This article addresses factors that will influence future human spaceflight missions. A fictional Mars expedition vignette highlights how a future Mars expedition may be tied to societal challenges and research priorities on Earth. Historical aspects of the Apollo era are used to emphasize sociotechnical factors that can influence goals, priorities, and larger societal effects of spaceflight. Current cultural and technology factors will strongly affect spaceflight in the year 2035. However, sociotechnical disruptions influence the robustness of mission planning efforts. The goal is to recognize and prepare for a range of possible futures affecting spaceflight mission scenarios.
Objective: This article describes a series of studies conducted to examine factors affecting user perceptions, responses, and tolerance for network-based computer delays affecting distributed human-computer-network interaction (HCNI) tasks. Background: HCNI tasks, even with increasing computing and network bandwidth capabilities, are still affected by human perceptions of delay and appropriate waiting times for information flow latencies. Method: Conducted were 6 laboratory studies with university participants in China (Preliminary Experiments 1 through 3) and the United States (Experiments 4 through 6) to examine users' perceptions of elapsed time, effect of perceived network task performance partners on delay tolerance, and expectations of appropriate delays based on task, situation, and network conditions. Results: Results across the six experiments indicate that users' delay tolerance and estimated delay were affected by multiple task and expectation factors, including task complexity and importance, situation urgency and time availability, file size, and network bandwidth capacity. Results also suggest a range of user strategies for incorporating delay tolerance in task planning and performance. Conclusion: HCNI user experience is influenced by combinations of task requirements, constraints, and understandings of system performance; tolerance is a nonlinear function of time constraint ratios or decay. Application: Appropriate user interface tools providing delay feedback information can help modify user expectations and delay tolerance. These tools are especially valuable when delay conditions exceed a few seconds or when task constraints and system demands are high. Interface designs for HCNI tasks should consider assistant-style presentations of delay feedback, information freshness, and network characteristics. Assistants should also gather awareness of user time constraints.
Many systems involving multiple remote sensors or machines require a single operator to control more than one device simultaneously. Interface design issues for such systems can be formidable because the inherent complexity of multiple-platform control creates significant opportunities for operator confusion and overload. An exploratory study was conducted to examine some of these issues using a simulated industrial security task. The experiment manipulated the type of remote sensor (fixed-site or mobile), the number of displays that had to be monitored, and two types of event complexity (number of targets and redundancy of target images) using response time as the dependent measure. Results showed that significant performance penalties may be encountered in multiple-platform control and that these penalties accumulate at seemingly low levels of complexity.
This paper summarizes results of a user evaluation survey of computer-based telephone messaging ("voice mail") technologies. A mail survey of the population of voice mail users in state government agencies (approximately 3000 users) yielded 1072 user responses. Survey analyses tested hypotheses regarding how voice mail evaluations are influenced by user characteristics, system use and experience, task and situation factors, and differences in organizational context and operations. Highlights of the results include findings relating both endogenous (age and gender) and exogenous (reported length of experience and average weekly use) user characteristics to ratings of the voice mail interface. Participating organizations reported mean differences in ratings of the interface and situation-based voice mail appropriateness. The findings emphasize the importance of a systems approach to integrate user-centered design and functional, situational, and organizational contexts in order to enhance the success of implementing voice mail and other telecommunications technologies.
