What to ask your agency about data quality

The advice here is unglamorous, which is probably why it gets skipped. If you are briefing an agency or a freelancer on data quality, these questions are worth asking early.

Most data problems are ownership problems that turned into technical ones. It is the sort of thing that looks like polish right up until it costs you an enquiry.

Questions worth asking

• Who will actually do this work, and have they done it before?
• How will we know afterwards whether it worked?
• What happens if it needs changing in a year?
• What are you assuming that we have not confirmed?

What a good answer sounds like

Bad data spreads faster than anyone corrects it. In practice this is a scheduling problem more than a technical one. If it only works because one person remembers to do something, it does not work yet.

Someone must own each dataset or nobody does. Where this goes wrong is almost never a lack of knowledge. The practical test is whether someone new to the project could tell, in a minute, that it had been handled.

In practice

Numbers get quoted in meetings long after anyone remembers how they were calculated. Three things worth confirming about data quality before you move on:

• Someone can say what the current setup is without going to look
• Someone must own each dataset or nobody does — and you know whether that is true here
• There is a way to tell whether the last change to this helped

Pick the one that would hurt most if it failed, and start there.