A Range of Errors

Ah… data values within a range. So many possibilities for fun. Ran into one of those today while reviewing a potential work item being proposed. As presented:


Add "Length of Incarceration" range

Select from a list
* Less than 1 year
* 1-3 years
* 3-5 years
* 5-10 years
* 10-20 years
* More than 20 years

Spot the problem? What happens if the length of incarceration was 1, 3, 5, or 10 years? Which of the two ranges that include these values should be chosen?

Presumably we’re grouping this data into ranges for reporting purposes.

At what point does it become statistically significant that given a situation where an offender spent 5 years incarcerated, Elizabeth always chooses 3-5 years, Ross always chooses 5-10 years, and Eduardo sometimes chooses one range and sometimes chooses another?

In any system with user-entered data, GIGO can apply, but let’s help the users by designing a system which makes it harder to input garbage.