The notebook proves when things were done. This is why it is signed and dated in ink. When finishing a project it is easier to write the report when the observations are already written down once. A long time ago there were no tape recorders, laptop computers, or palm pilots. The lab book was all they had.
Some scientists now use more modern forms of the notebook.
Often good ideas come when you are doing something else - writing the thought down made sure it was not forgotten later. Some scientists are forgetful. Because a lab notebook is so important we are asking that all students try to keep some form of a lab notebook for their science expo project. Writing down observations is an important part of the scientific method. If you have a lot of extra pages don't worry - you can use it again next year andthe following year.