Paulo J. Santos

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Researchers in human-computer interactions know that software can easily be instrumented to create a trace of user events2 in the interface (which we call a log file) for later analysis. Using these data for studying usability or other HCI questions is certainly attractive. • The data are cheap – data gathering is totally automated. • The data are gathered(More)
This paper presents a simple but very powerful technique to support user interface evaluation along with a prototype open environment — I-Observe, the Interface OBServation, Evaluation, Recording, and Visualization Environment. I-Observe's technique requires recording user interface sessions in multiple modalities, both as a trace of interesting events and(More)
This paper describes an algorithm to detect user's mental chunks by analysis of pause lengths in goal-directed human-computer interaction. Identifying and characterizing users' chunks can help in gauging the users' level of expertise. The algorithm described in this paper works with information collected by an automatic logging mechanism. Therefore, it is(More)
The purpose of the present study was to analyze longitudinal changes in 3,000 m running performance and the relationship with selected physiological parameters. Eighteen well-trained male middle-distance runners were measured six times (x3 per year) throughout two consecutive competitive seasons. The following parameters were measured on each occasion:(More)
OBJECTIVE To analyze the variability and longitudinal stress-related changes in ulnar variance (UV) in a group of immature artistic gymnasts. The relationship between UV and a group of biological and training variables was also investigated. DESIGN Prospective cohort study. SETTING Portuguese Federation of Gymnastics. PARTICIPANTS Twenty-five(More)
This paper presents a simple but very powerful technique to support user interface evaluation along with a prototype open environment — I-Observe, the Interface OBServation, Evaluation, Recording, and Visualization Environment — which supports a preliminary implementation of this technique. This technique operates by recording user interface sessions in(More)
This paper presents a simple but very powerful technique to support user interface evaluation, along with a prototype implementation of this technique. This technique provides tools to allow the user interface evaluator to combine event streams and video recording, analyzing the event stream to search for patterns of interesting or important user actions,(More)
Designers of interactive systems often work in environments that am continuously changing. External, uncontrollable change is rapidly becoming a daily impedim~t in many designers’ lives. In this age of rapid technologml progression and heightened competition, systems designers must be able to prepare for, cope with, and even pdbrm better because of(More)
According to the self-psychology of Heinz Kohut, development of a healthy narcissism that is reflected in a secure sense of self, permits individuals to set and pursue meaningful life goals and maintain a sense of well-being, particularly in periods of transition and change. Based on this perspective, the primary purpose of this study was to assess the(More)