We're organizing people into age buckets. For example: 0-20 yrs, 20-40yrs, 40-60yrs...
I'm struggling with how to best label the age buckets, there are two options:
(A) Don't repeat the values, so: 0-19, 20-39, 40-59...
The problem is, where does someone who is 19.5yrs go? The first or second bucket?
(B) Repeat the values, so: 0-20, 20-40, 40-60...
The problem is, in which bucket does someone who is 20yrs old go? The first or second bucket?
(C) Another option is to be very explicit and show the following: '0 to less than 20', '20 to less than 40', '40 to less than 60'...
The problem is that this is very long, clutters the UI, and doesn't fit in our chart axis
We're also doing a similar bucketing for company tenure, so 0-1yrs, 1-2yrs, 2-3yrs, etc - we want to ensure we're consistent across the board.
The user persona is non-technical users with no formal mathematical training, hence using set theory symbols such as [1-2) is not an option.
Any opinions? Suggestions?
Update
I also agree that option A is best. However, another big point of confusing is when setting a filter of 'less than'. For example, saying filter on 'less than 3yrs' means you will only see the age buckets for <1yr, 1yr, 2-3yrs. However, the 2-3yrs bucket value will be different than the one you see without the filter - sans-filter the 2-3yrs bucket shows 2-3.999yrs and with the filter it will be reduced to only showing 2-2.999yrs
What do you guys think is the best way to handle this?