| Editorial | | BIB | 1-2 | |
| Tom Stewart | |||
| Context and Self-Selection Effects in Name Learning | | BIBA | 3-17 | |
| W. P. Jones; T. K. Landauer | |||
| In laboratory learning tasks, people's spontaneously chosen responses to stimuli have been found to be more memorable than equivalent responses chosen by someone else. In a computing situation, this suggests that it might be desirable to let new users select their own names for commands. However, it can also be argued that new users cannot name a command effectively, because they lack sufficient knowledge concerning the overall structure of the command set and its referents. Since existing psychological research has little to say about the relationship between contextual or structural knowledge and selection mode (self versus other), these factors were crossed in an experiment where subjects learned names for different objects (personnel data categories and descriptions of text-edit operations). In subsequent recall tests, beneficial effects were observed both for context knowledge and for the self-selection of names. Several interactions involving these factors were also significant. For personnel data categories, the context manipulation had no effect on performance when subjects were allowed to select their own names, but helped if they had to learn assignments made by others. For the less familiar text-editing descriptions, context information helped performance in general and considerably enhanced the benefits of self-selection. | |||
| Human Information-Processing Strategies and Style | | BIBA | 19-29 | |
| Ivan T. Robertson | |||
| The interactions that take place between the human and artificial aspects of information-technology systems are basically cognitive. Research in cognitive psychology conducted over the past 30 years or so has demonstrated that people exhibit significant individual differences in the information-processing strategies that they adopt during problem solving and other decision making activities. The different strategies that have been observed are outlined and some ideas concerning the theoretical bases of these strategies are discussed together with the implications that such human characteristics have for the operation and design of man-machine systems. | |||
| Adaptive Personalized Interfaces -- A Question of Viability | | BIBA | 31-45 | |
| Saul Greenberg; Ian H. Witten | |||
| It is widely accepted that interfaces between computers and users should
differ to accommodate individual, or group, needs. One method of
'personalizing' an interface is to have the system form a limited model of the
user and employ it to fashion the dialogue to his needs. Unfortunately, little
is known about the effect of adaptation on the man-machine interface. Although
obvious advantages accrue from 'personalized' interfaces, there are also
obvious disadvantages to presenting users with a changing, adapting and perhaps
apparently inconsistent interface. The goal of this work is to determine the
viability of an adaptive interface through a human-factor pilot study of a
simple, specially designed, interactive computer system.
The system uses menu-driven selection to retrieve entries from a large ordered telephone directory. This simple task has several advantages: it is a realistic application area for interactive computers; plausible adaptive modelling methods exist and have been studied theoretically; and previous work has determined the best way to display the menus to users. The results of this empirical study support the use of adaptive user modelling. In the (admittedly highly constrained) example system, a computer interface can indeed adapt successfully to every user. Although it does not necessarily generalize to other user interfaces, the result supplies evidence to refute published objections to adaptive user modelling in general. | |||
| Introducing CAD Systems. Problems and the Role of User-Developer Communication in Their Solution | | BIBA | 47-61 | |
| Wilhelm Schaffitzel; Uwe Kersten | |||
| Every introduction process of a CAD system calls, at least potentially, for user-developer communication (UDC), since CAD systems always require adaptations and completion of the software to meet the specific requirements of a company. Furthermore, there is a principal demand for the redesign of the organization in which CAD is to operate. On the other hand, quite a few methods and procedures of UDC have been developed and tested, though not in the field of CAD. An empirical study of CAD applications in the West German mechanical engineering industry shows that the typical conditions under which CAD is introduced and the problems which arise in connection with the introduction in practice call for methodical guidance of the process and particularly for increased UDC. At the same time managers, developers and users are not aware of the methods of UDC and their potential. The question whether UDC would, in fact, have positive effects on the introduction process remains unanswered. As a conclusion some principal conditions are tentatively stated which must be fulfilled before methods and procedures of UDC can gain practical importance. It is suggested that with respect to the introduction of CAD systems UDC should not, in practice, be restricted to the process of software development, but should much rather comprise the process of organization development as well. | |||
