Manuel A. Pérez-Quiñones

Using Web search engines to find and refind information

To inform the design of next-generation Web search tools, researchers must better understand how users find, manage, and refind online information. Synthesizing results from one of their studies with related work, the authors propose a search engine use model based on prior task frequency and familiarity.

Building Multi-Platform User Interfaces with UIML

There has been a widespread emergence of computing devices in the past few years that go beyond the capabilities of traditional desktop computers. However , users want to use the same kinds of applications and access the same data and information on these appliances that they can access on their desktop computers. The user interfaces (UI) for these platforms go beyond the traditional interaction metaphors. It is a challenge to build UIs for these devices of differing capabilities that allow the end users to perform the same kinds of tasks. The User Interface Markup Language (UIML) is an XML-based language that allows the canonical description of UIs for different platforms. We describe the key aspects of our approach that makes UIML successful in building multi-platform UIs, namely the division in the representation of a UI, the use of a generic vocabulary, a process of transformations and an integrated development environment specifically designed for transformation-based UI development. Finally we describe the initial details of a multi-step usability engineering process for building multi-platform UI using UIML.

Digital memories in an era of ubiquitous computing and abundant storage

A lifetime of digital memories is possible but raises many social, as well as technological, questions.

Enhancing usability in CITIDEL: multimodal, multilingual, and interactive visualization interfaces

We describe four usability-enhancing interfaces to CITIDEL aimed at improving the user experience and supporting personalized information access by targeted communities. These comprise: a multimodal interaction facility with capability for out-of-turn input, interactive visualizations for exploratory analysis, a translation center exposing multilingual interfaces, as well as traditional usability enhancements. Pilot studies demonstrate the resulting improvements in quality, as measured across a number of metrics.

Evaluating two aspects of direct manipulation in advanced cockpits

Increasing use of automation in computer systems, such as advanced cockpits, presents special challenges in the design of user interfaces. The challenge is particularly difficult when automation is intermittent because the interface must support smooth transitions from automated to manual mode. A theory of direct manipulation predicts that this interface style will smooth the transition. Interfaces were designed to test the prediction and to evaluate two aspects of direct manipulation, semantic distance and engagement. Empirical results supported the theoretical prediction and also showed that direct engagement can have some adverse effects on another concurrent manual task. Generalizations of our results to other complex systems are presented.

NET GAINS IN POLITICAL PARTICIPATION: Secondary effects of Internet on community

Broad and diverse civic participation is essential to a democratic society. Studies of opinion leadership show that politically active citizens report that Internet information and communication helped increase civic involvement by enabling them to keep up more easily with news, interact with fellow citizens or engage in collective action. Yet information about less active citizens remains scant. Does the Internet influence the politically passive majority of citizens to become more involved in political talk or other forms of participation? Do they report that the Internet has been helpful in increasing their involvement in political issues, interactions with other citizens, or with local government? These kinds of impacts that follow the primary effect of gaining access to information are considered secondary effects of the Internet upon political participation (Sproull & Kiesler 1991). This article presents quantitative and qualitative findings from a case study of local political participation from the Blacksburg, Virginia region, within the context of a mature community computer network (the Blacksburg Electronic Village). Not only do politically active, but some politically passive citizens also report increased Internet use to communicate with other citizens and with fellow members of local groups about local or national issues. Further, in addition to politically active citizens, some politically passive citizens report that web logs (blogs) have fostered greater online exchange with other citizens through ad hoc political talk and knowledge sharing. These research findings help us to understand the secondary effects of the Internet on political participation in local communities.

Comparing effective and ineffective behaviors of student programmers

This paper reports on a quantitative evaluation of five years of data collected in the first three programming courses at Virginia Tech. The dataset involves a total of 89,879 assignment submissions by 1,101 different students. Assignment results were partitioned into two groups: scores above 80% (A/B) and scores below 80% (C/D/F). To investigate student behaviors that result in differing levels of achievement, all students who consistently received A/B scores and all students who consistently received C/D/F scores were removed from the dataset. A within-subjects comparison of the scores received by the remaining individuals was performed. Further, time and code-size data that is difficult to compare directly between different courses was normalized. This study revealed several significant results. When students received A/B scores, they started earlier and finished earlier than when the same students received C/D/F scores. They also wrote slightly more program code. They did not appear to spend any more time on their work, however. Approximately two-thirds of the A/B scores were received by individuals who started more than a day in advance of the deadline, while approximately two-thirds of the C/D/F scores were received by individuals who started on the last day or later. One possible explanation is that students who start earlier simply have more time to seek assistance when they get stuck.

Usability inspection of digital libraries: a case study

This paper reports a case study about lessons learned and usability issues encountered in a usability inspection of a digital library system called the Networked Computer Science Technical Reference Library (NCSTRL). Using a co-discovery technique with a team of three expert usability inspectors (the authors), we performed a usability inspection driven by a broad set of anticipated user tasks. We found many good design features in NCSTRL, but the primary result of a usability inspection is a list of usability problems as candidates for fixing. The resulting problems are organized by usability problem type and by system functionality, with emphasis on the details of problems specific to digital library functions. The resulting usability problem list was used to illustrate a cost/importance analysis technique that trades off importance to fix against cost to fix. The problems are sorted by the ratio of importance to cost, producing a priority ranking for resolution.

A collaborative model of feedback in human-computer interaction

Feedback plays an important role in human-computer interaction. It provides the user with evidence of closure, thus satisfying the communication expectations that users have when engaging in a dialogue. In this paper we present a model identifying five feedback states that must be communicated to the user to fulfill the communication expectations of a dialogue. The model is based on a linguistics theory of conversation, but is applied to a graphical user interface. An experiment is described in which we test users expectations and their behavior when those expectations are not met. The model subsumes some of the temporal requirements for feedback previously reported in the human-computer interaction literature.

Leveraging Social Networks to Embed Trust in Rideshare Programs

Traffic congestion, high gas price and inadequate public transportation are major challenges for any country, business or individual. The traditional approach to solving these problems has been to improve public transportation and use greener energy. These approaches require huge investment, research and time, and can only be carried out by governments or businesses. An alternative solution seeks to reduce the number of vehicles on the road based on ridesharing. Nevertheless, ridesharing is not a popular form of public transportation.In this paper, we summarize the results of a rideshare needs assessment survey conducted within the [university] community. The purpose behind this study was to understand commuter travel patterns, their needs and to identify their preferences for private vehicles and public transit for a variety of travel needs. Our results indicate that users are willing to increase participation in ridesharing programs if three core issues are addressed - trust, convenience and incentives.