1. The Scientific Method

2. Steps of Scientific Method 1.Observation: notice and describe events or processes 2.Make a question 1.Relate to observation 2.Should lead to an experiment 3.Inference- logical interpretation based on what already know 1.Requires research 2.Leads to a hypothesis

3. Steps of scientific method (Cont’d) 4.Hypothesis- a prediction of what will happen based on scientific reasoning If (change something), then (outcome ) will result. After a hypothesis, explain your prediction.

4. Review I notice my grades are higher this year compared to last year

5. Steps of the scientific method: cont’d 5.Design controlled experiment - Includes 1.Control- same conditions as rest of experiment except you don’t change up the independent variable 1.Used for comparison 2.Independent Variable- Variable the scientist changes up (not dependent on anything else) 1.‘If’ part of hypothesis 3.Dependent Variable- The results of the experiment (relies on independent variable) 1.‘Then’ part of hypothesis

6. Things to Avoid! Bias- design a lab so that results are no longer objective Placebo effect- the subject reacts as if they have received treatment when they have really not Blind trials for subject/scientist- the subject/scientist does not know the treatment receiving

7. Sample Size Small sample sizes result in bias of results! Fewer samples, subject with ‘odd’ results skews your results

8. Number of Trials Small number of trials causes bias Fewer trials, experiments with ‘odd’ results skews your results

9. Steps of the Scientific Method: Cont’d 6. Collect Data –Quantitative Data Measure the amount (this will be a number) The solution had a pH of 7 –Qualitative Data Description of results Example: After performing the Benedict’s Test, the solution turned a brown color

10. The Scientific Method: Cont’d 7. Analyze Data: Statistics Mean –Average –Add values, divide by total # of values 5,10, 15, 10, 12, 13 Mean:

11. Setting Up A Table Amount of Sunlight (hours) Plant Growth (cm) 220 1050 Independent variable goes in the left column Units are included Dependent variable goes In right column Units are included Remember! 1. ONLY INCLUDE MEANS IN TABLE, NO RAW DATA! 2. DO NOT PUT UNITS IN AFTER EACH DATA POINT!

12. Graphing Bar Graph or Histogram Used for comparison Data separated into categories –Examples: red, blond, brown hair Line Graph Used to determine relationship between variables Data is continuous –Examples: Height, pH, temperature

13. How to Make a Graph Scale: takes up most of space

14. Analyzing Tables & Graphs 1.Direct Relationship –As x increases, y increases 2.No Relationship –As x increases, no change in y 3.Inverse Relationship –As x increases, y decreases

15. Analyzing Tables and Graphs 4.Cyclical Relationship 5. Normal Distribution

16. Explanations 1.Make a claim- statement or explanation –This is your conclusion 2.Provide evidence to support your claim (from your results) 3.Describe factors that could be sources of error 4.Discuss future experiments that could stem from the one you just completed

17. Check the Validity of Your Experiment Repeat your experiment Check your experimental results with scientists who performed the same experiment as you

19. Theories & Laws Theory Claim that is supported by many different types of experiments Dominant view among scientists NOT the absolute truth Examples: Law Claim that is considered to be the truth Examples:

20. Communication in Science Spoken –Conferences –Lectures –Informal conversations Written –Journal articles –Peer review

21. Peer Review Other scientists check your work Questions to ask Hypothesis –If, then, because Experimental design –Sample size, bias, matches with hypothesis Results –Tables/graphs contain all elements, clear, & accurate –No interpretation in results Discussion –Claims supported by evidence –Indicates sources of error –Describes potential new experiments