Sample size: what it means and how to read it
In the report: Sample size — The rows used: only rows where Y and every predictor of every step are filled (listwise), the same rows for all steps.
How to read it
Compare it with your sample: every row with a gap in any of the columns is dropped.
In plain words
A teacher had 40 students, but 8 of them left sleep hours empty. She wanted to know how many students her result really rests on. She looked at the sample size and found 32. Now she knows that every student with a gap in any of the columns is left out, and when the add-on works in several steps, the same 32 students are used in every step. She compares it with her 40 and can tell the reader that 8 were dropped. If most had been dropped, she would be careful with the result.
Example
The cell with Sample size is selected in each report; point at a label to see its note.
- — the sample data (50 rows) the examples use
- —
=STATS_LINEAR(Data!A1:T51, "y", "x1,x2", 0) - — old syntax: regression steps, one-sample test against 15
=STATS_ANALYZE(Data!A1:T51, "linear(y|x1|x2) oneSample(x1|15)")
Where you see it
STATS_LINEAR— Multiple linear regression (OLS) with hierarchical steps separated by | and interactions a*b.STATS_ANALYZE— Runs several analyses on one range and returns one report.
Related values
- Variance inflation factor — How much the variance of B grows because the predictor is correlated with the other predictors. Empty when lambda is above 0.
- Covariance — How the two columns vary together, in the product of their units: positive — they rise together, negative — one rises as the other falls.
- Regression slope — The least-squares slope of this column on the column xCol, on the rows where both are numbers; empty with fewer than 2 rows or without spread of X.
- Resampling method — pairs — whole rows are drawn with replacement; residual — the fitted values plus residuals drawn with replacement.
- Slope — The least-squares coefficient B of the last predictor of the step, the other predictors of the model held fixed — computed on the data as they are.
Get it in your sheet
One formula in a cell gives the whole report, Sample size included. ALS Stats is a free add-on for Google Sheets™.
Install ALS Stats from Google Workspace Marketplace (opens in a new tab)