A note on dual scaling of successive categories data

Three methods for dual scaling of successive categories data are formulated. They are mathematically equivalent, and provide an appropriate technique to determine stimulus values and category boundaries on a joint scale, a problem that Nishisato's method (1980a) failed to handle. This study was supported by the Natural Sciences and Engineering Research Council of Canada (Grant No. A7942) to S. Nishisato. Comments on the earlier draft from anonymous reviewers were most helpful and much appreciated.