Ann Blandford

Four Easy Pieces for Assessing the Usability of Multimodal Interaction: The Care Properties

We propose the CARE properties as a simple way of characterisin g and assessing aspects of multimodal interaction: the Complementarity, Assignment, Redundancy, and Equivalence that may occur between the interaction techniques available in a multimodal user interface. We provide a formal definition of these properties and use the notion of compatibility to show how the system CARE properties interact with user CARE-like properties in the design of a system. The discussion is illustrated with MATIS, a Multimodal Air Travel Information System.

Analytical usability evaluation for digital libraries: a case study

There are two main kinds of approach to considering usability of any system: empirical and analytical. Empirical techniques involve testing systems with users, whereas analytical techniques involve usability personnel assessing systems using established theories and methods. We report here on a set of studies in which four different techniques were applied to various digital libraries, focusing on the strengths, limitations and scope of each approach. Two of the techniques, heuristic evaluation and cognitive walkthrough, were applied in text-book fashion, because there was no obvious way to contextualize them to the digital libraries (DL) domain. For the third, claims analysis, it was possible to develop a set of reusable scenarios and personas that relate the approach specifically to DL development. The fourth technique, CASSM, relates explicitly to the DL domain by combining empirical data with an analytical approach. We have found that heuristic evaluation and cognitive walkthrough only address superficial aspects of interface design (but are good for that), whereas claims analysis and CASSM can help identify deeper conceptual difficulties (but demand greater skill of the analyst). However, none fit seamlessly with existing digital library development practices, highlighting an important area for further work to support improved usability.

Use of multiple digital libraries: a case study

The aim of the work reported here was to better understand the usabili ty issues raised when digital libraries are used in a natural setting. The method used was a protocol analysis of users working on a task of their own choosing to retrieve documents from publicly available digital libraries. Various classes of usability difficulties were found. Here, we focus on use in context - that is, usability concerns that arise from the fact that libraries are accessed in particular ways, under technically and organisationally imposed constraints, and that use of any particular resource is discretionary. The concepts from an Interaction Framework, which provides support for reasoning about patterns of interaction between users and systems, are applied to understand interaction issues.

Understanding emergency medical dispatch in terms of distributed cognition: a case study

Emergency medical dispatch (EMD) is typically a team activity, requiring fluid coordination and communication between team members. Such working situations have often been described in terms of distributed cognition (DC), a framework for understanding team working. DC takes account of factors such as shared representations and artefacts to support reasoning about team working. Although the language of DC has been developed over several years, little attention has been paid to developing a methodology or reusable representation which supports reasoning about an interactive system from a DC perspective. We present a case study in which we developed a method for constructing a DC account of team working in the domain of EMD, focusing on the use of the method for describing an existing EMD work system, identifying sources of weakness in that system, and reasoning about the likely consequences of redesign of the system. The resulting DC descriptions have yielded new insights into the design of EMD work and of tools to support that work within a large EMD centre.

Group and Individual Time Management Tools: What You Get is Not What You Need

Abstract: Some studies of diaries and scheduling systems have considered how individuals use diaries with a view to proposing requirements for computerised time management tools. Others have focused on the criteria for success of group scheduling systems. Few have paid attention to how people use a battery of tools as an ensemble. This interview study reports how users exploit paper, personal digital assistants (PDAs) and a group scheduling system for their time management. As with earlier studies, we find many shortcomings of different technologies, but studying the ensemble rather than individual tools points towards a different conclusion: rather than aiming towards producing electronic time management tools that replace existing paper-based tools, we should be aiming to understand the relative strengths and weaknesses of each technology and look towards more seamless integration between tools. In particular, the requirements for scheduling and those for more responsive, fluid time management conflict in ways that demand different kinds of support.

