Comparative Usability Study of Two Space Logistics Analysis Tools

Future space exploration missions and campaigns will require sophisticated tools to help plan and analyze logistics. To encourage their use, space logistics tools must be usable: a design concept encompassing terms such as efficiency, effectiveness, and satisfaction. This paper presents a usability study of two such tools: SpaceNet, a discrete event simulation tool and a comparable spreadsheet-based tool. The study follows a randomized orthogonal design having within-subjects evaluation of the two tools with 12 volunteer subjects (eight subjects with space backgrounds, four without). Each subject completed two sessions of testing, each with a 30-45 minute tutorial and a two-part space exploration scenario. The first part tests the creation a model to verify a simple uncrewed mission to lunar orbit. The second part tests the evaluation of an existing model to improve the effectiveness of a crewed mission to the lunar surface. The subjects completed a questionnaire after each session and a semi-structured interview following the second session. The study results indicate that the SpaceNet tool is more efficient for portions of the model creation task including modeling multi-burn transports and the spreadsheet tool is more effective for the model evaluation task. Qualitative evaluation indicates subjects liked the graphical nature and error-detection of the SpaceNet tool, but felt it took too long to edit information and appeared as a “black box.” Subjects liked the ability to view the entire model state within the spreadsheet tool, however were concerned with limited dynamic state feedback and underlying modeling assumptions. Future tools should combine the best features, including allowing modification of the entire model from a single interface, providing visibility of underlying logic, and integrated graphical and error-checking feedback.United States. Dept. of DefenseUnited States. Air Force Office of Scientific ResearchAmerican Society for Engineering Education. National Defense Science and Engineering Graduate Fellowship32 CFR 168aSamsung Fellowshi

Process-oriented evaluation of user interactions in integrated system analysis tools

When computer-based tools are used for analysis of complex systems, the design of user interactions and interfaces becomes an essential part of development that determines the overall quality. The objective of this study is to investigate the processes and results of user interactions with integrated analysis tools to synthesize design implications for future tool development. In this study, two space exploration logistics tools are compared in a controlled user experiment. Through a comparative usability analysis, this study evaluated user performance and perception to provide design implications for future integrated analysis tools. For a comprehensive evaluation, multiple methods were used for data collection, including observation, questionnaire and interview. In addition to a result-oriented performance analysis, a process-oriented approach was used for analyzing patterns in user behaviors and errors. Results are presented with reference to the related features embedded in the interfaces of the two tools. Based on the comparative results, synthesized design insights for hierarchical structure, model transparency, automation, and visualization and feedback are discussed for integrated analysis tools in general.American Society for Engineering Education. National Defense Science and Engineering Graduate Fellowshi

Oldest old’s travel mode choice and new mobility technology acceptance: case in America and China

IntroductionThe oldest olds (aged 85 and over) are the fastest-growing age segment. However, our understanding of their mobility is limited. To address this gap, we invited 19 U.S. and 30 Chinese “oldest old” to take part in focus groups and complete a mobility questionnaire. We focus on travel mode choice, which includes changes in travel modes, frequency of usage, and perceptions of comfort.MethodsOlder adults’ familiarity and acceptance of new mobility technologies (e.g., ridesharing, carsharing, and autonomous vehicles) were measured by questionnaire and focus group. Word clouds were also used to illustrate people’s reasons for choosing their primary mode of transportation.Results and discussionThe results show that both panels of older adults similarly feel some extent of travel limitations. But the responses among the two groups differ: 18 American participants chose “drive myself” as their primary option a decade ago, while 11 chose it now; no Chinese participants selected it either a decade ago or now. Both currently and 10 years ago, there was a significant difference in mode choice between participants in China and the United States. However, this gap has narrowed over the past decade. Participants in China have significantly changed their transportation preferences compared to 10 years ago, while participants in the US have remained nearly unchanged. American respondents consider “ease” as an important factor, while Chinese respondents pay more attention to “safety” and “no other option to get around” when making travel mode choices. Compared to Chinese participants, American participants were more comfortable with driving an autonomous vehicle. These differences may result from the various developmental stages and transportation policies of the two countries. This study supports the development of new mobility technologies for the oldest old to improve their quality of life

User-centered system design in an aging society : an integrated study on technology adoption

Thesis: Ph. D., Massachusetts Institute of Technology, Engineering Systems Division, 2014.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 229-240).The aging of the population is an important global phenomenon that is bringing changes and challenges to various areas of society. Technology has been explored as one way to cope with the complexities and uncertainties that are emerging with this demographic change. However, the responses from the potential user segment have been far from enthusiastic, suggesting that older adults' adoption of technology is not simply a matter of performance and price, but a complex issue that is affected by multiple factors. This dissertation explores the topic of older adults' technology adoption and use with an integrated framework that includes the perceptions, behaviors, and decisions of both the users and the producers. First, an exhaustive set of individual, technical, and social factors are identified and defined from a literature review and from user interviews with descriptions on these factors' importance and roles in the adoption and use process. Second, the results from a large-scale national survey are presented with a discussion of the empirical validity of the factors, as well as their relative importance and associations at three main decision stages of adoption and use -- purchase, initial use, and continued use. Finally, this dissertation presents a set of three cases developed from multiple sources of evidence on existing technology-enabled solutions for aging-in-place. The integrated framework described in this dissertation suggests the importance of considering population aging as a complex issue, as well as a new opportunity, that requires user-centered thinking from various players and stakeholders. Drawing on multiple methods of quantitative and qualitative data collection and analysis, the results underscore the importance and roles of different adoption factors during the design, development, and delivery of technology, as well as in older adults' decisions around adoption and use. This dissertation finds that the various requirements, expectations, and values of older adults are closely related and collectively affect their decisions and behaviors around technology. Finally, a set of implications for research and practice are presented around the need for the continuous involvement of older adults throughout design, development, and delivery of technologies for a changing population.by Chaiwoo Lee.Ph. D

Considering Self-Report in the Interpretation of Objective Performance Data in the Comparison of HMI Systems

Driver interaction with two production voice-command interfaces representing differing user interface design approaches were compared under onroad highway driving conditions. A sample of 80 drivers was randomly assigned to drive each vehicle (40 per vehicle). During voice-based phone contact calling and destination address entry, participants in one vehicle showed, on average, statistically significant “better” performance in terms of task completion time, mean glance duration, total off-road glance time, and total number of glances. However, these objective measures do not fully characterize the overall experience of participants. An analysis of error rates and subjective report of attitudes, effects on driving behavior, and behavioral intentions relative to their exposure to the two systems provided important, complementary and sometimes contrasting data about the relative advantages of each implementation

Consumer Comfort with Vehicle Automation: Changes Over Time

Higher levels of vehicle automation are forecast as a potential mobility solution for many, but understanding consumer comfort and acceptance of selfdriving technologies remains an open question. Results from a series of surveys over three years showed a slight increase in the percentage of people comfortable with full self-driving automation in 2018, following a drop from 2016 to 2017. The recovery in comfort with higher levels of automation was most pronounced among younger adults between ages 25 and 44. However, the percentage of people only comfortable with no automation or features that activate only in certain situations such as in an emergency also increased in the past year, indicating a polarizing trend. Results from the survey also showed that acceptance of self-driving vehicles is conditional on people’s ability to drive as well as having assurance regarding the safety of the technology. Responses also point to a possible misunderstanding among the public regarding the definition and availability of full self-driving technology, indicating a need for improved messaging and consumer education