Correct Response: C. Dating and recording all procedures, events, and original data in ink to prevent erasures is important for protection and retention of all recorded information. Reorganizing the notebook by cleaning up data, notes, and records before each new lab (A) is not considered a good practice. Organization of the notebook should be accomplished prior to the lab. All notes should be written directly into the notebook in ink, and all data should be kept, not “cleaned up.” Mistakes should be corrected by crossing out the mistake and entering the correction next to the mistake. Rounding all data values to two significant figures before recording (B) would be arbitrary and is incorrect. Rounding of data should be based on the level of precision of the measurements being recorded. Keeping a separate notebook in which to record calculations and sketches (D) is incorrect, because all calculations and sketches should be entered directly into the laboratory notebook.