The Scientific Method Mr. Williams Earth Science

What is the Scientific Method? A Systematic Approach to Problem Solving A method that is applied in all scientific investigations

Steps of the Scientific Method State the Problem (Purpose) Research (Gather information on the problem) Form a hypothesis Perform experiment(s) to test the hypothesis. Record and analyze data State a conclusion Repeat and/or redesign

State the Problem This is the purpose of the investigation State what problem you want to solve or what question you want to answer

Research (Gather Information) Use various resources to inform yourself about the parts of your investigation You must educate yourself about your investigation so you can make an “educated guess” to test

Develop a Hypothesis A hypothesis is an educated guess It proposes an answer to your question or a solution to your problem The hypothesis is what you are testing in an investigation Let’s choose an example and work through the first three steps of the scientific method together

My truck will not start!!! What’s the problem? How can we gather information about the problem? What are some possible hypotheses we could investigate?

Perform the Experiment Design and perform an experiment that will test your hypothesis for accuracy To do this you must be able to identify your variables

Variables Independent Variable The thing that is being changed by you-that you are manipulating There can only be ONE changed variable Dependent Variable The “thing” that responds to what you have changed or manipulated This is the thing you are measuring

One More Type of Variable Control Variable These are the things that stay the same throughout the investigation or experiment In the setup of your experiment, you can only have one changed variable; this means all other variables must be controlled.

Back to the Car... Possible hypothesis: If gas is put into the car, the car will start. What is the manipulated or changed variable? What are some controlled variables? What is the responding variable?

Record and Analyze Data Data includes the measurements and/or observations you make about the responding variable But first, you must determine what type of data (called observations) you will collect

Types of Observations Quantitative Observations that measure such things as size, weight, distance, volume etc. This observation MUST use a number Qualitative Observations that describe using details such as size, color, shape This observation uses NO numbers

Examples Quantitative Jane is 5 feet tall There are 65 cars on the train I wear a size 12 shoe The gas tank holds 18 gallons Qualitative Jane is taller than Jack The walls are yellow Oranges are round Jack is older than Jane

Quantitative or Qualitative? Which type of observation is most useful in a science investigation? QUANTITATIVE!! Why?

State the Conclusion Your conclusions should consist of your best explanations for given observations Your conclusion should answer the question: What happened? And Why did it happen?

Repeat and/or Redesign In order to confirm results, you should always repeat your experiments numerous times. If there are ways to improve your experiment, you should redesign it until it properly tests your hypothesis Remember! A single experiment never “proves” a hypothesis to be true, it only supports or does not support a hypothesis

Remembering the Steps Try this pneumonic device: Sally gave Fred Patrick Richardson some roses Or develop your own

Back to the Car Again How would we perform the experiment to test our hypothesis? (If gas is put into the car, it will start.) How would we collect and analyze our data? If the car starts, what can we conclude? If the car doesn’t start, what can we conclude? How could we redesign our experiment to find out why the car won’t start?

Let’s Apply What You’ve Learned Are You ready? Start your Brains.

Apply what you’ve learned.... To test whether aspirin can keep flowers fresher for a longer period of time, take two large beakers (labeled A and B) with equal amounts of water. Place one red carnation in each beaker. In beaker A, put one tablet of aspirin. In beaker B do not put aspirin. Identify the following in regard to this particular experiment. Identify the Independent Variable Amount of WaterAspirin CarnationsTime the flowers stay fresh

Apply what you’ve learned..... To test whether aspirin can keep flowers fresher for a longer period of time, take two large beakers (labeled A and B) with equal amounts of water. Place one red carnation in each beaker. In beaker A, put one tablet of aspirin. In beaker B do not put aspirin. Identify the following in regard to this particular experiment. What is the Dependent Variable? Amount of waterSize of Beakers Size of CarnationsTime flowers stay fresh

Apply what you’ve learned.... “If the amount of sunlight available increases, the rate of photosynthesis in a plant will also increase.” This statement is an example of a(n): ConclusionPurpose AnalysisHypothesis

Apply what you’ve learned.... The effect of one minute of walking and one minute of running on the pulse and respiration rates of a human. SpeedTime Pulse & Respiration RatesWalking & Running

Apply what you’ve learned.... If you were doing research on the deadly E-bola virus, which resource in the library would give the most current information? InternetBook World Book EncyclopediaReaders Guide

Apply what you’ve learned.... The effect of one minute of walking and one minute of running on the pulse and respiration rates of a human. In this experiment, what are the Controlled Variables? SpeedTime Pulse & Respiration RateWalking & Running

Apply what you’ve learned.... A student plants one marigold seed into each of three pots. One pot she uses soil from a flower bed outside her house, one pot she plants with soil from a garden store, and one she plants into rocks. She uses a pitcher and waters each seed. She puts a pot on the window sill of her kitchen, one under the grow lights on her porch and one in a bag. She waits three days and makes her first observation. This not a well prepared experiment, on a sheet of paper, write at least three reasons why this is not a scientifically sound experiment