The Scientific Method involves a series of steps that are used to investigate a natural occurrence.

1.Problem Statement 2.Observation before Experiment/Research 3.Formulate a Hypothesis 4.Experiment 5.Observation 6.Conclusion

Steps of the Scientific Method 1.Problem Statement /Question 1.Problem Statement /Question: a)Uses critical thinking b)Look at facts/Research c)Looks for patterns

Steps of the Scientific Method Research/Observation before Experiment 2. Research/Observation before Experiment: BE OBJECTIVE! a)Find out facts b)Look for patterns

Observation vs. Inference What do you think these words mean? Observations- Inferences-

Observations? Inferences?

Observations? Inferences?

Observations? Inferences?

Do you remember the next step?

Steps of the Scientific Method Formulate a Hypothesis 3. Formulate a Hypothesis: “an educated guess” a.Shows a relationship between the independent and dependent variables. b.Testable prediction c.Explains how/why something works/occurs Example: If soil temperatures rise, then plant growth will increase.

Steps of the Scientific Method Experiment 4. Experiment: An organized procedure for testing a hypothesis. Include a detailed materials list. Step by step procedure

The procedure has TWO specified “groups”

Before we begin explaining- let’s get our brains ready. What do these words mean? Control group Experimental group Constant Dependent variable Independent variable

Why do you need Constants? CONSTANTS -you must control any other variables that may affect your results Ex- if you are testing a fertilizer, you must keep the temp, precipitation, acidity of soil, amount of sunlight etc. constant

Experimental group vs. Control Group There are two kinds of groups in an experiment –Experimental group: The group you are testing Ex- the plants that receive the fertilizer –Control group The group that does not receive the independent variable ex.- the plant that do not receive the fertilizer

Control Group Standard for comparison –To compare the results of your variable group Does NOT contain the Independent VARIABLE –What you are testing Contains all the CONSTANTS –What you are keeping the same Shows that your results are related to the condition being tested. To make sure your results are actually because of your variable

Experimental (Test) Group The group where you actually test the effect of your variable. Contains the experimental variable –Remember: Variables are things that can CHANGE (vary) in an experiment –There are two variables in every experiment…

Independent Variable A.The independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter. B.Plotted on the X axis of a graph C.“Causes” your results

Dependent Variable A. Depends on (will change because of) your independent variable B.Plot on the Y axis of a graph C.Is your results

Example If plant growth and fertilizer are related, then when given fertilizer, plants will grow taller. What is the INDEPENDENT VARIABLE? –fertilizer What is the DEPENDENT VARIABLE? –Plant growth

Hypotheses relate to the variables… The hypothesis is an educated guess about the cause and effect relationship between the independent and dependent variables. -The effect of the INDEPENDENT VARIABLE on the DEPENDENT VARIABLE

A good Experimental Set up Can only test ONE variable (per experimental group) Keeps all controlled variables constant between the groups

Steps of the Scientific Method Observation 5. Observation: a)Results of the experiment b)Recorded as data tables, charts, graphs c)Two kinds…

Kinds of data Quantitative Data: Can be measured. Usually includes a number. Ex: 6 feet tall, 20 cm long “Quantity” Qualitative Data: Descriptions that can be observed but not measured Ex: purple, smelly, sharp “Quality”

Observations cont Do not make assumptions, interpretations or opinions! Should record on what you actually see or measure, etc!

Steps of the Scientific Method Conclusion 6. Conclusion: contains 3 items a)Include a statement that accepts or rejects the hypothesis. b)Summary of experimental results c)Make recommendations for further study and possible improvements to the procedure.

Hierarchy of Scientific Ideas Problem Statement Hypothesis Theory Scientific Law What is the difference? How does each relate to the one below it?

Problem Statement and Hypothesis The problem statement is made before you really figure out how to test it. Often contains a question or words like “I wonder” ex “Why is the sky blue?” The hypothesis is a prediction that is testable and often stated in “if…then” statements.

Theory and Law A theory is a hypothesis which has survived repeated testing. It tells you “why or how” A scientific law is a “rule of nature”. It is often proven mathematically and cannot be disproven. –tells you “what” Theories can be changed, laws cannot! Theories can serve to explain laws –Ex- this ball will fall with an acceleration of 9.8 m/s 2 is the law of acceleration due to gravity. If you want to know why the ball falls, you would use a theory.