R-3 Repository :: Browsing by Author "Byrne, Michael D."

Browsing by Author "Byrne, Michael D."

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A Computational Model of Jetliner Taxiing
(2012) Zemla, Jeffrey C.; Byrne, Michael D.
The Next Generation Air Transportation System (NextGen) is transforming the way planes move on the ground as well as in the sky. Some of the proposed changes, such as automated scheduling algorithms to generate taxi clearances and speed-based taxi clearances, require thorough testing to ensure safety and reliability. Cognitive modeling is able to uniquely address these issues in a compromise between costly human-in-the-loop simulations and deterministic computer simulations. In this thesis, I present an ACT-R cognitive model to emulate pilot taxiing behavior in a dynamic environment, in order to predict human behavior in novel situations imposed by NextGen constraints. The model is validated by comparing taxi routes generated by the model to routes driven by real pilots while on the job.
A Computational Model of Routine Procedural Memory
(Rice University, 2009) Tamborello, Franklin Patrick, II; Byrne, Michael D.
Cooper and Shallice (2000) implemented a computational version of the Norman and Shallice’s (1986) Contention Scheduling Model (CSM). The CSM is a hierarchically organized network of action schemas and goals. Botvinick and Plaut (2004) instead took a connectionist approach to modeling routine procedural behavior. They argued in favor of holistic, distributed representation of learned step co-occurrence associations. Two experiments found that people can adapt routine procedural behavior to changing circumstances quite readily and that other factors besides statistical co-occurrence can have influence on action selection. A CSM-inspired ACT-R model of the two experiments is the first to postdict differential error rates across multiple between-subjects conditions and trial types. Results from the behavioral and modeling studies favor a CSM-like theory of human routine procedural memory that uses discrete, hierarchically-organized goal and action representations that are adaptable to new but similar procedures.
A computational model of routine procedural memory
(2009) Tamborello, Franklin Patrick, II; Byrne, Michael D.; Kortum, Philip T.; Lane, David M.; Autry, Lynette S.; Dannemiller, James L.; Napier, Albert H.
Cooper and Shallice (2000) implemented a computational version of the Norman and Shallice's (1986) Contention Scheduling Model (CSM). The CSM is a hierarchically organized network of action schemas and goals. Botvinick and Plaut (2004) instead took a connectionist approach to modeling routine procedural behavior. They argued in favor of holistic, distributed representation of learned step co-occurrence associations. Two experiments found that people can adapt routine procedural behavior to changing circumstances quite readily and that other factors besides statistical co-occurrence can have influence on action selection. A CSM-inspired ACT-R model of the two experiments is the first to postdict differential error rates across multiple between-subjects conditions and trial types. Results from the behavioral and modeling studies favor a CSM-like theory of human routine procedural memory that uses discrete, hierarchically-organized goal and action representations that are adaptable to new but similar procedures.
A Usability and Real World Perspective on Accessible Voting
(2012) Piner, Gillian E.; Byrne, Michael D.
The HAVA (Help America Vote Act) mandated that all polling places provide privacy and independence to voters. DREs (Direct-Recording Electronic voting systems) have been assumed to be the solution to providing accessible voting, but there is reason to believe extant systems do not adequately serve this goal (Runyan, 2007). Study 1, a mock election, is a first step in addressing the lack of existing data on the usability of accessible voting methods. In comparison with sighted users, blind users took five times longer to vote. Both populations showed similar error rates and types, and reported similarly high satisfaction with the usability of paper ballots. Study 2, a survey, provides the opinions and recommendations of 202 legally blind voters. Data-based recommendations for auditory modes of voting systems include adjustable speed and volume, using male text-to-speech synthesized voices, and allowing for flexible navigation. This research provides a comparison point and guidelines for future studies of accessibility solutions.
An Empirical Analysis of Internet Use on Smartphones: Characterizing Visit Patterns and User Differences
(2012-09-05) Tossell, Chad; Kortum, Philip; Byrne, Michael D.; Lane, David M.; Zhong, Lin
The original vision of ubiquitous computing was for computers to assist humans by providing subtle and fitting technologies in every environment. The iPhone and similar smartphones have provided continuous access to the internet to this end. In the current thesis, my goal was to characterize how the internet is used on smartphones to better understand what users do with technology away from the desktop. Naturalistic and longitudinal data were collected from iPhone users in the wild and analyzed to develop this understanding. Since there are two general ways to access the internet on smartphones—via native applications and a web browser—I describe usage patterns through each along with the influence of experience, the nature of the task and physical locations where smartphones were used on these patterns. The results reveal differences between technologies (the PC and the smartphone), platforms (native applications and the mobile browser), and users in how the internet was accessed. Findings indicate that longitudinal use of web browsers decreased sharply with time in favor of native application use, web page revisitation through browsers occurred very infrequently (approximately 25% of URLs are revisited by each user), bookmarks were used sparingly to access web content, physical location visitation followed patterns similar to virtual visitation on the internet, and Zipf distributions characterize mobile internet use. The web browser was not as central to smartphone use compared to the PC, but afforded certain types of activities such as searching and ad hoc browsing. In addition, users systematically differed from each other in how they accessed the internet suggesting different ways to support a wider spectrum of smartphone users.
