Field Notes: Measurement & Data

The Property That Was Counting Twice

Conversions looked strong for weeks - two properties, both live, both counting the same checkout.

Why We Stopped Trusting the Sample Size

A test was called a winner on day four - it wasn't the sample size that was the problem.

The Address We Removed

A stale address, precise coordinates, a fake 24-hour claim - removing beat correcting.

The Contract Nobody Signed

Three different bugs, one missing thing in common: a data contract.

The Tag Container Autopsy

What was double-firing, what was dead, and why.

The SCD Trap

A Type 2 dimension only wrong on the days something actually changed.

The Schema Drift Problem

Canonical tags, Open Graph, and JSON-LD quietly disagreeing across a dozen pages.

The Semantic Drift Problem

Active Users jumped with no schema or SQL change behind it.

What Businesses Get Wrong

What's usually missing from small business measurement, and what it costs.