Lab notebook entry

A lab notebook is the record of what was actually done, not what the protocol said to do. Its first job is reproducibility: someone else (or the same person in six months) should be able to repeat the work and understand why a result came out the way it did. Its second job is honesty: the observation as seen, written down at the time, before anyone knows which result is wanted.

So the entry keeps a few hard lines. Raw observations stay raw. Deviations from the protocol are written down, because they explain most surprises later. Interpretation lives in its own section, apart from the data.

When to use it

• After a bench session, from scribbled notes, a voice memo, or photos of a paper notebook.
• A student writing up a teaching lab, or a researcher keeping an ELN.
• Logging a failed run, which matters as much as a good one.