This prevents later entries on that page. Use pen, not pencil, and if possible, use the same pen throughout the day. This helps to support the case that an entry was made all at the same time and not altered later. If there is need to correct an old data entry, you may return to a previous page, but the change must be easily identified as separate from the original and must be dated, initialed, and witnessed as described below. The preferable and simpler solution is to enter the correction on the current day's page, citing the earlier page and noting why the original record needed correction.
Notebooks represent months of work.
If for no other reason, they should be locked up at the end of the day in a fireproof cabinet. Graduate students or short-term workers should leave their original notebooks with their supervisor. They may take photocopies with them, however. A good research notebook is a diary, not a memoir, stresses Houser. It reports things as they happen, not as they are recalled.