Michael R. Kibby

Strath Tutor © the development and evaluation of a learning-by-browsing system on the Macintosh

Abstract An account is given of the major influences on the design of StrathTutor, a leaming-by-browsing tutorial system for the Apple Macintosh computer. In CAL programming, explicit links between frames in a tutorial represent a limiting and expensive approach to authoring and Al techniques are widely expected to point the way to future progress. Intelligent CAL appears to be concentrating on problems thought to be amenable to the expert system approach, i.e. highly procedural and well analysed tasks. Developments in technology are tending to force the pace. Interactive laser-discs and CD-ROMs allow fast random access to extensive graphic and textual data. Learning will come to include interaction with complex data structures by means of browsing, scanning, wandering and exploring. Navigation through the data, and ease of authoring, will require more sophisticated forms of knowledge representation than indexation, including semantic networks, production rules and error libraries. Ultimately, the issue of learner control will require to be confronted, basically because the best possible model of the learners state of knowledge is that residing in the learner. In StrathTutor, knowledge is represented by attribute coding of each frame, influenced by theoretical work from two apparently unrelated areas: the computational model of human memory MINERVA 2 and expert systems based on pattern recognition. Information in the form of frame contents and as attributes is separate from the tutorial shell which conducts the interaction with the learner, with the aid of the Macintosh user interface. STmaker operates in “authoring” mode allowing the composing of new tutorials, and STviewer replays a trace of a students path through a tutorial. The menu choices in StrathTutor are described. Evaluation of a system such as Strath Tutor is being attempted in three ways: comparison of effectiveness of learning with traditional forms of instruction, cognitive analysis while the student learns, and formal and informal assessments in the hands of both teachers and students. Groups using Strath Tutor have shown significant learning. The inherent difficulties encountered have led to better modes of experimentation being devised, and to suggested modification of Strath Tutor itself.

Blocks to the effective use of information technology in higher education

Abstract This paper reports on the outcome of a seminar addressing issues in the exploitation of IT in teaching within Universities in the U.K. The seminar brought together experts with a range of experience in the use of educational technology, and focused on educational and organisational issues rather than on technical ones. Three surveys of the views of University lecturers on the use of computers in teaching, and the associated problems, are reported, followed by discussion of educational and organisational routes to lowering some of the existing barriers to more effective applications of educational technology.

Authoring and evaluation of hypermedia for education

Abstract Hypermedia encompasses the modes of learning and interaction associated with conventional CAL, but it also allows greater learner control, access to multimedia learning materials and a variety of modalities of interaction with the learning material which are only now becoming apparent. Nevertheless, for a hypermedia document to be educationally effective, the author must consider the learning goals and activities it must support, how the nature of the domain will relate to the learning activities, and how learners will differ, and then provide appropriate support tools. Authoring large hypermedia documents demands facilities to manage links, and to create them automatically. Methods considered included the creation of generic links, applicable to more than one document, use of knowledge-based rules to generate links, and the use of file interchange formats for reusability of information. Authors should avoid the dominant browse and retrieve model and consider a range of activities—in any case simple hypertext has been shown to be insufficient for effective learning. Evaluation of such systems and materials in use has many facets, including usability, the effectiveness of guidance tools, the learning achieved. Evaluation of hypermedia systems is different from CAL because of the new vocabulary and syntax of interaction which is required.

An approach to the evaluation of hypermedia

Abstract This paper discusses some methods which may be applied to the evaluation of hypermedia, based on the six models described by Lawton[6]: the classical experimental model; the research and developmental model: the illuminative model; the briefing decision-makers model; the teacher as researcher model; and the case-study model. The use of a number of techniques are discussed, including observation, self-report measures, interviews, automated measures and psychometric tests. Criteria are provided for deciding on an approach which is congruent with the objectives of evaluation.

Small Group Collaborative Discovery Learning from Hypertext

A study is reported in which pairs of students were set the task of learning specified material from a hypertext-based discovery learning system (StrathTutor). Conventional pre- to post-test change measures of learning were employed and demonstrated an average learning gain of some 20%, which was highly significant. In addition, the pairs were videotaped as they used the system together and the resulting dialogue was fully transcribed and annotated to reflect the subjects’ interactions, both with each other and with the machine. In this paper, we compare those dialogues in which the subjects were relatively more successful at the learning task, with those dialogues corresponding to less successful learning outcomes in an attempt to illuminate the process aspects of collaborative learning around the computer.

