Science Journal Best Practices

A science journal is the scientist's working memory. Every measurement, sketch, and stray idea goes in it — in real time, as it happens. Good journal habits make experiments repeatable, mistakes traceable, and conclusions trustworthy. Sloppy journals lose evidence forever.

Sections of a Journal Entry

1. Date — when the work was done, including time of day if it matters.
2. Question — the testable question being investigated that day.
3. Hypothesis — your prediction with a reason behind it.
4. Procedure — exact steps you followed, in order, with materials.
5. Observations — measurements and notes, recorded as they happen.
6. Conclusion — what the data shows, and what you plan to do next.

Best-Practice Habits

• Write in the journal during the experiment — never from memory afterward.
• Use pen, not pencil. Cross out mistakes with one line — do not erase.
• Record exact numbers and units (cm ≈ 0.4 in, mL ≈ 1/5 tsp, °C — 0°C = 32°F, seconds) — never "a lot" or "a bit".
• Label every diagram, table, and chart with a title and units.
• Note anything unexpected, even if it seems irrelevant — it might explain a result.

What Goes Where

• Materials list belongs in the Procedure section, before the steps.
• Raw measurements and tables belong in Observations, not Conclusion.
• Sketches belong next to the observation that describes them.
• New questions for next time belong at the end of the Conclusion.