Mid-semester, stop adding entries for one sitting and write one that looks backwards.
Do this
- Re-read Your First Entry, including the sentence about how you think chemistry knows things.
- Find an early piece of work and a recent one on the same skill — two conclusions, two sets of limitations, two attempts to say what your numbers are worth.
- Put them side by side and name three specific differences. Quote yourself in both directions.
Same skill is the hard part. A first bond-type lab and a titration are different jobs, and comparing them shows nothing except that the titration came later. Comparing two conclusions — the paragraph where you say what you found and how much you trust it — is a fair comparison, because you wrote that paragraph both times.
Not this
“I have improved a lot and learned many things. My labs are much better than they were at the start and I understand the mole now.”
Nothing in that paragraph could be checked, argued with, or shown to be wrong. A claim nobody could contradict is not evidence of growth — it is a sentence about wanting to have grown.
This
My first conclusion, from Testing for Bond Type, was: “Sample C was ionic because it conducted.” One sentence, no numbers, and “conducted” is doing all the work — I did not say what the reading was, what the blank was, or how big a reading has to be before it counts.
My conclusion from the precipitation lab says: “We calculated that 1.42 g of calcium carbonate should form from the limiting reagent, and recovered 1.31 g, a yield of 92%. Weighing by difference on a balance that reads to 0.01 g puts about ±0.02 g on the recovered mass, so the yield is 92% give or take roughly 2 — meaning 92% and 94% are the same result and 92% and 82% are not. Precipitate left on the filter paper and in the beaker can only lower the recovered mass, so 92% is a floor rather than an estimate that could err either way.”
Three differences. The second one gives numbers with units instead of a verb. It states how well the number is known, so a reader can tell which comparisons the data can support. And it says which direction the main limitation pushed, which the first one could not have done because it had no direction in it to push.
The change in my head: I used to think the conclusion was where you announce the result. I now think it is where you say what the result is worth, and those turn out to be different paragraphs.
What I am reading for
That last line. Three differences in the work, and then one sentence about what changed in your thinking to produce them. The second is worth more than the first, and it is also the part people leave out.
A useful prompt if you are stuck
What do you now do automatically that you had to be told to do in the first month? Writing the units before the number. Checking a difference against the instrument’s resolution before calling it a difference. Recording the raw reading as well as the answer. Automatic is exactly the evidence — you stopped noticing you were doing it.
Related: Mistakes Are Data, and the closing entry in Final Reflection.