Effects of chronic administration of drugs which modify neurotransmitter re-uptake, storage and turnover on levels of tyrosine and tryptophan hydroxylase in rat brain

Abstract Oral ingestion of d-amphetamine at a rate of 11·7 ± 2 mg/kg/24 hr (mean ± S.D.) failed to significantly alter fore- and midbrain tyrosine hydroxylase activities, measured in vitro, with respect to control activities after 3 or 7 days pretreatment, or hindbrain levels of the enzyme after 3 days pretreatment. Similarly, prolonged pretreatment with reserpine (1 mg/kg/24 hr), the dopamine-β-hydroxylase inhibitor FLA-63 (25 mg/kg/24hr) or the DOPA decarboxylase inhibitor NSD1015 (25 mg/kg/24 hr) did not change fore- and midbrain levels of the enzyme, either when these drugs were given alone, or in combination with (d-amphetamine. However, fore- and midbrain tyrosine hydroxylase levels in animals pretreated for 7 days with amphetamine alone were significantly enhanced in comparison with animals pretreated with reserpine, or an amphetamine/reserpine combination. The same trend may have been observable after 3 days, but failed to attain significance within this period. (d-Amphetamine, reserpine and an amphetamine/reserpine combination failed to alter fore- and midbrain tryptophan hydroxylase levels after 7 days pretreatment, and neither amphetamine nor an amphetamine/NSD1015 combination altered hindbrain levels of the enzyme. Seven days pretreatment with the tricyclic antidepressant drugs imipramine and iprindole (10 mg/kg/48 hr) exerted no effect on fore- and midbrain tryptophan hydroxylase levels. These results indicate that hydroxylase levels in central monoamine neurones, unlike sympathetic postganglionic neurones, appear to be relatively insensitive to agents which lead to prolonged alteration of neurotransmitter turnover rates. This may reflect differences between peripheral and central monoamine neurones in terms of both anatomical and functional relationships.

Teaching teachers to use HyperCard: a minimal manual approach

Untrained computer users often find traditional comprehensive manuals difficult and daunting. A minimal manual for HyperCard on the Macintosh was developed to ascertain the practicability of untrained classroom teachers learning HyperCard. To this end, the extent and type of use of the manual and software by teachers over a period of occasional use in their own time was recorded. Certain patterns of use were identified from self-report forms completed by 23 of the original 27 subjects and from structured proficiency tests performed in the presence of an interviewer. The manual was rated low on difficulty and high on usefulness. While only three were judged to be able to create their own stacks at the end of the course, most subjects achieved high proficiency up to that level within an average study time of 27 hours. It is concluded that the most effective use of HyperCard by teachers is in using their skills to modify existing stacks for their teaching rather than to create new materials from scratch.

The electronic spreadsheet as a general–purpose programming tool

Electronic spreadsheets computerise the traditional layout of any tabulation or complex calculation done with pencil, paper and calculator. They therefore have great potential in aiding routine calculations which might be done by these means or with a small BASIC computer program. Their simple structure and strong affinity with traditional methods make them particularly suitable for those who have not yet mastered the art of programming. However, a necessarily brief review of their application to science and technology demonstrates that this potential is not being realised in comparison with their wide-spread usage in the business world. The application of both Multiplan and Visicalc running respectively on the Macintosh and the Apple IIe microcomputers in four types of calculation is demonstrated: tabulation, curve-fitting and statistics, simulation, and numerical approximation. Advantages are found in the concurrent display of data and results, the ease of correction or modification of data and the escape from traditional linear programming methods. The spreadsheet format imposes its own constraints. It is not so flexible as BASIC, it demands more memory and may have a slower execution time than a program written in a high-level language, and it is more difficult to produce graphical output.

The matrix representation of pharmacokinetic models

Abstract An equation is developed from the matrix of rate constants which describes the behaviour of linear pharmacokinetic models for any initial condition as a function of time. This general matrix equation is then used to derive analogous expressions for drug distribution after a period of infusion, at the steady state, or during a multiple constant-dosage regimen. Matrix expressions are also derived for areas under drug concentration curves for any compartment after single doses or during multiple dosing. General matrix equations are shown to yield loading dosage schedules to achieve plateau concentrations throughout any open system. It is suggested that matrix methods have advantages over previously used mathematical techniques in pharmacokinetics in the simplicity of the algebraic expressions, and their ease of manipulation. An algebraic example of an open two-compartment model is worked to indicate the applicability of the general expressions.

Four spreadsheet templates for the laboratory

Four spreadsheet templates have been devised to ease certain laboratory operations, namely preparing buffers by mixing solutions, calculating required rotor speeds to achieve particular g-values, preparing and utilising isokinetic gradients to determine sedimentation coefficients, and calculating purification tables. Their use in designing experiments is described briefly.