Coming across information serendipitously - Part 1: A process model

Purpose – This research seeks to gain a detailed understanding of how researchers come across information serendipitously, grounded in real‐world examples. This research was undertaken to enrich the theoretical understanding of this slippery phenomenon.Design/methodology/approach – Semi‐structured critical incident interviews were conducted with 28 interdisciplinary researchers. Interviewees were asked to discuss memorable examples of coming across information serendipitously from their research or everyday life. The data collection and analysis process followed many of the core principles of grounded theory methodology.Findings – The examples provided were varied, but shared common elements (they involved a mix of unexpectedness and insight and led to a valuable, unanticipated outcome). These elements form part of an empirically grounded process model of serendipity. In this model, a new connection is made that involves a mix of unexpectedness and insight and has the potential to lead to a valuable outco...

An approach to formal verification of human–computer interaction

The correct functioning of interactive computer systems depends on both the faultless operation of the device and correct human actions. In this paper, we focus on system malfunctions due to human actions. We present abstract principles that generate cognitively plausible human behaviour. These principles are then formalised in a higher-order logic as a generic, and so retargetable, cognitive architecture, based on results from cognitive psychology. We instantiate the generic cognitive architecture to obtain specific user models. These are then used in a series of case studies on the formal verification of simple interactive systems. By doing this, we demonstrate that our verification methodology can detect a variety of realistic, potentially erroneous actions, which emerge from the combination of a poorly designed device and cognitively plausible human behaviour.

The effect of interruptions on postcompletion and other procedural errors: an account based on the activation-based goal memory model.

A postcompletion error (PCE) is a specific kind of cognitive slip that involves omitting a final task step after the main goal of the task is accomplished. It is notoriously difficult to provoke (and hence study) slips under experimental conditions. In this paper, the authors present an experimental task paradigm that has been shown to be effective for studying PCEs in routine procedural tasks. Two studies were carried out to examine the effect of interruption position and task structure on the prevalence of PCEs. It was found that significantly more PCEs were obtained when an interruption occurred just before the PC step than when an interruption occurred at any other position in the task. The authors account for this effect in terms of Altmann and Traftons activation-based goal memory model. The same interruption effect was obtained for some, but not all, other procedural errors; the authors discuss the nature of these errors and likely explanations for the differences.

Social empowerment and exclusion: A case study on digital libraries

This article reports on work studying how technology can empower or exclude its users due to interactions between social context, system design, and implementation. The analysis is based around the introduction and use of digital libraries in four different settings, three clinical and one academic. Across the four settings, in-depth interview and focus group data was collected from 144 users and analyzed with reference to “communities of practice”. The four settings represent three different approaches to digital library implementation: making digital library resources available from existing computer systems in peoples offices and the library (a traditional approach); making computer systems, and hence digital libraries, available in shared spaces (in this case, hospital wards); and employing information intermediaries to work with staff and library resources. These different approaches engendered different perceptions of the technology. The traditional approach produced perceptions of technology as being irrelevant for current needs and community practices. Making technology available within shared physical space but with poor design, support, and implementation procedures was widely perceived as a threat to current organizational structures. In contrast, technology implemented within the community which could adapt and change practices according to individual and group needs, supported by an information intermediary, was seen as empowering to both the community and the individual. We relate the findings to a discussion of evolutionary and revolutionary approaches to design and to the concept of communities of practice.

A resilience markers framework for small teams

Processes that enable an effective response to unexpected events and vulnerabilities that lie outside the scope of formal procedures can be described as being resilient. There are many such descriptions of resilience within and across different domains. Comparison and generalisation is difficult because resilience is not a component of a system and should be understood as an emergent property. Here we provide a framework for reasoning about resilience that requires representation of the level of analysis (from the individual to operational), a traceable link from abstract theory to specific observations, resilience mechanisms, and contextual factors. This moves forward an agenda to systematically observe concrete manifestations of resilience within and across domains. We illustrate the application of the framework by considering a case study of the performance of nuclear power plant (NPP) operators in an experimental scenario. This paper focuses on the small team level of analysis. The framework presented here provides the basis for developing concrete measures for improving the resilience of organisations through training, system design, and organisational learning.