D. Scott McCrickard

Notification and awareness: synchronizing task-oriented collaborative activity

People working collaboratively must establish and maintain awareness of one anothers intentions, actions and results. Notification systems typically support awareness of the presence, tasks and actions of collaborators, but they do not adequately support awareness of persistent and complex activities. We analysed awareness breakdowns in use of our Virtual School system--stemming from problems related to the collaborative situation, group, task and tool support--to motivate the concept of activity awareness. Activity awareness builds on prior conceptions of social and action awareness, but emphasizes the importance of activity context factors like planning and coordination. This work suggests design strategies for notification systems to better support collaborative activity.

A model for notification systems evaluation—assessing user goals for multitasking activity

Addressing the need to tailor usability evaluation methods (UEMs) and promote effective reuse of HCI knowledge for computing activities undertaken in divided-attention situations, we present the foundations of a unifying model that can guide evaluation efforts for notification systems. Often implemented as ubiquitous systems or within a small portion of the traditional desktop, notification systems typically deliver information of interest in a parallel, multitasking approach, extraneous or supplemental to a users attention priority. Such systems represent a difficult challenge to evaluate meaningfully. We introduce a design model of user goals based on blends of three critical parameters---interruption, reaction, and comprehension. Categorization possibilities form a logical, descriptive design space for notification systems, rooted in human information processing theory. This model allows conceptualization of distinct action models for at least eight classes of notification systems, which we describe and analyze with a human information processing model. System classification regions immediately suggest useful empirical and analytical evaluation metrics from related literature. We present a case study that demonstrates how these techniques can assist an evaluator in adapting traditional UEMs for notification and other multitasking systems. We explain why using the design model categorization scheme enabled us to generate evaluation results that are more relevant for the system redesign than the results of the original exploration done by the systems designers.

Attuning notification design to user goals and attention costs

Why is the attentive user interface paradigm important for human-computer interaction? The human attention system is so sensitive to various methods of notification that traditional design involves too much compromise and guesswork.

Establishing tradeoffs that leverage attention for utility: empirically evaluating information display in notification systems

Designing and evaluating notification systems represents an emerging challenge in the study of human-computer interaction. Users rely on notification systems to present potentially interruptive information in an efficient and effective manner to enable appropriate reaction and comprehension. Little is known about the effects of these systems on ongoing computer tasks. As the research community strives to understand information design suitable for opposing usage goals, few existing efforts lend themselves to extensibility.However, three often conflicting design objectives are interruption to primary tasks, reaction to specific notifications, and comprehension of information over time. Based on these competing parameters, we propose a unifying research theme for the field that defines success in notification systems design as achieving the desirable balance between attention and utility. This paradigm distinguishes notification systems research from traditional HCI by centering on the limitations of the human attention system.In a series of experiments that demonstrate this research approach and investigate use of animated text in secondary displays, we describe two empirical investigations focused on the three critical parameters during a browsing task. The first experiment compares tickering, blasting, and fading text, finding that tickering text is best for supporting deeper comprehension, fading best facilitates reaction, and, compared to the control condition, none of the animated displays are interruptive to the browsing task. The second experiment investigates fading and tickering animation in greater detail with similar tasks--at two different speeds and sizes. Here, we found smaller displays allowed better reaction but were more interruptive, while slower displays provides increased comprehension. Overall, the slow fade appears to be the best secondary display animation type tested. Focusing research and user studies within this field on critical parameters such as interruption, reaction, and comprehension will increase cohesion among design and evaluation efforts for notification systems.

Introduction: design and evaluation of notification user interfaces

Notification systems attempt to deliver current, important information to the computer screen in an efficient and effective manner. All notification systems require that the user attends to them to at least some degree if they are to succeed. Examples of notification systems include instant messaging systems, system and user status updates, email alerts and news and stock tickers. The benefits of notification systems are numerous, including rapid availability of important information, access to nearly instantaneous communication and heightened awareness of the availability of personal contacts. While the popularity of these systems has skyrocketed in recent years, the effects of incoming notifications on ongoing computing tasks have been relatively unexplored. The investigation of the costs, benefits and the optimal display of instant messages and all notifications in the context of desktop or mobile computing tasks falls in the general arena of psychological research on alerting and disruptions, but also requires research contributions from design, computer science and information visualization. To date, much of the psychological research on interruption leverages theoretical task constructions. In this special issue, we focus on the nature of interruptions such as messaging while computing and how to optimize the user experience.

