Louis M. Gomez

The vocabulary problem in human-system communication

In almost all computer applications, users must enter correct words for the desired objects or actions. For success without extensive training, or in first-tries for new targets, the system must recognize terms that will be chosen spontaneously. We studied spontaneous word choice for objects in five application-related domains, and found the variability to be surprisingly large. In every case two people favored the same term with probability <0.20. Simulations show how this fundamental property of language limits the success of various design methodologies for vocabulary-driven interaction. For example, the popular approach in which access is via one designers favorite single word will result in 80-90 percent failure rates in many common situations. An optimal strategy, unlimited aliasing, is derived and shown to be capable of several-fold improvements.

SuperBook: an automatic tool for information exploration—hypertext?

The goals and methods of the text browser, SuperBook, are compared with those of hypertext systems in general. SuperBook, intended to provide improved access to text existing in electronic form, employs cognitive tools arising from human computer interaction research, such as full-text indexing, adaptive aliasing, and dynamic views of hierarchical information. Superbook automatically preprocesses on-line text written for paper publication, and produces a multi-window display, including a dynamic table of contents, pages of text, and a history of search words. Although SuperBook and hypertext share common goals of improved search and navigation, SuperBook is designed for accessing existing documents while most hypertext systems are better suited for authoring new information structures. Further studies are needed to evaluate the effectiveness of each of these kinds of systems.

Learning to use a text editor: some learner characteristics that predict success

Why do some people have much more difficulty than others in learning a computer-based skill? To answer this question, we observed first-time users of computers as they learned to use a computer text editor. In two experiments, older people had more trouble than younger people and those who scored low on a stanbdard test of Spatial Memory had greater difficulty than high scorers. These correlations were stable over several hours of practice and did not vary as a function of the type of terminal used or specific editing problems attempted. Correlations involving Age and Spatial Memory could not be explained by other characteristics such as amount of education, reasoning ability, or associative memory ability. Results like these that relate learning difficulty to specific characteristics of people ultimately may suggest ways to change computer interface design or training to accommodate a wider range of users.

All the Right Words: Finding What You Want as a Function of Richness of Indexing Vocabulary.

The implications of index‐word selection strategies for user success in interactive searching were investigated in two experiments. People were asked to find target information objects using a simple interactive keyword information retrieval system in which the number of referent terms assigned to each object was systematically varied. The results demonstrate that searcher success is markedly improved by greatly increasing the number of names per object.

Reference frames in mental rotation

Four experiments are reported that investigate whether images or reference frames are transformed during a mental rotation task. In all experiments a display of four identical letters (P1) was presented at either +90 degrees or -90 degrees from upright, and subjects had to decide whether the letters were normal or mirror-image reflections. A single letter (P2) was then presented 100 ms later in a variable orientation with the same task instructions. Reaction times to P2 were assessed to determine whether an image of P2 was rotated to upright or whether an internal reference frame was rotated into congruence with P2 from the orientation of P1. The results as a whole suggest that transformations of P2 can be initiated either relative to upright or relative to the orientation of P1. They further indicate that the probability of using each reference orientation can be changed by procedural variations. The findings are most parsimoniously interpreted as suggesting that mental rotation involves the transformation of reference frames rather than the transformation of template-like representations.

A Cognitive Analysis of Database Query Production

Two distinctly different methods of expressing database queries were compared to evaluate differences in their difficulty. One method was a standard database query language, SQL, while the second method only required subjects to be able to make use of tables representing sample databases. Clear differences emerged in subject performance. Regression techniques demonstrated an association between performance and a set of cognitive skills.

Networking for education: the resource access approach to learning

American education is on the verge of a revolution. The revolution is focused on involving students in real-world tasks and in practicing communities, both geographical and topical, where these tasks are done. This revolution is characterized by a new recognition of the social and community nature of learning and requires providing students and teachers with access to people, information, and computers that form the rich variety of existing and emerging education resources. We describe the manner in which current and next-generation communications technology support this approach and can provide the ubiquitous connectivity implied by this approach. We describe the key characteristics of the needed technological innovations.