The Scientific Method! A step by step guide for the rest of the year.

The Scientific Method involves a series of steps that are used to investigate a natural occurrence.

Knowing and following these steps are crucial to both this class and the TAKS test!

Problem/Question Observation/Research Formulate a Hypothesis Experiment Collect and Analyze Results Conclusion Communicate the Results

Steps of the Scientific Method Problem/Question 1. Identify a Problem/Question: Must be testable !!!!!! Make observations and conduct research 2. Make observations and conduct research: has anyone else looked at this problem?

Steps of the Scientific Method Formulate a Hypothesis 3. Formulate a Hypothesis: Predict a possible answer to the problem or question. Experiment 4. Experiment: Develop and follow a procedure. Include a detailed materials list. The outcome must be measurable (quantifiable).

Steps of the Scientific Method 5. C CC Collect and Analyze Results: Modify the procedure if needed. Confirm the results by retesting. 6. C CC Conclusion: Include a statement that accepts or rejects the hypothesis. Make recommendations for further study and possible improvements to the procedure.

Communicate the Results 7. Communicate the Results: Be prepared to present the project to an audience. Expect questions from the audience.

The example Lets take a basic problem and analyze it scientifically.

Problem/Question Belton lake fish are dying in large numbers. Coincidentally a new Industrial plant has opened and has been discharging waste into the lake.

Observation/Research We would research the type of waste being discharged from the factory. Have any similar cases been reported in the past, etc, etc….

Formulate a Hypothesis Textbook definition: The hypothesis is an educated guess about the relationship between the independent and dependent variables.

Formulate a Hypothesis This can be tricky! Your hypothesis must be simple, direct, and testable. =

We will often use an experimental design template to keep track of the details. Design your experiment

Do you know the difference between the independent and dependent variables?

Independent Variable The independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter. Example: We will add 5 mL, 10 mL, or 20 mL of toxic waste.

Dependent Variable The dependent, or responding variable, is the factor that may change as a result of changes made in the independent variable. Example: the number of dead fish.

Other Details of the Experiment A clear procedure so that someone can replicate your experiment. A list of required materials so they use the correct equipment.

Other Details of the Experiment In a scientific experiment, the control is the group that serves as the standard of comparison. The control group usually is exactly the same as the test groups but the Independent variable is absent or set to “zero” No toxic sludge in the control!

Control Group The control group is exposed to the same conditions as the experimental group, except for the variable being tested. All experiments should have a control group.

Trials Trials refer to replicate groups that are exposed to the same conditions. This will eliminate “freak” outcomes.

Constants Remember! In a valid experiment the only things that should change from trial to trial are the independent and dependent variables!

Can you think of some constants for this experiment?

Collect and Analyze Results Data should be clear and organized. A Data table should be drawn BEFORE the experiment is conducted.

Toxic waste and fish mortality Amt. of waste 123Averagedeaths 0 mL mL mL mL Number of dead fish Trials Control group

Can you accept or reject your hypothesis?

Communicate the Results You now have hard data that supports your hypothesis. This is hard to argue against!