Scientists try to understand the world around us by making careful observations. These observations often present problems. In order to solve these problems, scientists sometimes use a scientific method.

A scientific method is an orderly process that usually includes a series of steps similar to these:
1. Determine the problem. State what you want to find out.

2. Make a hypothesis. State the prediction that you want to test.

3. Test the hypothesis. State what steps you will take to design an experiment to test your hypothesis. Make observations. Record what happened during your experiment.

4. Analyze the results. Explain any patterns you see. Organize your observations and data into a usable form.

5. Draw conclusions. Describe what your observations and data indicate about your hypothesis. Decide whether or not your hypothesis is supported. If not, determine why your hypothesis is not supported and propose a new hypothesis.

In this Virtual Lab you will use a scientific method to determine how to create the most efficient compost pile.

Compost is decomposed matter that is used as fertilizer or as mulch (material put around plants to help them retain water). Compost is made by combining four basic ingredients: green materials, such as grass clippings, green leaves, and vegetable and fruit scraps; brown materials such as dried grass and leaves, twigs, straw, and sawdust; air; and water. In addition to being good for plants, compost is good for the environment because it makes use of materials that otherwise would go to waste.

Objectives:

• Apply a variety of strategies in order to solve a science problem.
• Identify factors that affect the efficiency of a compost pile.

Procedure:

Use your Journal to record each step of the procedure.

1. Determine the problem: Consider the four ingredients necessary to make compost and state a problem about making an efficient compost pile.

2. Make a hypothesis: Make a testable prediction about how the efficiency of a compost pile would be affected by varying the ratio of green to brown material, the amount of water added, and the number of times a compost pile is turned (to supply oxygen).

3. Test your hypothesis: Click and drag the Brown to Green Balance bar, the Water Concentration bar, and the Number of Turns bar to the position you want to test. Click the Calendar. Click the Table button and record the combinations you tested and the resulting Efficiency Meter reading.

4. Click the Reset button and test other combinations in the same way. Record your results in the Table.

5. Analyze your data: Use the Table to analyze your data about the efficiency of the compost pile.

6. Draw a conclusion: Draw a conclusion about what combination of factors produces compost most efficiently.