Extensive measurement is called weak if the axioms allow two objects to have the same scale value without being indifferent with respect to the order. Necessary and/or sufficient conditions for such representations are given. The Archimedean and the non-Archimedean case are dealt with separately.

The Findlay-Walker model does not consider saccades generated by auditory targets or nontargets (distractors), or by bimodal stimulation. Empirical results suggest that the effects of auditory stimulation cannot easily be incorporated into the model, neither in the WHEN nor in the WHERE system. A two-stage model by Colonius and Arndt gives a quantitative account of the facilitative effects of auditory distractors on saccadic latencies toward visual targets.