Classroom BRIDGE: using collaborative public and desktop timelines to support activity awareness

Classroom BRIDGE supports activity awareness by facilitating planning and goal revision in collaborative, project-based middle school science. It integrates large-screen and desktop views of project times to support incidental creation of awareness information through routine document transactions, integrated presentation of awareness information as part of workspace views, and public access to subgroup activity. It demonstrates and develops an object replication approach to integrating synchronous and asynchronous distributed work for a platform incorporating both desktop and large-screen devices. This paper describes an implementation of these concepts with preliminary evaluation data, using timeline-based user interfaces.

Effective features of algorithm visualizations

Many algorithm visualizations have been created, but little is known about which features are most important to their success. We believe that pedagogically useful visualizations exhibit certain features that hold across a wide range of visualization styles and content. We began our efforts to identify these features with a review that attempted to identify an initial set of candidates. We then ran two experiments that attempted to identify the effectiveness for a subset of features from the list. We identified a small number of features for algorithm visualizations that seem to have a significant impact on their pedagogical effectiveness, and found that several others appear to have little impact. The single most important feature studied is the ability to directly control the pace of the visualization. An algorithm visualization having a minimum of distracting features, and which focuses on the logical steps of an algorithm, appears to be best for procedural understanding of the algorithm. Providing a good example for the visualization to operate on proved significantly more effective than letting students construct their own data sets. Finally, a pseudocode display, a series of questions to guide exploration of the algorithm, or the ability to back up within the visualization did not show a significant effect on learning.

Examining the Foundations of Agile Usability with eXtreme Scenario-Based Design

The increasing use of agile methods to develop UI-intensive systems has led to a need to find ways of integrating usability into agile teams—reconciling the convergence and divergent points between the two areas. Agile usability researchers at Virginia Tech have partnered with Meridium, Inc. to develop and implement an integrated approach known as eXtreme Scenario-based Design (XSBD). Based on an analysis of core values and principles of both areas, and work from other agile usability researchers we identified four requirements that need to be met for an integrated approach to work effectively. We report on the results of using XSBD to develop a product at Meridium, summarizing how it addresses those requirements and draw conclusions about the effectiveness of the approach—making connections back to core principles of agile usability.

Design, science, and engineering topics?: teaching HCI with a unified method

Reacting to challenges that have been observed in human-computer interaction (HCI) education, as well as the multidisciplinary design, science, and engineering underpinnings, we investigate a pedagogical approach based on case methods. Our study of various case method techniques in an undergraduate HCI class provides insights into challenges that can be expected in the employment of case methods, student learning outcomes, and considerations for HCI curriculum planning. In general, case methods show great promise with a wide variety of topics, and we present broad recommendations for future work that will improve integration of HCI professional practice, research, and education.

Unpacking critical parameters for interface design: evaluating notification systems with the IRC framework

We elaborate a proposal for capturing, extending, and reusing design knowledge gleaned through usability testing. The proposal is specifically targeted to address interface design for notification systems, but its themes can be generalized to any constrained and well-defined genre of interactive system design. We reiterate arguments for and against using critical parameters to characterize user goals and usability artifacts. Responding to residual arguments, we suggest that clear advantages for research cohesion, design knowledge reuse, and HCI education are possible if several challenges are overcome. As a first step, we recommend a slight variation to the concept of a critical parameter, which would allow both abstract and concrete knowledge representation. With this concept, we demonstrate a feasible approach by introducing equations that elaborate and allow evolution of notification system critical parameters, which is made operational with a variety of usability evaluation instruments. A case study illustrates how one general instrument allowed system designs to be meaningfully compared and resulted in valuable inferences for interface reengineering. Broad implications and conclusions about this approach will be of interest to others concerned with using critical parameters in interface design, development of notification systems interfaces, or approaches to design rationale and knowledge reuse.