Strategies to design for dynamic usability

Since usability is a property of the interaction between a product, a user and the task that he or she is trying to complete [6], a product’s usability can vary when it is used in varying use situations. We define this as dynamic usability. This study is aimed at exploring how practitioners currently deal with dynamic usability. From a retrospective case study research of three design projects different principles and strategies were formulated for dealing with dynamic use situations. In this paper we present solution principles that are applied to accommodate products to dynamic use situations and we discuss two design process issues with regard to dynamic usability, namely the information sources that are used to get insight in the use situations and the means by which designers try to get insight in the consequence of their design decisions with regard to future use situation

Participatory Scenario Generation: Communicating Usability Issues in Product Design through User Involvement in Scenario Generation\ud

Scenarios have proven to be a valuable tool in evaluating and communicating usability issues in consumer product design. Scenarios are explicit descriptions of hypothetical use situations. Realistic scenarios can serve as a valuable frame of reference to evaluate design solutions with regard to usability. To be able to achieve this required level of realism, involving users in scenario generation is essential. In this presentation we discuss how and where users can be involved in a scenario based product design process by means of examples of design projects that were executed by master students Industrial Design Engineering of the University of Twente. \ud \ud We distinguish direct and indirect scenario generation. In direct scenario generation the user is actively involved in a participatory scenario generation session: the scenarios are created together with users. Indirect scenario generation is an approach in which scenarios are created by designers based on common analysis techniques like observations and interviews. These scenarios are then offered to users for confirmation. Both types of user involvement in scenario generation can be aimed at either current use scenarios which describe the current situation or future use scenarios which include a new product design. \ud \ud The examples show that all strategies can be applied successfully to create realistic scenarios. Which strategy to choose depends among others upon risks and privacy issues, occurrence of infrequent events and availability of users. Furthermore, the variety of approaches shows that there is still a lot to explore with regard to benefits and limitations of the many techniques that can be applied in generating scenarios for consumer product design. We hope to contribute to this field by means of the research in our group and the work of students in the SBPD course\u

Tracing the Scenarios in Scenario-Based Product Design: a study to support scenario generation

Scenario-based design originates from the human-computer interaction and\ud software engineering disciplines, and continues to be adapted for product development. Product development differs from software development in the former’s more varied context of use, broader characteristics of users and more tangible solutions. The possible use of scenarios in product design is therefore broader and more challenging. Existing design methods that involve scenarios can be employed in many different stages of the product design process. However, there is no proficient overview that discusses a\ud scenario-based product design process in its full extent. The purposes of creating scenarios and the evolution of scenarios from their original design data are often not obvious, although the results from using scenarios are clearly visible. Therefore, this paper proposes to classify possible scenario uses with their purpose, characteristics and supporting design methods. The classification makes explicit different types of scenarios and their relation to one another. Furthermore, novel scenario uses can be referred or added to the classification to develop it in parallel with the scenario-based design\ud practice. Eventually, a scenario-based product design process could take inspiration for creating scenarios from the classification because it provides detailed characteristics of the scenario

The Design of a new NICU Patient Area: Combining Design for Usability and Design for Emotion

In the design of medical products both usability and emotional experience are important to be considered. Usability can enhance the work situation of medical staff and ensure patient safety. Emotion related product aspects, on the other hand, influence the recovery pace of patients as well as the work satisfaction of staff. For an optimal medical design both aspects should receive well-balanced attention during the design process. Usability and emotional experience are currently related in literature. However, about the relation between these two aspects in practical design projects little information is available. Therefore we will discuss the exploration of the practical relation between Design for Usability and Design for Emotion in a design process. We explored the relation during concurrent application of both design approaches to the design of a patient area for a Neonatal Intensive Care Unit (NICU). Our aim was not to develop a new design method, but to explore in practice how both design approaches could be addressed concurrently. This paper describes the applied design approach, its strength and weaknesses as well as the design results. Overall, the NICU design case has proven that the concurrent application of Design for Emotion and Design for Usability is feasible in practice and results in a satisfactory design. Keywords: Usability; Design For Emotion; Medical Appliance; Participatory Design; Case Study</p

Microjets in the penumbra of a sunspot

Penumbral Microjets (PMJs) are short-lived jets found in the penumbra of sunspots, first observed in wide-band Ca H-line observations as localized brightenings, and are thought to be caused by magnetic reconnection. Earlier work on PMJs has been focused on smaller samples of by-eye selected events and case studies. It is our goal to present an automated study of a large sample of PMJs to place the basic statistics of PMJs on a sure footing and to study the PMJ Ca II 8542 Angstrom spectral profile in detail. High spatial resolution and spectrally well-sampled observations in the Ca II 8542 Angstrom line obtained from the Swedish 1-m Solar Telescope (SST) are reduced by a Principle Component Analysis and subsequently used in the automated detection of PMJs using the simple learning algorithm k-Nearest Neighbour. PMJ detections were verified with co-temporal Ca H-line observations. A total of 453 tracked PMJ events were found, or 4253 PMJs detections tallied over all timeframes and a detection rate of 21 events per timestep. From these, an average length, width and lifetime of 640 km, 210 km and 90 s were obtained. The average PMJ Ca II 8542 Angstrom line profile is characterized by enhanced inner wings, often in the form of one or two distinct peaks, and a brighter line core as compared to the quiet Sun average. Average blue and red peak positions were determined at -10.4 km/s and +10.2 km/s offsets from the Ca II 8542 Angstrom line core. We found several clusters of PMJ hotspots within the sunspot penumbra, where PMJ events occur in the same general area repeatedly over time. Our results indicate smaller average PMJs sizes and longer lifetimes compared to previously published values, but with statistics still in the same orders of magnitude. The investigation and analysis of the PMJ line profiles strengthen the proposed heating of PMJs to transition region temperatures.Comment: Figures 1, 2, 3, 4 and 11 exhibited artifacts in some pdf-readers, and have been replotted with new graphical settings to remedy this. Apart from slight changes in sizing and fonts, the figures are the same. The arXiv abstract has had tex-syntax removed for better readabilit

Penumbral micro-jets at high spatial and temporal resolution

Sunspot observations in chromospheric spectral lines have revealed the existence of short-lived linear bright transients, commonly referred to as penumbral micro-jets (PMJs). Details on the origin and physical nature of PMJs are to large extend still unkown. We aim to characterize the dynamical nature of PMJs to provide guidance for future modelling efforts. We analyze high spatial (0.1 arcsec) and temporal resolution (1 s) Ca II H filtergram (0.1 nm bandwidth) observations of a sunspot obtained on two consecutive days with the Swedish 1-m Solar Telescope. We find that PMJs appear to be the rapid brightening of an already existing (faint) fibril. The rapid brightening is the fast increase (typically less than 10 s) in intensity over significant length (several 100s of km) of the existing fibril. For most PMJs, we cannot identify a clear root or source from where the brightening appears to originate. After the fast onset, about half of the PMJs have a top that is moving with an apparent velocity between 5 and 14 km/s, most of them upwards. For the other PMJs, there is no significant motion of the top. For about a third of the PMJs we observe a splitting into two parallel and co-evolving linear features during the later phases of the lifetime of the PMJ. We conclude that mass flows can play only limited role in the onset phase of PMJs and that it is more likely that we see the effect of a fast heating front.Comment: Accepted for publication in Astronomy & Astrophysics. Movies are available at http://folk.uio.no/rouppe/pmj_highcadence