Office workers often lead sedentary lifestyles, a lifestyle responsible for higher risks of cardiovascular disease, stroke, diabetes and premature mortality. Improvements towards a more active lifestyle reduce cardiovascular risks and thus changing the sedentary lifestyle might prevent chronic illness. The Recurring Sedentary Period Detection (RSPD) algorithm described in this paper was designed to identify recurring sedentary periods using data from an activity tracker, summarise the sedentary periods and pinpoint notification times at which the user should be motivated to get some movement. The outcome of the RSPD algorithm was validated using data from a 10-week period of one typical office worker. Our results show that the RSPD algorithm could correctly identify the recurring sedentary periods, compute fitting daily summaries and pinpoint the notification times correctly. With minor differences, the RSPD algorithm was successfully implemented in the healthyMe smartphone applicati

Informal caregivers of people with cognitive impairment are often concerned about the health and wellbeing of their loved ones, leading to frequent care-related visits, check-ups, and conversations. Results from focus groups we held in daily care showed a strong need for support in terms of information about the health and wellbeing of the person with cognitive impairment (PwCI). The health monitoring application developed in this study, called HELMA, aims to offer a solution by monitoring the health and wellbeing of the PwCI in the long term and informing the informal caregivers. HELMA is an eHealth application that uses short frequent online monitoring questions to provide informal caregivers with information about the following health and wellbeing domains: physical; mental; social; and environmental. The next step is to evaluate HELMA on a large scale with end-users in daily practice.

We study the effectiveness of stereoscopy and smooth motion as 3D cues for medical interpretation of vascular structures as obtained by 3D medical imaging techniques. We designed a user study where the user has to follow a path in a mazelike solid shaded 3D structure. The user controls rotation of the model. We measure user performance in terms of time taken and error rate. The experiment was executed with 32 (medical and non-medical) users. The results show that motion cue is more important than stereoscopy, and that stereoscopy has no added value when motion is already present, which is not consistent with previous experiments.

Visual search is a task that is performed in various application areas. Search can be aided by an automatic warning system, which highlights the sections that may contain targets and require the user's attention. The effect of imperfect automatic warnings on overall performance ultimately depends on the interplay between the user and the automatic warning system. While various user studies exist, the different studies differ in several experimental variables including the nature of the visualisation itself. Studies in the medical area remain relatively rare, even though there is a growing interest in medical screening systems. We describe an experiment where users had to perform a visual search on a vascular structure, traversing a particular vessel linearly in search of possible errors made in an automatic segmentation. We find that only the case in which the warning system generates only false positives improves user time and error performance. We discuss this finding in relation to the findings of other studies.

Abstract One of the basic topics of question answering (QA) dialogue systems is how follow-up questions should be interpreted by a QA system. In this paper, we shall discuss our experience with the IMIX and Ritel systems, for both of which a follow-up question handling scheme has been developed, and corpora have been collected. These two systems are each other's opposites in many respects: IMIX is multimodal, non-factoid, black-box QA, while Ritel is speech, factoid, keyword-based QA. Nevertheless, we will show that they are quite comparable, and that it is fruitful to examine the similarities and differences. We shall look at how the systems are composed, and how real, non-expert, users interact with the systems. We shall also provide comparisons with systems from the literature where possible, and indicate where open issues lie and in what areas existing systems may be improved. We conclude that most systems have a common architecture with a set of common subtasks, in particular detecting follow-up questions and finding referents for them. We characterise these tasks using the typical techniques used for performing them, and data from our corpora. We also identify a special type of follow-up question, the discourse question, which is asked when the user is trying to understand an answer, and propose some basic methods for handling it.

The Ritel system aims to provide open-domain question answering to casual users by means of a telephone dialogue. This implies some unique challenges, such as very fast overall performance and large-vocabulary speech recognition. Speech QA is an error-prone process, but errors or problems that occur may be resolved with help of user feedback, as part of a natural dialogue. This paper reports on a pilot study conducted with the latest version of Ritel, which includes search term confirmation and improved follow-up question handling, as well as various improvements on the other system components. We collected a small dialogue corpus with the new system, which we use to evaluate and discuss it. Index Terms: speech QA, dialogue systems, confirmation. 1. The Ritel platform

This paper gives an overview of issues related to extending simple question answering (QA) with dialogue capabilities, when designing a multimodal interactive information extraction system for a large, though restricted, domain. We present the way in which these issues are approached in the IMIX program. The IMIX demonstrator system, under development in this program, may be considered the most difficult case of QA, answering non-factoid questions in a large domain, and accepting speech input as well. We describe our approach to the addition of dialogue capabilities to this system. We will look at QA from a dialogue system perspective and from a HCI perspective, and consider the consequences of our choice of interaction metaphor, the `information search assistant'.