Unit 06 · Uncertainty, Error & Honesty
No measurement is ever perfect, and that is not a problem to hide — it is the truth to report. This unit teaches a student to tell a wobbly stopwatch thumb (random error) from a ruler that starts at the wrong mark (systematic error), to run a trial more than once and report the spread, and to state a measurement together with its doubt. When a fizz tablet dissolves in 40 to 46 seconds, or one paper airplane flies strangely short, the honest scientist keeps that odd point and says so. Mastery means you report what really happened — even when the result disproves your hypothesis.
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Sources of error | Blames “human error” for everything, or can’t say where a measurement might go wrong. | Names a source of error but can’t tell whether it scatters results randomly or pushes them all one way. | Distinguishes random error (a wobbly stopwatch thumb) from systematic error (a ruler that starts at 1 cm), and names each. |
| Repeat trials & spread | Measures once and treats that single number as the truth. | Repeats the trial but ignores how much the results differ from each other. | Runs several trials and reports the spread: “the fizz tablet dissolved in 40 to 46 seconds across five tries.” |
| Reporting uncertainty | Reports a lone number as if it were exact. | Admits the measurement isn’t perfect but can’t attach a range to it. | States the measurement with its doubt: “about 12.5 cm, give or take half a centimeter, from how hard the ruler was to read.” |
| Anomalies & outliers | Quietly erases a point that doesn’t fit, or never notices it. | Spots an odd point but drops it with no reason, or keeps it without a second look. | Flags the outlier honestly, keeps it in the record, and says what might have caused it — never deletes a “bad” point silently. |
| Intellectual honesty | Changes numbers or the hypothesis to make the results “come out right.” | Reports the real result but calls the experiment a failure because it disproved the guess. | Reports a result that disproves the hypothesis as a real finding: “the paper airplane didn’t fly farther — that’s a true answer, not a mistake.” |
| Integration (cross-domain) | Treats honesty-with-data as isolated; makes no connection to the year’s anchor. | Mentions Semmelweis but can’t say what honesty had to do with his data. | Connects honest reporting to Semmelweis — who let uncomfortable death-rate data stand even when colleagues resented it — across History · Reading · Statistics, and defends why it mattered. |
“I timed the tablet five times and got 40 to 46 seconds, so I’d report about 43, give or take three. One trial came in at 61 — that’s an outlier, but I’m keeping it in and noting I may have started the timer late. And my hypothesis was wrong: the warm water didn’t win by much. That’s still a real result.”
“I timed it once: 43 seconds. One try was way off so I just crossed it out. My guess was wrong, so the experiment kind of failed.”
You demonstrate this unit through watched measurement tasks — running repeat trials, reporting a result with its uncertainty, and deciding aloud what to do with an odd point — plus short oral checks where you explain your reasoning. Not a multiple-choice test. A criterion counts as mastered only when a guide can watch you handle real, messy data honestly: keep the outliers, report the doubt, and stand behind a result even when it disproves your hypothesis. Mastery is demonstrated, not awarded.
A 5-page clipboard packet — unit overview, key terms, the mastery rubric, anchor examples, and a score sheet you can print and grade against.