| Identifying Causes of Failure: A Case Study in Computerized Stock Control | | BIBA | 63-72 | |
| Christopher J. Rowe | |||
| This case study considers the introduction of a computerized stock control system at a chocolate factory that is part of a large foods group. It focuses upon the problems faced by management and argues that such installations involve not merely quantifiable, technological issues, but also, qualitative, human concerns which management are apt to ignore. Management searched for a single causal factor -- the reason why the computer was causing problems -- which was to detract from the multiplicity of factors that were interacting and compounding to create system malfunctioning. | |||
| "Human Aspects of Office Automation," edited by B. G. F. Cohen | | BIB | 73-74 | |
| Ken Eason | |||
| Ergodesign 84, Montreux, 6-9 November 1984 | | BIB | 75-76 | |
| E. Grandjean | |||
| Editorial | | BIB | 79-80 | |
| Tom Stewart | |||
| Learning a Menu Selection Tree: Training Methods Compared | | BIBA | 81-91 | |
| Diana Parton; Keith Huffman; Patty Pridgen; Kent Norman; Ben Shneiderman | |||
| Menu selection systems sometimes present learning problems for novice users. This comparison of four training methods for novice users found that the global tree diagram of the menu system was superior to command sequence and frame presentation methods, and somewhat better than trial and error. Methods were evaluated on the basis of (1) number of target nodes found, (2) mean number of selections to a target node, (3) recall of the menu structure, and (4) subjective rating of ease of learning. | |||
| Characterizing User Navigation Through Complex Data Structures | | BIBA | 93-102 | |
| David Canter; Rod Rivers; Graham Storrs | |||
| As part of the general study of user navigation through interactive data-bases, a set of indices is proposed to characterise users' search sequences. These indices are presented as an attempt to capture some of the psychologically significant aspects of the movement of users within interactive data-bases. An example of the use of the indices is given in reference to an experiment to compare front-ends to a data-base program. Their strengths and weaknesses are discussed in the light of this experiment. Their potential as a basis for the precise definition of search strategies such as browsing and scanning is also considered. | |||
| Keywords for Information Retrieval on Interactive Videotex | | BIBA | 103-112 | |
| Bernard A. Weerdmeester; Rolf H. Van Velthoven; Toon G. M. Vrins | |||
| Searching within public information systems is one of the most complex forms of information retrieval. The use of keywords can facilitate this. The Netherlands PTT has developed an alphanumerically operated keyword search method for Viditel, the Dutch videotex system. Laboratory experiments with untrained users have shown an increase in correctly answered questions and a decrease in search time compared with one of the existing search methods, the numerically operated subject list. Some suggestions for further improvement are given. Implementation of the method in videotex systems is recommended. | |||
| Predicting Performance in Computer Programming Courses | | BIBA | 113-129 | |
| Richard J. Koubek; William K. LeBold; Gavriel Salvendy | |||
| Currently available methods for selecting computer programmers are reviewed. The academic achievement, in high school and in the university, of over 3000 students is reviewed and correlated with their performance in the different computer programming courses. The results revealed that performance in high school and college mathematics and science courses account for up to 50 per cent of the variance in computer programming course performance. The implications of these results for training and selection are discussed. | |||
| The Association between Visual Discomfort and the Use of Visual Display Units | | BIBA | 131-149 | |
| Peter Alan Howarth; Howell Owen Istance | |||
| This paper reports the results of a two-year survey of the visual problems
associated with the use of visual display units (VDUs). The survey examined
both discomfort levels and visual function, and asked whether there were
differences in these measures between subjects who used a VDU in the completion
of their tasks and controls who did not. In total, 202 subjects were examined.
The main study examined four groups of which two, Data Preparation and Word
Processing (WP) used a VDU in the completion of their tasks, while the other
two, General Clerical and Typing (TY), did not. Subjective measures of visual
discomfort and objective measures of visual function were taken at both the
beginning and end of the day.
