Using Access to improve data integrity - Top 5 tips

When I see bad data in a database, there are several things you need to look at to improve the outcomes of your reports.  In general this is all going to fall under GIGO:  Garbage IN, Garbage OUT.  Cliche, but TRUE!  Here are my top 5 tips to help control your data quality:

1. Watch out for NULLS, which tend to break reports and formulas.  Use NZ to plan for bad data or nulls.  Example:  nz([Income],"N/A") will produce a result of N/A when there is no Income value.
2. Put threshold rules on key fields.  Example: If you have a date of birth field, add a rule for <date().  This ensure people do not accidentally enter 2107 as a year (I see this all the time).
3. Use conditional formatting.  Create conditional format rules that change the field color and font to highlight deviations which are out of our normal ranges.  I like to build formula based rules on number fields where I can use something like +/- 10% as my test.  You have to first understand what normal should look like before making these types of rules though.
4. Set critical fields to not allow Nulls
5. Create useful ControlTip  on the Other Properties tab to better inform a user.  This will display on the screen when the mouse hovers over the field.