Scientific Method

What is it? A systematic approach to problem solving It’s applied to ALL Scientific investigations!

The 8 Steps are: State the Problem (or a question) Research (background information) Form a hypothesis Design and conduct experiment(s) to test the hypothesis. Record & Analyze Data/Results State a conclusion Reflection – Repeat/Redesign Report – peer review

State the Problem What question do you want to answer? You do not have to reinvent the Wheel!

Research 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 Hypothesis is an “educated guess” It proposes an answer to your question or a solution to your problem Hypothesis what you are testing

Example using 1st 3 steps… Problem: The car won’t start Research: How can we investigate this problem? Hypothesis: what is your educated guess?

Experiment You must design and perform an experiment that will test your hypothesis, this is done to validate or support on not support the hypothesis. 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

Constant Variable These are the things that stay the same throughout the investigation or experiment Since you can only have one changed variable everything else must stay the same

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 constant variables? What is the responding variable?

Results: Record and Analyze Data Data includes the measurements and/or observations that you made about your responding variable you must determine what type of data you will collect….

Types of Data Quantitative Observations that measure such things as size, weight, distance, volume etc. This observation uses a number Qualitative Observations that describe using details such as size, color, shape They do not use numbers

Examples Quantitative I am 5’3” He wears a size 12 shoe The gas tank holds 18 gallons There are 100 classrooms in this school Qualitative Jane has blond hair The walls are white Oranges are round Jack is older than Jane

Which one is more useful ? Why?

Conclusion This should be your BEST explanation for your observations Your conclusion should answer “what happened?” and “why did it happen?”

Reflection How could you make your experiment better? Provide details in your experimental design? What would you change if you were to do the experiment again? Remember: A single experiment never “proves” a hypothesis - it only “supports” or “does not support” the hypothesis

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 Water Aspirin Carnations Time 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 water Size of Beakers Size of Carnations Time 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): Conclusion Purpose Analysis Hypothesis

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. Speed Time Pulse & Respiration Rates Walking & 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? Internet Book World Book Encyclopedia Readers 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? Speed Time Pulse & Respiration Rate Walking & 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