Projekte

Application programming interfaces (APIs) are the interfaces to existing code structures, such as widgets, frameworks, or toolkits. Therefore, they very much do have an impact on the quality of the resulting system. So, ensuring that developers can make the most out of them is an important challenge. However standard usability evaluation methods as known from HCI have limitations in grasping the interaction between developer and API as most IDEs (essentially the GUI) capture only part of it. In this paper we present the Concept Map method to study the usability of an API over time. This allows us to elicit the mental model of a programmer when using an API and thereby identify usability issues and learning barriers and their development over time.

In this paper we present Pocket Bee, a multi-modal diary tool that allows researchers to remotely collect rich and in-depth data in the field. Based on the Android smart phone platform, we especially focused on an easy to use user interface. We introduce the notion of core questions that serve as cognitive triggers for pre-defined events. Multiple modalities allow participants to compose notes in the most appropriate and convenient way. Instant network synchronization allows researchers to view and analyze the data on-the-fly while also being able to create new tasks or questionnaires during an ongoing study. These can also be linked to certain trigger events, such as time and date. Thereby, Pocket Bee supports diary and Experience Sampling (ESM) studies. The system was developed in a user-centered design process and its potential value is described in a scenario of use illustrating an upcoming study.

Application programming interfaces (APIs) are the interfaces to existing code structures, such as widgets, frameworks, or toolkits. Therefore, they very much do have an impact on the quality of the resulting system. So ensuring that developers can make the most out of them is an important challenge. However standard usability evaluation methods as known from HCI have limitations in grasping the interaction between developer and API -- the GUI, which makes this interaction obvious, is missing. In this paper we present a longitudinal approach using concept maps and a question diary to make this interaction visible and study the usability of an API over time.

While touch interaction with tabletops is now widely accepted as a very natural and intuitive form of input, only little research has been carried out to understand whether and how it might interfere with our natural ways of gestural communication. This poster presents a study that aims at understanding the importance of touching physical and virtual artifacts during discussion or collaboration around a table. Furthermore, it focuses on how users compensate for conflicts between non-interactivity and interactivity created by unintended touch interaction when using a multi-touch enabled tabletop. In our study, we asked participants to explain illustrations of technical or physical mechanisms, such as the workings of an airplane wing. We observed whether and how they used gestures to do so on a touch sensitive Microsoft Surface tabletop and on a sheet of paper. Our results suggest that touching is an essential part of such an activity and that the compensation strategies people adapt to avoid conflicts may reduce precision of communication and increase the physical strain on the user.

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dc.contributor.author: Specht, Marcus; Söter, Andrea; Gerken, Jens; Jetter, Hans-Christian; Bohrer, Lorenz; Reiterer, Harald

Während klassische Experimente oder Usability Tests oft nur eine Momentaufnahme darstellen, ermöglichen es Längsschnittstudien auch Veränderungen zu beobachten und zu einem ökologisch valideren Gesamtbild der Gebrauchstauglichkeit zu gelangen. Bislang werden derartige Verfahren aber noch sehr selten in der Mensch-Computer Interaktion eingesetzt. In diesem Beitrag wird auf Basis einer umfangreichen Literaturanalyse eine Taxonomie vorgestellt, die einen Überblick über die vielfältigen Möglichkeiten von Längsschnittstudien ermöglicht. Hierdurch kann sowohl der wissenschaftliche Diskurs verbessert werden, um die bekannten Ansätze weiter zu verbessern, als auch dem praktischen Anwender Hilfestellung in Planung und Durchführung einer Längsschnittstudie gegeben werden.

In this paper we present our experiences with longitudinal study designs for pointing device evaluation. In this domain, analyzing learning is currently the main reason for applying longitudinal designs. We will shortly discuss related research questions and outline two case studies in which we used different approaches to address this issue.

In this paper we present our experiences with longitudinal study designs for input device evaluation. In this domain, analyzing learning is currently the main reason for applying longitudinal designs. We will shortly discuss related research questions and outline two case studies in which we used different approaches to address this issue. Finally, we will point out future research tasks in the context of longitudinal evaluation methods.

Der Einsatz von Werkzeugen aus dem Bereich der Informationsvisualisierung im privaten Alltag, beispielsweise beim Stöbern in digitalen Bibliotheken wie einer Filmdatenbank, stellt Entwickler vor neue Herausforderungen bezüglich des Interaktionsdesigns muss dieses doch den deutlich höheren Anforderungen der zumeist unerfahrenen Nutzer hinsichtlich der Gebrauchstauglichkeit genügen. Ein möglicher Lösungsansatz könnte hierbei in dem kombinierten Einsatz möglichst einfacher Werkzeuge, die auf einem einheitlichen Interaktionsdesign basieren, liegen. Dieser Beitrag führt die Arbeit aus (Reiterer et al. 2005) fort und zeigt am Beispiel eines Punktdiagramms, dem HyperScatter auf, wie die dort vorgestellte Modellierung des Informationsraums in Kombination mit Zoomtechniken auf andere Werkzeuge übertragbar ist und hierdurch das Ziel eines einheitlichen Interaktionsdesigns erreicht wird. Weiterhin wurde der HyperScatter in einer neuartigen zweiwöchigen Längsschnitt-Evaluationsstudie auf seine Gebrauchstauglichkeit hin überprüft sowie auf seine Fähigkeit, als alleinstehendes Werkzeug den Benutzer in seiner Informationssuche zu unterstützen.

In this paper we argue for a combined approach of logging analysis and interview techniques to evaluate the usability of web distributed applications. Logging analysis has proven as an efficient and effective method to investigate websites usability. However it seems insufficient for more complex applications. We outline a case study of a library search system, in which users' information seeking behavior is investigated with both the analysis of log files and qualitative interviews with real users. We argue that such an approach should provide a more accurate usability assessment of the system, especially when users' performance in a long-run is investigated.

In Human-Computer studies and visual analytics, the majority of the evaluation methods applied, collect data at a single point in time, in form of cross-sectional data. In several studies numerous visualization tools were evaluated in controlled experiments. Although the experiments discovered valuable findings, certain drawbacks of the research method were expressed. The time constraints of one-time experiments reduce the amount of training which can be given to the participants.
Furthermore, when the studies tried to measure the insight derived from the visualization tools the time constraints didn't allow observing how these insights develop over time or their interdependency. Further problems of cross-sectional studies are well known, like the selection of appropriate tasks, the mostly extrinsic motivation of the participants, the influence of a laboratory environment compared to a realistic work setting and whether a visualization tool does meet the work requirements in the long run. In this position paper we argue for applying longitudinal research methods in human-computer studies as an extension to cross-sectional studies and present a first approach towards a methodological research framework. We suggest a set of research questions and performance measures that would be benefical for extending cross-sectional studies with longitudinal ones. We also describe in two case studies, in which only cross-sectional research methods were used, how they can improved by longitudinal methods.