It's a totally different concept. Friom the documentation, SAP Information Steward User Guide, section 2.15.3.4 Functions:
is_data_dependent:
Indicates True when the value of the primary column determines the value of the dependent column. For example, if “X” is the primary column and “Y” is the dependent column, then “X --> Y” or “X determines Y”.
Also, one value of the primary column has only one value in the dependent column throughout the data set. In other words, if one value in the primary column has more than one value in the dependent column, it is not data dependent.
There can be multiple columns listed in the function for both the primary and dependent columns.
The results (True or False) passes or fails all records in the data set.
An example: X = CountryCode, Y=CountryName
If for all records where X ='NL', Y contains 'the Netherlands', then result is true.
If for some records with X='NL', Y contains 'the Netherlands', and for some others Y contains 'Holland' then result is false.