Width of the interval: what it means and how to read it
In the report: CI Width — Upper − Lower.
How to read it
The narrower, the more precisely the slope is known.
In plain words
A teacher found that students who studied one hour more got 5 points more, with a range from about 2 to about 8 points. She wanted one number for how exactly she knows those 5 points. The width of the range, the distance from its bottom end to its top end, came out 5.6. Another class gave a range from about 4 to 6 points, a width of only about 2 points. Now she can answer: the narrower the range, the more exactly the points per hour are known. The second class gives her a much firmer number than the first one.
Example
The cell with CI Width is selected in each report; point at a label to see its note.
- — the sample data (50 rows) the examples use
- —
=STATS_BOOTSTRAP(Data!A1:T51, "y", "x1,x2", 2000, "pairs", 0.95)
Where you see it
STATS_BOOTSTRAP— Bootstrap confidence intervals for regression via resampling.
Related values
- Estimate within the interval — TRUE (1) when the slope of the data lies inside the interval.
- p-value — The probability of a result at least this extreme if there were no effect (if the null hypothesis held).
- Adjusted p of the pair — The p of the pair corrected for the number of comparisons by the posthoc method.
- Lower bound of the interval — The lower bound of the confidence interval, at the level in the label.
- Upper bound of the interval — The upper bound of the confidence interval, at the level in the label.
Get it in your sheet
One formula in a cell gives the whole report, Width of the interval included. ALS Stats is a free add-on for Google Sheets™.
Install ALS Stats from Google Workspace Marketplace (opens in a new tab)