The MaxDiff is a long-established theory in mathematical psychology with very specific assumptions about how people make choices:[1] it assumes that respondents evaluate all possible pairs of items within the displayed set and choose the pair that reflects the maximum difference in preference or importance.
The formula, makes it clear that the effectiveness of this method, of assuming relations, drastically decreases as N grows bigger.
MaxDiff may involve multidimensional percepts, unlike most-least models that assume a unidimensional representation.
Indeed, MaxDiff might not be considered an attractive model on psychological and intuitive grounds: as the number of items increases, the number of possible pairs increases in a multiplicative fashion: n items produces n(n-1) pairs (where best-worst order matters).
Early work did use the term MaxDiff to refer to BWS, but with Marley's return to the field,[6] correct academic terminology has been disseminated in some parts of the world.