A random sample was taken of over 136 introductory textbooks (see Appendix B) published between 1885 and 1996, in order to record the names of, and frequency of occurrence of, the terms law and theory in these books. This appendix gives information from that survey and is offered as an empirical set of raw data, or data bank, for possible use by historians and researchers concerned with historiographic analyses of psychology; cf: J. E. Roeckelein (1996c), ‘‘Citation of Laws and Theories in Textbooks across 112 Years of Psychology, Psychological Reports, 79, 979–998.
Entries on the following laws and theories tables refer to percent of reference made by writers collectively within a given time period. For example, a ‘‘0’’ entry means that none (zero percent) of the writers in that time period made reference in their books to that given term; a ‘‘57’’ entry means that 57% of the writers in that time period made reference in their books to that given term; and so on.
There are over 800 laws and theories listed in this appendix; the total time period is broken down into five separate subperiods (columns).
Entries are based on the precise term that was used in a given textbook. Sometimes, there were synonymous terms for a single concept, and these were given only a single entry if both terms happened to be used in the same book. For example, ‘‘tetrachromatic theory’’ is synonymous with ‘‘opponent-process theory,’’ which is synonymous with ‘‘Hering’s color theory.’’ An attempt was made to record only single (‘‘presence versus absence’’) entries for any given term for any given textbook. Moreover, a name (such as Jung, Adler, etc.) may be mentioned in a book, but it’s entered here only if the term theory or law has been explicitly attached to it by the writer.
In addition to synonymous terms appearing on these lists, the designation ‘‘general’’ occurs in parenthesis after some of the terms. This refers to the use of the word theory in a general context or meaning (such as ‘‘learning theories’’) and is distinguished from specific usage (such as ‘‘Hull–Spence learning theory’’). Again, redundancy of usage was avoided in recording data from any given textbook, and the term law or theory had to be explicitly connected to the concept in order for it to serve as an acceptable datum entry.
Finally, it will be noticed that some terms are included under both the laws and the theories rubrics; this is because they appeared that way in the textbooks surveyed.