Two analyses were performed on the data; the first considered all four groups together, and the second directly compared the WP and TY groups -- these two groups being considered well matched. The first analysis showed that statistically significant differences existed between the groups at the end of the day. However, differences were also shown between the groups at the beginning of the day, and when the measure 'change over the day' was used, no significant differences attributable to the VDU were found. The second analysis found no significant differences between the TY and WP groups, nor were any trends apparent. A further study was done on ten subjects who alternated on a daily basis between using a word processor and a typewriter. No significant differences were found between the days using one and those using the other, confirming the above finding. Whilst both optometric measures of visual function and reported visual discomfort did change over the day, we conclude we have no evidence to support the idea that the VDU is in itself a causal factor of these changes to any greater extent than is the paper in a typewriter. | |||
| Reducing Customer Difficulties in International Dialling | | BIB | 151-161 | |
| J. M. Clegg | |||
| Tentative Classification of Global Software | | BIB | 163-170 | |
| Hirokazu Negishi | |||
| "Office Automation, Organisation and the Nature of Work," by Judith Wainwright and Arthur Francis | | BIB | 171-173 | |
| Ken Eason | |||
| "Transnational Data Flows in the Information Age," by C. J. Hamelink | | BIB | 171-173 | |
| J. Eric Davies | |||
| "Computer Networks: Fundamentals and Practice," by M. D. Bacon, A. V. Stokes, and J. Bacon | | BIB | 171-173 | |
| Bill Tuck | |||
| Editorial | | BIB | 175-176 | |
| Tom Stewart | |||
| Viewers' Responses to Delays in Simulated Teletext Reception | | BIBA | 177-188 | |
| William C. Treurniet; Paul J. Hearty; Miguel A. Planas | |||
| In a teletext service, information is retrieved from a sequence of pages broadcast cyclically on a video channel and the mean and variance of system response times are directly related to the number of pages in the cycle. Two experiments were conducted to investigate the maximum tolerable range of such delays. Three degrees of negative viewer response were defined by progressively more conservative criteria for annoyance. Results showed that both the proportion of delays noticed and the proportion of negative viewer responses at each criterion increased linearly with the square root of the system response time. As an example of the effect of criterion, 50 per cent of observers were slightly annoyed or worse with a mean response time of approximately 13 s, while 20 per cent were moderately annoyed or worse with the same delay. In limiting the duration of the broadcast cycle, teletext service providers apparently should consider what proportion of viewers to annoy and to what degree. | |||
| Human Factors Design Considerations for Public Videotex Input Devices | | BIBA | 189-200 | |
| D. Goodman; J. Dickinson; M. J. Francas | |||
| Eight experiments which formed an integral part of a comprehensive human factors investigation on the design of an input device for public videotex services are reported. Results of the first phase led to the design and construction of two simple keypad devices: a linear configuration, with function keys and numerics arranged in horizontal rows, and a square arrangement, with the function keys clustered around a touch-telephone numeric layout. Evaluation of these keypads with 130 novice users was carried out in Phase Two. While there was little difference in performance between the two pads, an interaction between user preference and duration of use was apparent. A slight preference was indicated for the linear pad on initial presentation but preference shifted towards the square arrangement as the duration of use increased. In the third, and major, phase of the research programme, the two simple keypads were compared with a small alphanumeric keypad and a full-sized keyboard. Results showed that novice users consistently performed best with the simple pads and showed a clear preference for these devices over the alphanumeric keypad and full keyboard. The experienced users, who had been trained on the full-sized keyboard, showed no advantage in performance with this device over the simple pads or the alphanumeric keypad but did indicate a clear preference for the keyboard. These results confirm that, with respect to input devices for public videotex systems, differential requirements exist for different types of users. For a diverse group such as the general public, a minimal function keypad appears to be the best compromise device for simple information retrieval tasks. | |||
