Scientific Method

Steps of the Scientific Method Question Research Hypothesis AnalysisConclusion Investigation/ Experiment

Scientific Method 1. Starts with a QUESTION –How do I make a PB & J sandwich? 2. HYPOTHESIS—educated prediction of the outcome –Always in the form of a specific statement (complete sentence) –I believe that these are the steps to making a PB & J: (1) take two pieces of bread from the bag, (2) etc.

Scientific Method (ctd.) 3. EXPERIMENT—test your hypothesis –Try to make a PB & J using the directions in your hypothesis 4. ANALYSIS—look at the data that you gathered and decide what that data means –Could you make a PB & J using your instructions? 5. CONCLUSION—was your hypothesis correct? –If not, use the information you gathered to construct a new hypothesis and conduct a new experiment

Using the Scientific Method QUESTION HYPOTHESIS EXPERIMENT ANALYSIS CONCLUSION

Vocabulary Experiment: artificial situation in which the investigator controls the factors that could affect the outcome Variable: the factor that might affect the outcome Control: the factor that has NO affect on the outcome and is only used for comparison during an experiment

Kinds of Variables INDEPENDENT Controlled by the experimenter CONTROL VARIABLE The experimenter makes a special effort to keep other factors constant so that they will not effect the outcome. Those factors are called control variables. DEPENDENT Responds to and measures changes in the independent variable.

Collect / Organize Data Once you collect data, you need to organize it into a data table and/ or a graph. Independent Variable Dependent Variable

Identifying Variables Situation: You are investigating the body temperature of a frog at different times of day. You decide to take a temperature reading in the morning, at noon, at night, and midnight.

Independent variable is….time because you are controlling the times it is being collected. Dependent variable is... The frog’s body temperature. You have no control over the frog’s body temperature; you are simply observing it.

Setting Up a Controlled Experiment What is the QUESTION? HYPOTHESIS Identify the INDEPENDENT VARIABLE(S) Identify the DEPENDENT VARIABLE Identify the CONTROL How will you collect data

Controlled Experiments You have been asked to test the effectiveness of a new waterproof mascara Control? Independent variable? Dependent variable?

You have been asked to test the effectiveness of a new teeth whitener Control? Independent variable? Dependent variable?

You have been asked to test the effectiveness of a new fuel additive. Control? Independent variable? Dependent variable?