Grouping Interval.Ratio data will change it to Ordinal data:

COLLAPSE

For example, in the survey, we asked for number of times you do grocery shopping per week?

The answers are 0, 1, 2, 3, or 4-7.

The interval/ratio data requires the interval between them is fixed or the same and meaningful. In this case, the last two answers, 3 and 4-7 are both meaningful but the interval is no longer the same. So it can only be Ordinal data.

It can be confused since the original data is indeed interval data (0,1,2,3,4,5,6, and 7), but the last one 4-7 is a grouping result. Thus, it changes the type of the data.

Do you have an example for this?