Scientific Method—designing an experiment.

State the problem The question the scientist is trying to answer

Propose a hypothesis an educated guess to predict a possible answer to problem based on research, previous knowledge, observations, and information from studying a problem

Test hypothesis design an experiment to test hypothesis Controlled experiment = tests only one* changing factor or variable,other parts remain the same control group* = does not change during testing, compared to experimental results experimental group = contains change being tested Manipulated or independent variable = what you change (becomes experimental group) Responding or dependent variable = what you measure, depends on other variable

Make observations data that is recorded in an organized manner, include measurements, observations with senses and instruments, organized in diagrams, tables, charts, graphs, equations, and matrices Inference: your judgment based on an observation

Analyze Data Interpret what the data means for example by graphing or using calculations

State a conclusion review data from observations to determine if data supports hypothesis and to develop additional hypotheses, generalizations or explanations hypothesis are either supported or rejected (not proven)

Repeat the experiment In a good experiment another person needs to be able to repeat the experiment and get very similar results. Many scientists repeatedly test the experiment to ensure conclusions are supported and may become a scientific law a. Facts = based on experiments and careful observations b. Theories = scientific hypotheses that have been tested many times and confirmed by many scientists c. Scientific law = result of many scientists repeatedly reaching the same conclusions

“OPHEACR” The Scientific Method O = observe P = problem to solve H = hypothesis E = experiment and record data A = analyze data C = conclusions R = repeat and continue research “OPHEACR”