Day of week statistics
What it shows
The table of numbers behind the day-of-week chart: for each day n (how many days entered the mean), the mean change %, the 95% confidence interval, the share of up days and the quality badges. The same daily mean as the chart, in full numeric form.
How to read it
Start with the quality column: read a row without badges as a curiosity. Then check whether the confidence interval sits on one side of zero and whether n is meaningful. A historical tendency, not a forecast.
Parameters
- n (sample size)
- How many historical days back the group. A small n (the “low sample” badge) = a result too noisy to take seriously.
- Whiskers / 95% CI
- Whiskers are the 95% confidence interval of the mean: a realistic range for the true value. A narrow interval = a more confident reading.
- Positive reading: The whole interval on one side of zero: a clear tendency across the data window.
- Negative reading: Whiskers crossing zero: the interval contains 0, so it may just as well be noise.
- % up days
- What share of the group's days closed positive. Compare with the whole-window base rate (usually ~50%), not with zero.
- FDR-significant
- The green badge: the result passed the multiple-comparison correction (Benjamini–Hochberg). Without it, with ~30 tests per profile, a few “significant” results are pure chance.
- Stable over time (walk-forward)
- The stability badge: the effect keeps the same direction in both the earlier and the later half of the window. “Unstable” = the tendency may have already faded.