← All categories

Category

Data Quality

Recognize the failures that make tidy, persuasive data lead to the wrong decision.

Start with completeness: missing data does not always look broken.

Reading guide

What questions are we asking?

Data quality starts with “good enough for which decision?” A table can contain valid-looking values and still omit a whole device, period, or customer group. Start with completeness and learn to distinguish a missing observation from an observed zero.

  • Is the data complete for this question, at this grain and over this period?
  • Are missing records being interpreted as zero activity?
  • Could a tracking change explain the apparent business change?

A suggested reading path

  1. The 6 Dimensions of Data Quality — Completeness

    Read the published opening essay: coverage gaps, MCAR/MAR/MNAR, and the business consequences of missing data.

Try it at work

Before filling nulls, make a coverage table by date and by the segment your decision depends on. Compare it with an independent source and investigate missing slices. The six-dimension series is in progress; completeness is the first published part.

Series

Data Quality Is Six Different Ways to Make a Bad Decision

A series in progress on six dimensions of data quality, written in business terms. Start with the published essay on completeness.

Explore the series →

All essays in this category