When a scientist starts a new topic, she must read up on what other scientists have already discovered. Look for non-fiction books that give you factual information about potatoes and potato roots. Based on your research, formulate questions. Some examples of questions you might ask are: How do potatoes grow roots? What part of the potato can grow roots? Is there a limit to the number of roots that a single potato can develop? Under what conditions will potatoes grow best?
Select one testable question and make an educated guess based on research facts, or hypothesis as to the results. For example, if you choose "What part of the potato can grow roots?" as the question, you might hypothesize that every part of the potato grows roots.
Design a procedure that tests for the variables in the question to prove or disprove your hypothesis. For the purposes of testing root growth in different potato parts, you would cut the potato into eight equal slices. Label the slices A to H. Place them in identical growing conditions. Leave them until you notice the eyes starting to sprout and the roots develop. Count the roots on each piece and compare with the hypothesis.
Write a paragraph each on the research summary, the question, the hypothesis, the testing procedure and the results. Include graphs, charts and pictures of the whole process. Arrange the parts of the science project in chronological order on a science fair display board for an organized and visually appealing presentation.