The use of analytical models in human-computer interface design

Some of the many analytical models in human-computer interface design that are currently being developed are described. The usefulness of analytical models for human-computer interface design is evaluated. Can the use of analytical models be recommended to interface designers? The answer, based on the empirical research summarized here, is: not at this time. There are too many unanswered questions concerning the validity of models and their ability to meet the practical needs of design organizations

OBTENCIÓN DE CONOCIMIENTO EMPÍRICO SOBRE LA CALIDAD DE CASOS DE USO

Estudio secundario empírico diseñado para identificar qué aspectos de los Casos de Uso son evaluados, así como el formato de descripción y el dominio donde son experimentados.Ferrando Moragues, JA. (2010). OBTENCIÓN DE CONOCIMIENTO EMPÍRICO SOBRE LA CALIDAD DE CASOS DE USO. http://hdl.handle.net/10251/13970Archivo delegad

Heuristics for use case descriptions.

Use cases, as part of the Unified Modelling Language, have become an industry standard. The major focus has been on the use case diagram. It is only recently that any detailed attention has been paid to the use case description. The description should be written in such a way as to make it communicable to its reader. However, this does not always appear to be the case. This thesis presents the 7 C's of Communicability as quality features of use case descriptions that make them more comprehensible. The 7 C's are derived from software engineering best practice on use case descriptions and from theories of text comprehension. To help in writing descriptions, the CP Use Case Writing Rules are proposed, a small set of guidelines derived from the 7 C's. Going beyond requirements, software engineers often employ use case descriptions to help them build initial design models of the proposed system. Despite Jacobson's claim that "objects naturally fall out of use cases", fording design-oriented classes and objects in use case descriptions is shown not to be straightforward. This thesis proposes a Question Set which allows the engineer to interrogate the description for important elements of specification and design. Experimentation shows that the CP Writing Rules furnish descriptions that are as comprehensible as those written by other guidelines proposed in the literature. It is also suggested that descriptions be written from the perspective of their intended audience. The limitations of conducting requirements engineering experiments using students are considered and it is suggested that experimenters should not expect large effects from the results. An industrial case study shows that although the CP Rules could not be applied to all events in the use case descriptions, they were applied to most and at varying levels of abstraction. The case study showed that the 7 C's did identify problems with the written descriptions. The Question Set was well received by the case study stakeholders, but it was considered time consuming. One of the overriding findings from the case study was that project time constraints would not allow the company to use the techniques suggested, although they recognised the need to do so. Automation would make industrial application of the CP Rules and 7 C's more feasible

The use of analytical models in human-computer interface design

Recently, a large number of human-computer interface (HCI) researchers have investigated building analytical models of the user, which are often implemented as computer models. These models simulate the cognitive processes and task knowledge of the user in ways that allow a researcher or designer to estimate various aspects of an interface's usability, such as when user errors are likely to occur. This information can lead to design improvements. Analytical models can supplement design guidelines by providing designers rigorous ways of analyzing the information-processing requirements of specific tasks (i.e., task analysis). These models offer the potential of improving early designs and replacing some of the early phases of usability testing, thus reducing the cost of interface design. This paper describes some of the many analytical models that are currently being developed and evaluates the usefulness of analytical models for human-computer interface design. This paper will focus on computational, analytical models, such as the GOMS model, rather than less formal, verbal models, because the more exact predictions and task descriptions of computational models may be useful to designers. The paper also discusses some of the practical requirements for using analytical models in complex design organizations such as NASA

