An abstract is an abbreviated version of your science fair project final report. For most science fairs it is limited to a maximum of 250 words (check the rules for your competition). The science fair project abstract appears at the beginning of the report as well as on your display board.Almost all scientists and engineers agree that an abstract should have the following five pieces: 1  Introduction. 2  This is where you describe the purpose for doing your science fair project or invention.he science fair project abstract appears at the beginning of the report as well as on your display board. Almost all scientists and engineers agree that an abstract should have the following five pieces: 1  Introduction.