Scientific Method Study Guide

Scientific Method

Overview

The scientific method is a logical approach to problem-solving or answering questions about the natural world through observation and experimentation.

Steps of the Scientific Method

1. Observation: Identifying the problem.

   • Example: Fish swim slower in cold water.

2. Question: Asking a testable question about the observation.

   • Example: Does water temperature affect fish activity?

3. Hypothesis: Creating a testable and falsifiable explanation that answers the question.

   • Example: If water temperature increases, then fish will swim faster.

4. Experiment: Performing a test to prove the hypothesis right or wrong.

   • Independent variable: The factor being manipulated; e.g., water temperature (cold vs. warm).
   • Dependent variable: The factor being measured; e.g., fish swimming speed.
   • Constants: Factors kept the same to ensure a fair test; e.g., same type of fish, same size tank, same amount of food, same time of day.
   • Control Group: A group under normal conditions for comparison; e.g., fish in normal room temperature water.
   • Experimental Group: The group receiving the independent variable; e.g., fish in warmer water.

5. Results: Analyzing the data to determine if it supports or rejects the hypothesis.

   • Example: As water temperature increased, the average swimming speed of the fish also increased. This shows a clear trend: warmer water = faster swimming.

6. Conclusion: Modifying the hypothesis if needed and reporting the findings.

   • Example: The data supports the hypothesis. Fish swim faster in warmer water, possibly due to increased metabolic activity in higher temperatures. Suggested improvements: test more temperatures or use a larger sample of fish.

7. Repeat (optional): Repeating the experiment to increase reliability and sharing results with peers for review.

Key Terms

1. Independent Variable: The variable that is purposely changed in the experiment. It is what you are testing to see how it affects something else.

2. Dependent Variable: The variable that is observed or measured in the experiment. It depends on the independent variable.

3. Constants (Controlled variables): Parts of the experiment that stay the same for all groups. They ensure the test is fair by isolating the effect of the independent variable.

4. Experimental Group: The group that receives the independent variable-- the one you are testing.

5. Control Group: The group that does not receive the independent variable. Serves to help observe what would happen under normal conditions.

6. Data: The information collected during the experiment.

   • Quantitative: Numerical data (e.g., speed in cm/s).
   • Qualitative: Descriptive data (e.g., "the fish looked more active").

7. Placebo: A fake treatment that looks real but has no active ingredients, used in experiments to compare against the actual treatment. It helps scientists see if the real treatment works better than doing nothing.

8. Double Blind Study: An experiment where neither the participants nor the researchers know who is getting the real treatment or the placebo.

9. Isolating Factors: Ensuring that only one variable is changed in an experiment, while all other conditions stay the same to avoid confounding variables.

Overall Knowledge

Key areas to understand include:

1. The order of the 5 (or 7) steps in the scientific method.

2. The role of variables (independent, dependent, and constants) in an experiment.

3. The purpose and importance of placebos and double-blind studies in experiments to reduce bias and improve validity.

4. The distinction between a hypothesis and a theory; a hypothesis is a testable explanation for a specific phenomenon, while a theory is a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.

5. How all steps of the scientific method are interconnected and contribute to the process of scientific inquiry.