Scientific Method

Scientific Method Scientific method: An orderly, systematic method for solving problems. 1. Identify a problem 2. State observations about the problem 3. Form a hypothesis about the problem (if…then…) 4. Design an experiment to test the hypothesis 5. Collect data 6. Form a conclusion 7. Retest

Germinating Bean Experiment 1. Problem: ________________________________________________ 2. Observations:

Hypothesis Theory Hypothesis Versus Theory a well-established and highly reliable explanation, but may be subject to change as new areas of science and new technologies are developed. Hypothesis a tentative and testable statement that must be capable of being supported or not supported by evidence.

Experiment 1. A good experiment will only have ONE variable that is changed. 2. An experimenter changes one factor and observes or measures what happens. 3. It is best to make several trials.

Controls and Variables Independent Variable - IV: the independent variable is the situation the scientist manipulates. (X axis) Dependent Variable - DV: the dependent variable changes in response to the IV and provides the data measured by the scientist. (Y axis) Constants: These conditions must stay the same so they won’t interfere with the test results. Control Group: Results from experimental group are compared to this.

Controls and Variables Bean Experiment: Independent Variable - IV: Solution type 2. Dependent Variable - DV: plant growth 3. Constants: type of bean, amount of liquid, cup, paper towel, intensity and duration of light 4. Control Group: Results from experimental group are compared to this.

Data – Quantitative & Qualitative 1. Results of the experiment 2. May be quantitative (numbers) or qualitative 3. Qualitative: includes descriptions of observations made during the experiment. i. It can also include drawings, sketches or side notes similar to what you would write in a journal. 4. Quantitative: Number data from measurements a scientist takes during an experiment is logged into a data table and translated into the appropriate graph.

1. Albert Einstein was the greatest scientist in history. Review: Hypothesis or Not? 1. Albert Einstein was the greatest scientist in history. i. No. This is an opinion & cannot be tested. 2. If a person takes vitamins each day, they will be healthier. i. No. Cannot measure “healthier.” If more specific, such as “will have less cholesterol” and specified which vitamin, then it could be tested. Answer: Not. This is an opinion and not something that could be tested.

Review: Hypothesis or Not? 3. If a person plays the lottery, they will become rich. i. No. This is a prediction, not a testable statement. 4. Children who don’t watch TV are smarter than children who do watch TV. i. No. Too general; could not be tested. “Smartness” is too general, as well as “children who watch TV.” If more specific, i.e.: “Children who watch more than 10 hours a week of TV will score less on the state achievement test than children who watch less than 10 hours a week of TV,” then it could be tested. Answer: Not. This is an opinion and not something that could be tested.

Review: Hypothesis or Not? 5. Bacteria will grow more quickly in a warm environment than a cold environment. i. Yes. This is testable and has a clearly identifiable independent variable (temperature) and dependent variable (bacteria growth). 6. A plant grown with salt added to its soil will be shorter than a plant grown with no salt added to its soil. i. Yes. It has a clear independent variable (salt or no salt in soil) and dependent variable (plant height). Answer: Not. This is an opinion and not something that could be tested.