The Scientific Method
The Nine Steps of the Scientific Method 1. 2. 3. 4. 5. 6. 7. 8. 9.
Questioning Controlling Variables Making a hypothesis Planning Performing Observing Analyzing Evaluating Communicating
1) Asking a question • • • • •
Semi-formal Similar to brainstorming Question should interest you Question can be about anything E.g. Are taller people better at basketball than shorter people?
2) Controlling the variables • Variables are factors that can affect the outcome of an investigation: 1) Independent variable – variable that is changed 2) Dependent variable – variable that is affected by the independent variable 3) Controlled/Standardizing variable – variable that remains unchanged and does not affect the outcome 4) Control Group – Group that is not changed, normal conditions used to compare results
3) Making a hypothesis • Is a tentative answer about the outcome of a controlled experiment along with an explanation for the outcome • Should be presented in an “if / then / because” statement • Should indicate cause and effect relationship • Can usually be derived directly from your original question • Is an educated guess • Should be only a single sentence • Must be feasibly testable • E.g. If someone is taller then they will be better at basketball because they are closer to the net.
4) Planning • Identify all your variables • Consider equipment and materials • Write a clear procedure
Writing a procedure
• A procedure is a sequential list of steps that are to be followed exactly during an experiment. Steps should be in order and numbered. • Hints: Be specific, be exact, watch your language. • Try this: – In a group of 2, write up a procedure for washing your hands. Starting from dry and hands and ending with dry hands.
5) Performing the experiment • Follow procedures exactly, if procedures are unclear ask • Be safe • Record which variables are being changed and how they are being changed • Repeat experiment a minimum of three times. (Why?) • Make careful notes of everything that occurs during your experiment, in addition to the data filling in charts and tables. Note possible sources of error
6) Observing and recording data • Record all data/observations in an appropriate form. (Charts or tables are most common) • Record all data as clearly and accurately as possible • Make careful notes of everything that occurs during your experiment, in addition to the data filling in charts and tables. Note possible sources of error • Note anything that happens the same or differently each time, as well as anything that might have changed from one experiment to the next • Note possible sources of error in the experiment
7) Organizing and analyzing results • When possible create graphs to represent numerical data, as it is easer to read and understand for others • Identify patterns and trends in results • Make conclusions • Determine if your hypothesis is supported by the results
8) Evaluating/Conclusion • How useful is the evidence? • Determine if your hypothesis was correct
9) Communicating • Share your process and finding with others by writing a report