how different Example: Suzie Q wants to know how different

colors of light effect the growth of plants. She colors of light effect the growth of plants. She believes that plants can survive the best in white believes that plants can survive the best in white light. She buys 5 ferns of the same species, which light. She buys 5 ferns of the same species, which are all approximately the same age and height. are all approximately the same age and height. She places one in white light, one in blue light, She places one in white light, one in blue light, one in green light, one in red light, and one in a one in green light, one in red light, and one in a closet. All of the ferns are planted in Miracle Grow closet. All of the ferns are planted in Miracle Grow and given 20 mL of water once a day for 2 weeks. and given 20 mL of water once a day for 2 weeks. After 2 weeks, Suzie observes the plants and After 2 weeks, Suzie observes the plants and makes measurements.makes measurements.

Independent variable?Independent variable? Dependent Variable?Dependent Variable? Control?Control? Constants?Constants?

Practice #2Practice #2 Laura wanted to see if music had an effect on the Laura wanted to see if music had an effect on the

growth of plants. She took 2 philodendron plants and growth of plants. She took 2 philodendron plants and placed one near a radio and the other one in another placed one near a radio and the other one in another room without a radio. She made sure each plant was room without a radio. She made sure each plant was exposed to the same amount of sunlight each day, exposed to the same amount of sunlight each day, got the same amount of water, and were in the same got the same amount of water, and were in the same kind of pot with the same type of soil. She recorded kind of pot with the same type of soil. She recorded the growth at the same time each day for 2 weeks.the growth at the same time each day for 2 weeks.

Independent variable?Independent variable?Dependent variable?Dependent variable?Constants?Constants?Control?Control?

ReferencesReferences

Smartcar pictureSmartcar picture http://static.ddmcdn.com/gif/smart-car-http://static.ddmcdn.com/gif/smart-car-

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