Changes and data contracts
Silent change
A new enrolment status reaches the data overnight, and each side of the university saw only half of the change.
Topics › Data quality and change › When things go wrong
Too good to be true: what a test on a number is for
Applications jump 38% overnight, and a committee is about to plan 600 extra places. Every row check passes. What should a test on the total do?
Builds on The Inner Life of Data · Refining with dbt and Gold
Watch the film
Press Play, or pick a chapter. Turn on Pause and think to stop for one question at the end of chapters.
Download the videoCaption filesRead the script
How to read the film
Light is data, as in The Inner Life of Data. Each person's outline shows their side: cyan for technical, gold for business. The gauge beside a number is a test on it: amber is a warning, which lets the data through; red is an error, which stops the build. Lilac is the admissions system. The university, people and numbers are fictional. The narration is a synthetic voice.
English captions are on by default; turn them off with Captions. The video you download has none on the picture: play it with its caption file, in English or Spanish.
Where next?
You've seen what a test on a number is for. Now try it yourself.
Think it through
The four Pause and think questions, for a class or a team. Open one to see the answer.
Go further
Start here
The Inner Life of Data
Follow one enrolment from a tap on a phone to a decision, through Databricks and dbt.