Whereas Otlet and Kaiser were in substantial agreement on both thedesirability of information analysis and its technological implementation inthe form of the card system, they parted company on the question of howindex files were to be organized. Both men favored organizing informationunits by subject, but differed as to the type of KO framework that shouldgovern file sequence: Otlet favored filing according to the classificatory orderof the UDC, whereas Kaiser favored filing according to the alphabeticalorder of the terms used to denote subjects
Compare the various organizational structures of Otlet, Kaiser, and Luhmann.
Seemingly their structures were dictated by the number of users and to some extent the memory of those users with respect to where to find various things.
Otlet as a multi-user system with no single control mechanism or person, other than the decimal organizing standard (in his case a preference for UDC), was easily flexible for larger groups. Kaiser's system was generally designed, built and managed by one person but intended for use by potentially larger numbers of people. He also advised a conservative number of indexing levels geared toward particular use-cases (that is a limited number of heading types or columns/rows from a database perspective.) Finally, Luhmann's was designed and built for use by a single person who would have a more intimate memory of a more idiosyncratic system.