Martin Halvey

Some like it hot: thermal feedback for mobile devices

Thermal stimulation is a rich, emotive and salient feedback channel that is well suited to HCI, but one that is yet to be fully investigated. Thermal feedback may be suited to environments that are too loud for audio or too bumpy for vibrotactile feedback. This paper presents two studies into how well users could detect hot and cold stimuli presented to the fingertips, the palm, the dorsal surface of the forearm and the dorsal surface of the upper arm. Evaluations were carried out in static and mobile settings. Results showed that the palm is most sensitive, cold is more perceivable and comfortable than warm and that stronger and faster-changing stimuli are more detectable but less comfortable. Guidelines for the design of thermal feedback are outlined, with attention paid to perceptual and hedonic factors.

Predicting navigation patterns on the mobile-internet using time of the week

A predictive analysis of user navigation in the Internet is presented that exploits time-of-the-week data. Specifically, we investigate time as an environmental factor in making predictions about user navigation. An analysis is carried out of a large sample of user, navigation data (over 3.7 million sessions from 0.5 million users) in a mobile-Internet context to determine whether user surfing patterns vary depending on the time of the week on which they occur. We find that the use of time improves the predictive accuracy of navigation models.

The effects of walking, feedback and control method on pressure-based interaction

This paper presents a study looking into the effects of walking and the use of visual and audio feedback on the application of pressure for linear targeting. Positional and Rate-based control methods are compared in order to determine which allows for more stable and accurate selections, both while sitting and mobile. Results suggest that Rate-based control is superior for both mobile (walking) and static (sitting) linear targeting, and that mobility significantly increases errors, selection time and subjective workload. The use of only audio feedback significantly increased errors and task time for Positional control and static Rate-based control, but not mobile Rate-based control. Despite this, the results still suggest that audio control of pressure interaction while walking is highly accurate and usable.

Search trails using user feedback to improve video search

In this paper we present an innovative approach for aiding users in the difficult task of video search. We use community based feedback mined from the interactions of previous users of our video search system to aid users in their search tasks. This feedback is the basis for providing recommendations to users of our video retrieval system. The ultimate goal of this system is to improve the quality of the results that users find, and in doing so, help users to explore a large and difficult information space and help them consider search options that they may not have considered otherwise. In particular we wish to make the difficult task of search for video much easier for users. The results of a user evaluation indicate that we achieved our goals, the performance of the users in retrieving relevant videos improved, and users were able to explore the collection to a greater extent.

Baby it's cold outside: the influence of ambient temperature and humidity on thermal feedback

Thermal feedback is a new area of research in HCI and, as such, there has been very little investigation of the impact of environmental factors on its use for interaction. To address this shortcoming we conducted an experiment to investigate how ambient temperature and humidity could affect the usability of thermal feedback. If environmental conditions affect perception significantly, then it may not be suitable for mobile interactions. Evaluations were conducted outdoors in varying environmental conditions over a period of 5 months. Results showed that the ambient temperature has a significant impact on peoples ability to detect stimuli and also their perception of these stimuli. Humidity has a negligible effect for most humidity values. Despite this, previous thermal feedback design recommendations still hold in varying temperatures and humidities showing that thermal feedback is a useful tool for mobile interaction.

An asynchronous collaborative search system for online video search

There are a number of multimedia tasks and environments that can be collaborative in nature and involve contributions from more than one individual. Examples of such tasks include organising photographs or videos from multiple people from a large event, students working together to complete a class project, or artists and/or animators working on a production. Despite this, current state of the art applications that have been created to assist in multimedia search and organisation focus on a single user searching alone and do not take into consideration the collaborative nature of a large number of multimedia tasks. The limited work in collaborative search for multimedia applications has concentrated mostly on synchronous, and quite often co-located, collaboration between persons. However, these collaborative scenarios are not always practical or feasible. In order to overcome these shortcomings we have created an innovative system for online video search, which provides mechanisms for groups of users to collaborate both asynchronously and remotely on video search tasks. In order to evaluate our system an user evaluation was conducted. This evaluation simulated multiple conditions and scenarios for collaboration, varying on awareness, division of labour, sense making and persistence. The outcome of this evaluation demonstrates the benefit and usability of our system for asynchronous and remote collaboration between users. In addition the results of this evaluation provide a comparison between implicit and explicit collaboration in the same search system.

Why aren't Users Using Protection? Investigating the Usability of Smartphone Locking

One of the main reasons why smartphone users do not adopt screen locking mechanisms is due to the inefficiency of entering a PIN/pattern each time they use their phone. To address this problem we designed a context-sensitive screen locking application which asked participants to enter a PIN/pattern only when necessary, and evaluated its impact on efficiency and satisfaction. Both groups of participants, who prior to the study either locked or did not lock their phone, adopted our application and felt that unlocking their phone only when necessary was more efficient, did not annoy them and offered a reasonable level of security. Participants responded positively to the option of choosing when a PIN/pattern is required in different contexts. Therefore, we recommend that designers of smartphone locking mechanisms should consider ceding a reasonable level of control over security settings to users to increase adoption and convenience, while keeping smartphones reasonably secure.

Augmenting media with thermal stimulation

Thermal interfaces are a new area of research in HCI, with one of their main benefits being the potential to influence emotion. To date, studies investigating thermal feedback for affective interaction have either provided concepts and prototypes, or looked at the affective element of thermal stimuli in isolation. This research is the first to look in-depth at how thermal stimuli can be used to influence the perception of different media. We conducted two studies which looked at the effect of thermal stimuli on subjective emotional responses to media. In the first we presented visual information designed to evoke emotional responses in conjunction with different thermal stimuli. In the second we used different methods to present thermal stimuli in conjunction with music. Our results highlight the possibility of using thermal stimuli to create more affective interactions in a variety of media interaction scenarios.

Diversity, Assortment, Dissimilarity, Variety: A Study of Diversity Measures Using Low Level Features for Video Retrieval

In this paper we present a number of methods for re-ranking video search results in order to introduce diversity into the set of search results. The usefulness of these approaches is evaluated in comparison with similarity based measures, for the TRECVID 2007 collection and tasks [11]. For the MAP of the search results we find that some of our approaches perform as well as similarity based methods. We also find that some of these results can improve the P@N values for some of the lower N values. The most successful of these approaches was then implemented in an interactive search system for the TRECVID 2008 interactive search tasks. The responses from the users indicate that they find the more diverse search results extremely useful.

The effect of clothing on thermal feedback perception

Thermal feedback is a new area of research in HCI. To date, studies investigating thermal feedback for interaction have focused on virtual reality, abstract uses of thermal output or on use in highly controlled lab settings. This paper is one of the first to look at how environmental factors, in our case clothing, might affect user perception of thermal feedback and therefore usability of thermal feedback. We present a study into how well users perceive hot and cold stimuli on the hand, thigh and waist. Evaluations were carried out with cotton and nylon between the thermal stimulators and the skin. Results showed that the presence of clothing requires higher intensity thermal changes for detection but that these changes are more comfortable than direct stimulation on skin.