Semi-automatic assessment of students' graph-based diagrams

Diagrams are increasingly used in many design methods, and are being taught in a variety of contexts in higher education such as database conceptual design or software design in computer science. They are an important part of many assessments. Currently computer aided assessments are widely used for multiple choice questions. They lack the ability to assess a student’s knowledge in a more comprehensive way, which is required for diagram-type student work. The aim of this research is to develop a semi-automatic assessment framework, which enables the use of computer to support the assessment process of diagrammatic solutions, with the focus of ensuring the consistency of grades and feedback on solutions. A novel trace model, that captures design traces of student solutions, was developed as a part of the framework and was used to provide the matching criteria for grouping the solutions. A new marking style, partial marking, was developed to mark these solution groups manually. The Case-Based Reasoning method is utilised in the framework to mark some of the groups automatically. A guideline for scenario writing was proposed to increase the efficiency of automatic marking. A prototype diagram editor, a marking tool and scenario writing environment were implemented for the proposed framework in order to demonstrate proof of concept. The results of experiments show that the framework is feasible to use in the formative assessment and it provides consistent marking and personalised feedback to the students. The framework also has the potential to significantly reduce the time and effort required by the examiner to mark student diagrams. Although the constructed framework was specifically used for the assessment of database diagrams, the framework is generic enough to be used for other types of graph-based diagram

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 337)

This bibliography lists 400 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during May 1990. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

Semi-Automatic assessment of students' graph-based diagrams

Diagrams are increasingly used in many design methods, and are being taught in a variety of contexts in higher education such as database conceptual design or software design in computer science. They are an important part of many assessments. Currently computer aided assessments are widely used for multiple choice questions. They lack the ability to assess a student's knowledge in a more comprehensive way, which is required for diagram-type student work. The aim of this research is to develop a semi-automatic assessment framework, which enables the use of computer to support the assessment process of diagrammatic solutions, with the focus of ensuring the consistency of grades and feedback on solutions. A novel trace model, that captures design traces of student solutions, was developed as a part of the framework and was used to provide the matching criteria for grouping the solutions. A new marking style, partial marking, was developed to mark these solution groups manually. The Case-Based Reasoning method is utilised in the framework to mark some of the groups automatically. A guideline for scenario writing was proposed to increase the efficiency of automatic marking. A prototype diagram editor, a marking tool and scenario writing environment were implemented for the proposed framework in order to demonstrate proof of concept. The results of experiments show that the framework is feasible to use in the formative assessment and it provides consistent marking and personalised feedback to the students. The framework also has the potential to significantly reduce the time and effort required by the examiner to mark student diagrams. Although the constructed framework was specifically used for the assessment of database diagrams, the framework is generic enough to be used for other types of graph-based diagram.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Requirement validation with enactable descriptions of use cases.

The validation of stakeholder requirements for a software system is a pivotal activity for any nontrivial software development project. Often, differences in knowledge regarding development issues, and knowledge regarding the problem domain, impede the elaboration of requirements amongst developers and stakeholders. A description technique that provides a user perspective of the system behaviour is likely to enhance shared understanding between the developers and stakeholders. The Unified Modelling Language (UML) use case is such a notation. Use cases describe the behaviour of a system (using natural language) in terms of interactions between the external users and the system. Since the standardisation of the UML by the Object Management Group in 1997, much research has been devoted to use cases. Some researchers have focussed on the provision of writing guidelines for use case specifications whereas others have focussed on the application of formal techniques. This thesis investigates the adequacy of the use case description for the specification and validation of software behaviour. In particular, the thesis argues that whereas the user-system interaction scheme underpins the essence of the use case notation, the UML specification of the use case does not provide a mechanism by which use cases can describe dependencies amongst constituent interaction steps. Clarifying these issues is crucial for validating the adequacy of the specification against stakeholder expectations. This thesis proposes a state-based approach (the Educator approach) to use case specification where constituent events are augmented with pre and post states to express both intra-use case and inter-use case dependencies. Use case events are enacted to visualise implied behaviour, thereby enhancing shared understanding among users and developers. Moreover, enaction provides an early "feel" of the behaviour that would result from the implementation of the specification. The Educator approach and the enaction of descriptions are supported by a prototype environment, the EducatorTool, developed to demonstrate the efficacy and novelty of the approach. To validate the work presented in this thesis an industrial study, involving the specification of realtime control software, is reported. The study involves the analysis of use case specifications of the subsystems prior to the application of the proposed approach, and the analysis of the specification where the approach and tool support are applied. This way, it is possible to determine the efficacy of the Educator approach within an industrial setting