Intercept: what it means and how to read it
In the report: Intercept — The constant of the model: the prediction when every predictor is 0.
How to read it
Rarely interpreted — a predictor value of 0 is often outside the data (age 0). It is needed to compute predictions.
In plain words
A teacher guessed scores from study hours and got a line: 20 points, plus 5 points for every hour. She wondered what the 20 means. The intercept is that 20: the guessed score for a student who studied 0 hours. She rarely reads anything into it, since 0 hours may never happen in her class, just as age 0 would never come up in a class of teenagers. But the add-on needs it to make guesses. For a student who studied 3 hours, she gets 20 plus 15, which is 35.
Example
The cell with Intercept 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) - — two steps; pass is coded 0 and 1
=STATS_LOGISTIC(Data!A1:T51, "pass", "x1,x2|x", 0, 50, 1e-8) - — 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_LOGISTIC— Binary logistic regression with optional ridge regularization (lambda >= 0).STATS_ANALYZE— Runs several analyses on one range and returns one report.
Related values
- Coefficient B — The coefficient of the predictor.
- Standard error of B — How much B would vary from sample to sample.
- Standard error of the estimate — The typical size of a residual: how far the observed Y is from the predicted one, in the units of Y.
- Sample size — The rows used: only rows where Y and every predictor of every step are filled (listwise), the same rows for all steps.
- 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.
Get it in your sheet
One formula in a cell gives the whole report, Intercept included. ALS Stats is a free add-on for Google Sheets™.
Install ALS Stats from Google Workspace Marketplace (opens in a new tab)