Science fair projects involving laundry detergent often involve the effectiveness of a particular type of detergent when compared to another. Typical comparisons involve brand names, price, enzyme-containing detergents versus those that do not contain enzymes, or homemade detergent versus commercial products. When designing such projects, the student should take steps to ensure other variables do not influence his results.
Once the student decides the types of detergent he wants to compare, he should create a stain for comparison. Using two similar pieces of cloth, he applies the same amount of staining material to each. Powdered drink mix is one common stain that is a challenge for many detergents. Once he has stained the fabric, he treats both pieces in the same manner, with the exception of the detergent he uses for cleaning. He uses the same machine for washing both pieces. He uses the manufacturer's recommended amount of detergent, and he tries to ensure he washes both pieces in water of the same temperature. After drying the fabric, the student compares the results after washing to a similar piece of cloth that he did not stain. Some students use a microscope or magnifying glass for the comparison.
Students display their projects on a project board. The board should include the original hypothesis, a brief explanation of the experiment, a display of the stained fabric after washing, and the student's conclusions.