It is curious but there is widespread misuse of floating-point types to represent monetary amounts in introductory programming classes. This is evident from a survey of popular CS1 textbooks. It is instructive to examine how dollars and cents and other currency values are represented in actual practice and how we can utilize those techniques in computer science education, for both the sake of correctness and to illustrate important general principles. Furthermore, it is particularly interesting to review the history of CS education and determine how this situation came to pass. The interplay between technology, academic cultures and institutional development turns out to be quite significant.

A new variation of high order multiway tree structures, the P-tree is presented. P-trees have average access costs that are significantly better than those of B-trees and are no worse (and often better) in storage utilization. Unlike compact B-trees, they can be maintained dynamically, and unlike dense multiway trees and B-trees, their associated insertion algorithm, which is also presented, is cheap and involves (at most) a very localized rearrangement of keys.

It is well-known that the B-tree data structure yields excellent worst-case search costs and for that reason is widely employed in the organization of external files and in the implementation of data bases. In this paper, we examine general B-trees empirically and compare them with a less restrictive structure, the general multiway tree, and a more restrictive structure, the compact B-tree. We compare search costs, insertion costs, and space costs of these three structures for both small and large orders and indicate their relative utility for large and small data sets. Although there are cases when general multiway trees are more effective than B-trees, this is not the case for most practical situations. Compact B-trees are also shown to degrade rapidly in the presence of insertions and are therefore only useful for static data sets.

Two sets of algorithms for searching and dynamic reorganization of linear lists are presented. Each set forms a spectrum, with the well-known move-to-front and transposition algorithms at the extrema. A linear ordering on the stationary expected search cost of the algorithms in each of the two spectra is established over a restricted set of probability distributions.

The paper describes a computer system to determine salary costs in a work force which contains different salary levels and in which employees are being promoted to higher levels. The system is based on a mathematical model of employee promotional behavior which is described in the paper. The system was used in recent contract negotiations to estimate labor costs for proposed contracts. Experience with the system is described and further extentions of the system are proposed.

In this paper it is shown how the topic of BASED storage in PL/I can be used to illustrate a wide variety of concepts in intermediate level courses in data structures and programming languages. Because most instructors introduce the topic only from the point of view of a linked list, the true meaning of BASED storage and POINTERs is lost in the maze of practical problems which these features can be used to solve. Because BASED storage allows the programmer close access to physical storage, an understanding of these features goes a long way toward clarifying the behind the scenes actions involved in implementing and using data structures in high level languages.

Program efficiency is usually considered from the point of view of optimizing code. Selecting a proper data structure can have a remarkable effect on the efficiency of the final program. In this paper it is shown how one problem can be solved in several ways using several different data structures. The efficiency of the programs depend on the data structures selected.