| Prospective Work Design of a Human-Centred CNC Lathe | | BIBA | 201-214 | |
| J. M. Corbett | |||
| In the operation of many automated systems, the control functions are performed concurrently by human operator and computer. This paper discusses the importance of man-machine interface design for overall system efficiency and described how interface software enables operator and machine to help each other to achieve an effect of which each is separately incapable. Guidelines for the design of a computer numerically controlled (CNC) lathe interface are outlined and the implications for interface design methodology are discussed. | |||
| Analysis of the VDT-Worker Interface | | BIBA | 215-230 | |
| D. G. Wyatt | |||
| A three-dimensional spatial analysis of the VDT-worker interface is given. The relationships between the various parameters involved and the variables in the manual and visual fields are computed, using anthropometric measurements taken from 14 individuals. The effects of different postures are discussed. Fixed-keyboard and separate-keyboard VDTs are compared. | |||
| A Structural Model of the Impact of Physicians' Perceptions of Computers on the Use of Hospital Information Systems | | BIBA | 231-238 | |
| James G. Anderson; Stephen J. Jay; Harlan M. Schweer; Marilyn A. Anderson | |||
| A structural model is developed to specify the effects of physician perceptions of the impact of computers on their use of a computer-based hospital information system (HIS). The overall model consists of a measurement model, which assumes that the observed variables are generated by a small number of unobserved variables or factors, and a structural equation model that relates exogenous and endogenous variables hypothesized as characterizing physician use of the HIS. Parameters of the model are estimated with data from 477 physicians. This approach demonstrates a powerful means of modelling processes involving variables of theoretical interest that cannot be directly observed. | |||
| The Development of a Standardized, Computer-Based Abbreviation Algorithm | | BIBA | 239-247 | |
| Dennis K. McBride; Joseph V. Lambert; Norman E. Lane | |||
| Based upon three simple assumptions about the information-conveying properties of consonants, vowels, syllables and the relative positions of letters and letter groups within parent words, a prototype abbreviation-generating algorithm was constructed. It was reasoned, based on previous studies (Streeter et al. 1980, Reber 1976) and because of the invariant rules which are fundamental to the algorithm, that abbreviations produced by the algorithm should be more readily decoded than naturally produced, popular abbreviations. Experiment I revealed that popular abbreviations were more easily reconstructed than were their ruled-based counterparts, although the margin was reliable only for abbreviations of parent words of relatively long letter length. Results of experiment II demonstrated that when feedback was provided to the subject following each reconstruction, accuracy in decoding the algorithm abbreviations improved with practice. No improvement was observed for subjects who were not provided knowledge of performance. The parent words chosen for study were sampled from a population of commonly used, general communication terms. Consideration is given to the effectiveness of ruled-based procedures when applied to hierarchically defined contexts, as in labelling instrumentation in modern aircraft cockpits and in producing abbreviated commands for advanced, computer-interactive systems. The findings provide an empirical foundation for continued development of the algorithm. | |||
| Icons in Man-Machine Communications | | BIB | 249-254 | |
| Herman Ruge Jervell; Kai A. Olsen | |||
| Are Computer Programmers Knit-Wits? | | BIB | 255-257 | |
| David Fryer | |||
| "Computers in Health Care. Volume 1. Concepts and Issues in Health Care Computing," by H. D. Covvey, N. H. Craven, and N. H. McAlister | | BIB | 259 | |
| Mark Douglas | |||
| Editorial | | BIB | 261-262 | |
| Tom Stewart | |||
| Ergonomics in Information Technology in Europe -- A Review | | BIBA | 263-287 | |
| B. Shackel | |||
| This review of Ergonomics in Information Technology in Europe was done in
three stages. (i) Scientific papers and addresses of other persons/groups were
requested from 52 persons/groups initially contacted. (ii) Visits were made to
the more important groups in nine European countries, and use was made of
opportune visits to the U.S.A. (iii) The papers received, and the extensive
data gathered during the visits, were appraised and the review report was
written.
