Observations and results
Did you find that some test squares had significantly decomposed after four to five weeks? Did some squares decompose more than others?
After being in the indoor composter for four to five weeks, some of the test squares should have clearly decomposed, although it depends on the exact products you tested and their composition. Very thin items (such as compostable food bags) may have decomposed more than thicker items (such as compostable eating utensils). Compostable bowls and deli food containers should have visibly decomposed some.
Nitrogen and water (from the green scraps) along with carbon (from the brown scraps) are the key ingredients that microorganisms (from the soil) need to make compost efficiently, which they do by breaking down what's in the compost, including the materials that comprise biodegradable and compostable products. One other important element is oxygen, which is introduced to the compost when it is "turned," or aerated, with a compost aerator or your hands. If a compost pile has these four components in the right ratios, it should efficiently turn scraps into compost.
When you are finished with your activity, you can mix your compost into the potting soil of houseplants or add it to the soil around plants in your garden. If you tested biodegradable products, however, the compost should not be used on plants that are grown for food, because biodegradable products may contain toxins that could be released into the compost and taken up by the plants.
More to explore
Composting Indoors, from Journey to Forever
Hot versus Cold Composting Instructions: What's the Difference?, from GrowingAnything.com
Mushroom Packaging—Innovation Nation, from the National Science Foundation
Disappearing Act: How Fast Do Different Biodegradable & Compostable Materials Decompose?, from Science Buddies