There is no formula as to how long a science fair project should take to complete, and the higher the grade, the higher level of rigor, and thus the more time that should be spent. Science has no right or wrong answers so experiments are often modified and repeated before results are achieved. Ideally, an experiment should be replicated. An invention takes time to build, optimize, test, and refine. A study requires time to research, collate, and interpret.
A science fair project should reflect a balance between time spent and the value of the project in terms of student learning and/or assessment. Often the most difficult and time consuming portion is deciding on a topic, and it may be advantageous to inform students about the intention of doing a science fair as early as possible.
On the day of the fair, projects can be arranged around the classroom for judges to view. Realistically, for a thorough examination of the project, judges should plan to spend 15 minutes at a project. The student’s oral presentation should take five minutes. Judges questions should take five minutes. Finally, a judge should have five minutes to fill out a judging rubric. Generally, this means one judge can assess three to four projects in one hour. For fairs that involve more than one classroom, a larger space, such as a cafeteria or gymnasium, might be needed for a large portion of the day.
Space requirements vary with the number of projects. Students may work alone or in pairs. A typical project backboard will be about 1.2 meters wide and 0.8 meters deep, and there must be enough room for the student(s) and judges to stand in front of the projects