Mark D. Dunlop

The Challenge of Mobile Devices for Human Computer Interaction

Abstract:

Predictive text entry methods for mobile phones

Mobile phone networks are increasingly supporting the transmission of textual messages between mobile phones and between mobile phones and other services. This paper describes the current text entry method on mobile phones and describes a new text entry method using a single key-press per letter together with a large dictionary of words for disambiguation. This approach, which is similar to technology recently licensed, independently, to several phone companies, is then extended with automatic word completion. The paper reports the results of initial user tests comparing the text entry methods, analysis of word clashes with the dictionary-based methods and keystroke level modelling of the different input methods.

Image retrieval by hypertext links

This paper presents a model for retrieval of images from a large World Wide Web based collection. Rather than considering complex visual recognition algorithms, the model presented is based on combining evidence of the text content and hypertext structure of the Web. The paper shows that certain types of query are amply served by this form of representation. It also presents a novel means of gathering relevance judgements.

Hypermedia and free text retrieval

Abstract This paper discusses aspects of multimedia document bases and how access to documents held on a computer-based system can be achieved; in particular, the current access methods of hypermedia and free text information retrieval are discussed. Browsing-based hypermedia systems provide ease of use for novice users and equal access to any media; however, they typically perform poorly with very large document bases. In contrast, query-based free text retrieval systems are typically designed to work with very large document bases, but have very poor multimedia capabilities. This paper presents a hybrid between these two traditional fields of information retrieval, together with a technique for using contextual information to provide access, through query, to documents that cannot be accessed by content (e.g., images). Two experiments are then presented that were carried out to test this approach. Finally, the paper gives a brief discussion of a prototype implementation, which provides access to mixed media information by query or browsing, and user-interface issues are discussed.

An Experimental Investigation into Wayfinding Directions for Visually Impaired People

In recent years, there has been an escalation of orientation and wayfinding technologies and systems for visually impaired people. These technological advancements, however, have not been matched by a suitable investigation of human-computer interaction (e.g. designing navigation aids for people who form different cognitive maps for navigation). The aim of this study is to investigate whether a group of sighted participants and a group of visually impaired participants experience a difference in mental and physical demands when given two different sets of verbal instructions directing them to four landmarks. The content of the first set of instructions was proportioned to route descriptions derived from sighted people, and the second set proportioned to descriptions derived from visually impaired people. The objective assessment involved measuring the time taken by participants to reach landmarks and the number of deviations that occurred. A NASA–Task Load Index questionnaire provided an indication of participants subjective perception of workload. The results revealed that instructions formed from visually impaired people resulted in a lower weighted workload score, less minor deviations, and quicker times for visually impaired participants. In contrast, these instructions were found to cause a higher weighted workload score for sighted participants. The results are discussed in relation to the issue of personalisation of mobile context-aware systems for visually impaired people.

Time, relevance and interaction modelling for information retrieval

The most common method for assessing the worth of an information retrieval (lR) system is through precision and recall graphs. These graphs show how precise an IR engine is when working at fixed levels of recall. This paper introduces number-lo-view graphs, a new graphing method based on an early evaluation measure, which supplement precisionrecall graphs by plotting the number of relevant documents a user wishes against the number of documents they would have to view to encounter them. The paper also proposes a step forward from number-to-view graphs that directly includes presentation, interface and temporal issues within the same frame work as engine effectiveness: time-to-view graphs. Taken together, these graphs and models introduce a new evaluation approach called Expected Search Duration.

The effect of accessing nonmatching documents on relevance feedback

Traditional information retrieval (IR) systems only allow users access to documents that match their current query, and therefore, users can only give relevance feedback on matching documents (or those with a matching strength greater than a set threshold. This article shows that, in systems that allow access to nonmatching documents (e.g., hybrid hypertext and information retrieval systems), the strength of the effect of giving relevance feedback varies between matching and nonmatching documents. For positive feedback the results shown here are encouraging, as they can be justified by an intuitive view of the process. However, for negative feedback the results show behavior that cannot easily be justified and that varies greatly depending on the model of feedback used.

Text input on a smart watch

Smart watches provide users with access to many applications directly from their wrists, without the need to touch their smartphones. While applications such as email, messaging, calendar, and social networking provide views on the watch, there is normally no text-entry method, so users cannot reply on the same device. Here, the authors introduce their interaction design and an optimized alphabetic layout for smart-watch text entry, and present a lab evaluation of an implemented prototype using the OpenAdaptxt engine on a Sony SmartWatch 2. While raising some problems, the feedback from study participants indicates that reasonable quality and speed is achievable on a smart watch and encourages future work in this area. This article is part of a special issue on wearable computing.

Reflections on Mira: interactive evaluation in information retrieval

Evaluation in information retrieval (IR) has focussed largely on noninteractive evaluation of text retrieval systems. This is increasingly at odds with how people use modern IR systems: in highly interactive settings to access linked, multimedia information. Furthermore, this approach ignores potential improvements through better interface design. In 1996, the Commission of the European Union Information Technologies Programme funded a 3‐year working group, Mira, to discuss and advance research in the area of evaluation frameworks for interactive and multimedia IR applications. Led by Keith van Rijsbergen, Steve Draper, and myself from Glasgow University, this working group brought together many of the leading researchers in the evaluation domain from both the IR and human–computer interaction (HCI) communities. This article presents my personal view of the main lines of discussion that took place throughout Mira: importing and adapting evaluation techniques from HCI, evaluating at different levels as appropriate, evaluating against different types of relevance and the new challenges that drive the need for rethinking the old evaluation approaches. The article concludes that we need to consider more varied forms of evaluation to complement engine evaluation.

Mobile and Ubiquitous Information Access

We discuss how the wireless-mobile revolution will change the notion of relevance in information retrieval. We distinguish between classical relevance (e-relevance) and relevance for wireless/mobile information retrieval (w-relevance). Starting from a four-dimensional model of e-relevance previously developed by one of us, we discuss how, in an ubiquitous computing environment, much more information will be available, and how it is therefore likely that w-relevance will be more important than e-relevance to survive information overload. The similarities and differences between e-relevance and w-relevance are described, and we show that there are more differences than one might think at first. We specifically analyze the role that beyond-topical criteria have in the w-relevance case, and we show some examples to clarify and support our position.