Assumption

Every method calculates with assumptions about the data, for example "each person belongs to exactly one group". If they don't fit, the result can be distorted.

Example: For the comparison of the phone groups, Statable checks: two separate groups, numeric values, enough people per group, unusual values.

Caution: A note is not a ban, but a reason to look more closely. Some assumptions no software can check, such as whether people answered independently of each other - that follows from how the data were collected.