After discussing the importance of ergonomics for information technology (IT), and outlining the interrelation of human-factors aspects to the total IT system, the growth of research in ITE is documented. The domains and subdomains of ITE are then described and the state of research in these domains is reviewed; at least half of the subdomains of ITE are little researched as yet in Europe. The principal research gaps are recorded. The current state of ITE in Europe and the U.S.A. is then reviewed and compared. As a result it is suggested that a Strategic Programme for Research in ITE (SPRITE) is needed. Such a co-ordinated programme will greatly enlarge the scope of such research in Europe, will develop collaboration between researchers and, especially, will increase the researchers' contact with and value for the European IT industry. | |||
| On the Interaction between System and User Characteristics | | BIBA | 289-308 | |
| Gerrit C. Van Der Veer; Michael J. Tauber; Yvonne Wærn; Bert Van Muylwijk | |||
| The development of a representational framework, based on Moran's Command Language Grammar, for constructing adaptive computer systems is the main topic of this paper. A model of the user interface is developed of which two aspects are discussed: the mental model in the mind of the user and the perceptual model on the side of the machine. Cognitive style and personality factors are considered in their relation to the development of the mental model. The concept of metacommunication is analysed and discussed on all levels of Moran's CLG. | |||
| A Network User Interface: Incorporating Human Factors Guidelines into the ISO Standard for Open Systems Interconnection | | BIBA | 309-326 | |
| G. Hannemyr; P. R. Innocent | |||
| The introduction of standards will hopefully ensure that users can access particular computer resources through a communications network for their own purposes without major problems. The International Standards Organisation (ISO) has developed a seven-layer reference model which is to be used for the purpose of incorporating standards relating to the interconnection of open systems (OSI). It is important that the human factors requirements are considered in relation to this model if the aim of generality of use is to be achieved. This paper considers some of the major human factors requirements and describes an approach to translating them into design standards which can be implemented. The approach starts from a consideration of user activity and develops into a language interface which could reside in layers of the reference model. | |||
| Predicting the Usage of an Advanced Communication Technology | | BIBA | 327-335 | |
| Charles E. Grantham; Jerry J. Vaske | |||
| Despite the advantages associated with computer-mediated communication technologies, many people do not use such systems even when they are readily available. Efforts to identify the variables which mediate the relationship between the introduction of such technologies and their use have only recently become the focal point of systematic investigation. This paper explores the effects of three categories of predictor variables on the usage of a voice store and forward communication system. The variables include the individuals' attitudes toward the technology, their prior experiences with the voice message system, and the nature of their communication pattern. Data for this analysis were obtained from a mailed survey (N=279, response rate=78 per cent) of employees who were listed as subscribers of the company's voice mail (i.e., VOX). Regression analyses indicate that the strongest predictor of VOX usage was the respondent's attitude toward the system. Length of prior experience was also positively associated with the extent of current usage. Respondents, however, were less likely to use the system when communicating with subordinates. Implications for the design and implementation of computer-mediated communication channels are discussed. | |||
| Generating English Paraphrases from Relational Query Expressions | | BIBA | 337-348 | |
| Barry G. T. Lowden; Anne De Roeck | |||
| Of the many problems facing the casual user of a data-base enquiry system probably the most difficult is gaining a competent understanding of the associated query language. Given that he manages to construct a well-formed query expression there is no guarantee that it exactly reflects the original question. The research described here concerns the design of an interpreter from a formal query language to natural language to aid query verification in a relational data-base environment. The system is being developed to work in conjunction with the ICL Natural Language enquiry interface NEL which translates English query expressions into the formal query language QUERYMASTER. The requirements of a natural-language paraphraser are first discussed and the nature of an intermediate representation is defined and motivated with respect to an applied relational calculus. Consideration is then given to choosing a suitable underlying framework with which to underpin the practical work and the choice of Lexical Functional Grammar as the guiding theory is explained. Finally, the research is set in the context of a longer-term programme to construct a multi-purpose user interface incorporating facilities for handling data-base metaknowledge and query building. | |||
| Some Psychological Attributes of Potential Computer Command Names | | BIBA | 349-365 | |
| Yvonne Rogers; D. J. Oborne | |||
| One of the major difficulties that users may experience when interacting
with computer systems is remembering the system functions that relate to
particular command names. This paper considers the problem by evaluating
various semantic attributes of a set of verbs in relation to the underlying
psychological processes involved in a naming task.
An initial investigation carried out to obtain imagery and concrete-abstractness ratings for the verbs (most of which were also existing computer commands) showed not only a wide range of ratings for attributes of the stimuli, but also that the majority of 'command' verbs were rated as being highly abstract and low in imagery. A second experiment investigated the factors of imagery and word frequency as a function of the ease with which 'command' verbs were elicited from an appropriate verbal description. The results demonstrated a complex interaction, in so far as low frequency, high imagery verbs were elicited more easily than those which have high frequency and low imagery attributes. The findings of these two investigation were discussed in relation to the ways in which imagery associations for verbs may influence user performance in memory tasks involving computer systems. | |||