S c i e n t i f i c M e t h o d s

Your Job Write down everything in BLUE!!!

How have we come to know so much about science? Solving Problems Answering Questions

How can understanding scientific methods be useful to you? Learn how to formulate strategies to answer questions you will encounter in your own scientific studies or daily lives.

Ask a question… Who What Where When Why

Background Research! Observe Look at similar studies Find out if the experiment is worth running

Form a Hypothesis After observations & research… Create a statement that explains the observations and can be tested!

Usually a “if-then” statement Hypothesis: A statement that predicts in advance the results that will come from testing the hypothesis. Usually a “if-then” statement If different potting soils are compared and tested for water holding capacity, then it will be shown that potting soil A will be more effective that potting soil B.

Variables and Terms Experimental Unit- The value being manipulated or changed (different breeds of sheep, different plant varieties, different potting soil.) Variables: Factors that change Independent Variable (manipulated)- The manipulated experimental unit. Dependent Variable (responding)- the results, the data, number, quantitative/qualitative data you collect Control/Constant- The experimental unit that you are not manipulating, or the constant in your experiment, something that doesn’t vary from subject to subject.

Example Experimental Unit: Dependent Variable: Independent Variable: Control/Constants: Chicken feed trial!

Experiment Randomization- Randomize as often as possible when assigning treatments to experimental units. Eliminates bias. Replication- Replicate entire experiment at least twice.

Analyze Data Does data support the hypothesis? What were the variables? Are there sources of error?

Draw a Conclusion Shed light on something previously not understood!

Make an Inference A conclusion based on facts rather than observations Inferences can’t always be tested

Form a Theory This is not a “wild guess” or a hypothesis Theories- well tested explanations for a broad set of observations “Can never be proved”-meaning we are leaving open the possibility that a theory may be changed at some point in the future. Scientific Law- concise statement that summarizes the results of many observations and experiments.

Steps of the Scientific Method:

Bubble Gum Experiment!