The scientific method is an organized way to solve a problem

Intro to the Scientific Method We use the scientific method EVERY DAY! We follow a series of steps to carry out the scientific method. Observation Conclusion Question Hypothesis Results Procedure

Steps of the Scientific Method State the problem Formulate a question that needs to be answered, based on OBSERVATIONS, not INFERENCES. O: Why are all these birds dead? I: How did pollution kill these birds? O: What is this giant hole? I: How long ago did get a meteor land here?

Steps of the Scientific Method 2. Propose a hypothesis A hypothesis is an educated guess about what the solution to the problem is. We typically use an “if…then…” statement. If a meteor hits earth, then it will create a crater. If there is an excess of pollution, then animals will die.

Steps of the Scientific Method 3. Test the hypothesis – write a procedure. Testing is done through experimentation. All experiments should contain a variable or a condition which can be changed. Experiments also include a control in which no change is made. The control serves as the reference Miracle Grow Hypothesis: If I add Miracle Grow, then my plants will grow faster. Water VARIABLE CONTROL Plant A Plant B

Steps of the Scientific Method There are two main types of variables. Independent variable – the variable you CHANGE Dependent variable – the variable you MEASURE Hey, listen. Everything in your experiment should be kept the same except the variable your changing. We call these constants, dude. Plant A Plant B

Steps of the Scientific Method When testing your hypothesis, be sure to write out a detailed procedure of how your experiment will go. Procedure: Step 1: Get two plants of same size, label them Plant A & B Step 2: Expose plants to same conditions Step 3: Add 50mL of water to plant A each day Step 4: Add 50mL of Miracle Grow to plant B each day

Steps of the Scientific Method 4. Observations and data. The results of the experiment are recorded as data. We put these results in a data table. To determine data, observations are made with our senses and instruments Test Tube Color Change Occured Color Change Did Not Occur a x b c d

Steps of the Scientific Method Data can also be represented on a GRAPH - Dependent variable goes on Y axis - Independent variable goes on X axis DEPENDENT INDEPENDENT

Steps of the Scientific Method 5. Analysis & Conclusions The data from the experiment needs to be looked at and analyzed. After this is done, a conclusion or answer to the problem

Steps of the Scientific Method 6. Report & Repeat Conclusions must be reported so that other scientists can repeat the experiments Video – This scientific method won’t be repeated 

How to Increase Validity How can you ensure that your experiment is valid? Run multiple trials Test more subjects Pete and Repeat are in a boat. Pete falls out. Who’s left?

Laws & Theories When a hypothesis has been put through the steps over and over again, yielding the same result with no exceptions, it may become scientific theory (ex. Theory of Evolution, Theory of Relativity)

Laws & Theories A scientific law generalizes a body of observations. There are no exceptions to a law. Scientific laws explain things, but they do not describe them. A law “just is”. (ex. Law of Gravity)

Examples Problem #1 Observation: You notice people who take off their shoes during tests achieve higher grades. What would a hypothesis be? How would you test this? What is the independent variable? What is the dependent variable?

Examples Problem #2 Observation: You notice that people who own pets tend to be happier. What would a hypothesis be? How would you test this? What is the independent variable? What is the dependent variable? What is the control?

Examples Problem #3 Observation: You notice that people tend to pass more gas after eating high protein diets. What would a hypothesis be? How would you test this? What is the independent variable? What is the dependent variable? What is the control?