Mode describes repetition rather than numerical center. It can be useful for discrete observations and recurring exact values, but a list is not guaranteed to have one unique mode. A calculator should state its convention because different tools sometimes report the first repeated value, every tied value or a misleading mode for an all-unique list.
All unique values mean no mode
In 2, 3, 4 and 5, every value occurs once. No value is more frequent than another, so SetStats reports “no mode.” Calling every value a mode would add no information and conflicts with the ordinary calculator convention. This result does not mean the list is invalid; it only means frequency does not identify a distinguished repeated value. Count and sorted preview make the convention easy to verify.
A unique maximum frequency gives one mode
For 1, 2, 2, 3 and 8, the value 2 occurs twice while every other value occurs once. The mode is therefore 2 with frequency 2. The magnitude of 2 is not what makes it the mode; only its count does. Adding another 8 would create a tie rather than letting SetStats choose whichever value appears first in the input.
Tied maximum frequencies produce multiple modes
The list 10, 2, 38, 23, 38, 23, 21 has two modes: 23 and 38, each with frequency 2. SetStats normalizes equivalent decimal spellings such as 2, 2.0 and +2.00 before counting, then sorts tied modes numerically. Decimal mode must still match the input. A decimal comma list uses spaces or semicolons between values so commas remain part of each number.