1. VARIABLES & SCIENTIFIC METHOD Unit 1 – Intro to Science

2. Variables

3.  There are 3 types of variables  Independent Variable The thing that you change  Dependent Variable The outcome, depend on the independent variable  Controls Things you leave the same, a standard of comparison, not all experiments have controls.

4. Constants  Sometimes these are confused with CONTROLS.  Constants are things that remain consistent throughout the entire experiment.  Temperature, materials, location, etc…

5. Example 1- Independent Variable  Investigating how a weight affects the length of an elastic band.  Independent Variable  The weight applied You decided which weights to use

6. Example 1- Dependent Variable  Investigating how a weight affects the length of an elastic band.  Dependent Variable  Length is the dependent variable. You measure the resulting length of the elastic band

7. Example 2 – Independent Variable  The longer the amount of time spent studying causes an increase in test scores  Independent Variable  Time spent studying You decide how long/much to study for a test.

8. Example 2 – Dependent Variable  The longer the amount of time spent studying causes an increase in test scores  Dependent Variable  Test scores This should change based on how long you study

9. Additional Examples QuestionIndependent Variable (What is changed - Input) Dependent Variable (What is observed - Output) How much water flows through a faucet at different openings? Water faucet opening closed half open fully open Amount of water flowing per minute measured in mL per minute Does heating a cup of water allow it to absorb more sugar? Temperature of water measured in degrees Celcius Amount of sugar that dissolves completely measured in grams

10. Independent Variable The independent variable is always located on the X axis of a graph. It is usually the “X” in a table or equation. The independent variable stands alone (not dependent on anything) The independent variable is what happens first.

11. Dependent Variable The dependent variable is always located on the Y axis of a graph. It is usually the “Y” in a table or equation. The dependent variable DEPENDS on the independent variable. The dependent variable is what happens second.

12. Unit 1 – Intro to Science Scientific Method

13. Science  “Sci” means “to know”  We know things from facts that can be proven through data and evidence  We gather facts through the scientific method.  The Scientific Method  A pattern that scientist use to investigate or solve a specific problem.

14. Steps in the Scientific Method 1. Identify a problem 2. Research the problem 3. Develop a hypothesis 4. Design experiment (Independent and Dependent) 5. Test/Conduct the Experiment 6. Analyze the Results 7. Form Conclusions 8. Repeat / Publish

15. Example 1  Identify a problem  Noticing that many salamanders near a pond have curved, not straight tails.

16. Example 1  Research the Problem  Go to library and research reputable journals.  Research using internet but only trustworthy sources.  Prior knowledge or experience

17. Example 1  Develop a Hypothesis  A hypothesis is a possible explanation for a set of observations or answer to scientific question, predicts an outcome  Should be written as “I think _______ because______.”

18. Example 1  Design an Experiment  Is a test made up of variables that can be tested or compared. There are 3 types of variables in an experiment.

19. Example 1  Carry out experiment  Make observations during the experiment  Types of observations Quantitative (Quantity) Using numbers Qualitative (Quality) Descriptive Using your 5 senses (touch, smell, etc.

20. Example 1  Analyze Data  Charts  Graphs  Tables  Averages  Visual Ratings Bar Graphs, Line Graphs normally used.

21. Example 1  Form a conclusion  We summarize what the data (tables, charts and graphs) reveals.  Discuss any changes you may want to make in your experiment and why.