OHHS Scientific Investigation Design
- Ask a QUESTION
Include both the manipulated and responding variable. What is the effect of the "manipulated variable" on the "responding" (dependent) variable?
- Make a PREDICTION (Hypothesis)
Provide a cause-effect reason for the responding variable to behave as predicted. If the "manipulated variable" increases/decreases, the "responding" variable will increase/decrease, because...
- Design an EXPERIMENT
- Detailed Procedure
- One manipulated variable (independent) - state at what interval or how the manipulated variable will be changed.
- One responding variable (dependent) - state at what intervals or when the responding variable will be measured.
- Identify at least two controlled variables (kept the same).
- Identify an experimental control to serve as a basis of comparison.
- Include repeated trials. The procedure should be carried out more than just once.
- Account for issues affecting validity, for example cleaning equipment between trials.
- Be specific enough that someone else who reads your procedure and repeated your investigation would likely get the same results.
Use a data table to record results. Describe the trend of the data. As appropriate, determine the mean, median or mode. Use a line graph (continuous variables), bar chart (discrete variables), pie chart or diagram to help interpret your results.
- Answer the question or respond to the hypothesis. Support your conclusion with data. Include high and low data points. Explain how this data supports the conclusion.
- Always quote data accurately.
- Evaluate your work (quality control).
- What new questions might you ask?