Analysis of human movement for a complex dynamic task: What predicts success?
(2013-09-16) Purkayastha, Sagar; O'Malley, Marcia K.; Byrne, Michael D.; Dick, Andrew J.
This thesis identiﬁes and analyzes successful movement strategies for the completion of a complex dynamic task. In the past it has been shown that movement strategies correlate well to performance for simple tasks. Therefore, in this thesis I was motivated to ﬁnd out if motion based metrics correlated well to performance for more complicated motor tasks. First, the Nintendo Wiimote was veriﬁed as a suitable gaming interface enabling gross human motion capture through experimental comparisons with other gaming interfaces and precision sensors. Then, a complex motor task was rendered in an open-source gaming environment. This environment enabled the design of a rhythmic task that could be controlled with the Wiimote while data were simultaneously recorded for later analysis. For the task, success and failure could be explained by high correlation between two motion based performance metrics, mean absolute jerk (MAJ) and average frequency (AVF) per trial. A logistic regression analysis revealed that each subject had a range of MAJ and AVF values for being successful, outside of which they were unsuccessful. Therefore, this thesis identiﬁes motion based performance metrics for a novel motor control task that is signiﬁcantly diﬃcult to master and the techniques used to identify successful movement strategies can be used for predicting success for other such complex dynamic tasks.
Assessing the Usability of the Straight-Party Voting Ballot Option for Paper, Punch Card, and Electronic Voting Systems
(2011) Campbell, Bryan; Byrne, Michael D.
The straight-party voting ballot option (SPVBO) is a voting provision available to a sizable minority of United States voters-approximately 71 million voters across 16 U.S. states. In recent years, researchers have begun to doubt the efficacy of the SPVBO while current research on the usability of the SPVBO is largely anecdotal with little empirical support. From a usability perspective, the SPVBO should be a means of increasing both voting efficiency and voting effectiveness via a reduction in the overall number of task elements require to complete a ballot. An empirical mock election research experiment was conducted to test the usability of the SPVBO using realistic voting equipment and procedures. Results from this experiment suggest that using the SPVBO may have little impact on voting system efficiency or satisfaction and that, in certain circumstances, using the SPVBO may have profound negative effects on voting error rates.
Attention capture by visual onsets and the mediating power of attentional set
(2004) Fick, Chris S.; Byrne, Michael D.
This study examined how attentional set mitigates attention capture by onsets occurring between known spatial locations. In Experiment 1 response times increased with the number of onsets that occurred. In Experiment 2 and 3 color was used instead of onset as the task relevant feature. Data collected at the keystroke-level showed delayed response times for keystrokes in only certain positions following an onset. Typing patterns were also found to affect the costs generated by the onsets, implying that task strategies mediated when onsets captured attention. Experiment 4 manipulated the cue types in a 2 phase spatial cuing task. Cues of the same type in both phases yielded faster responses, even though the blocked nature of the trials alerted participants to the upcoming cue type in each phase. This suggests that participants were unable to rapidly shift attentional set.
Changing the interface with minimal disruption: The roles of layout and labels
(2006) Chung, Phillip H.; Byrne, Michael D.
This dissertation reports findings from two laboratory experiments and a field study demonstrating significant reliance by users on interface layout information in interactive tasks. In Experiment l, a paradigm was introduced where either the layout of the interface was changed or labels were removed, after participants completed a minimum of eleven trials of a routine computer-based task. Since layout change had a more detrimental effect on performance, in Experiment 2, two methods expected to mediate that effect were explored: the addition of color and a layout based on a simple preexisting rule of top-to-bottom control order. Only the latter was effective, showing that introducing an interface layout that leverages preexisting knowledge can actually improve task performance. In the field study, a methodology was developed to put these findings to the test at a local family medicine clinic using an electronic medical records system. By studying nurses' use of an existing data entry form, a new form was designed to more closely follow their workflow. Similar to the top-to-bottom control order manipulation in Experiment 2, the new form layout seemed to produce better performance and was liked better by the nurses. Thus, in contrast to the vast body of literature in the field that has emphasized the importance of label information (e.g., Polson & Lewis, 1990) and goal structure (e.g., John & Kieras, 1996) in computer-based tasks, these findings reveal that users quickly learn to rely on layout information.
CHILVote: The design and assessment of an accessible audio voting system
(2013-09-16) Piner, Gillian E.; Byrne, Michael D.; Kortum, Philip; Lane, David M.; Wallach, Dan S.
The Help America Vote Act, passed into law in 2002, mandated that all polling places provide privacy and independence to all voters. Given this, many jurisdictions have been forced into making a choice between providing traditional voting methods (such as paper ballots) and offering newer electronic voting systems. Electronic voting machines have been seen as the solution to many usability and accessibility problems, but very little literature exists to indicate whether this is the case among speciﬁc populations such as disabled, elderly, and non-English speaking voters. An audio accessible voting interface for visually disabled voters (CHILVote) was designed using speciﬁcations from both the Voluntary Voting System Guidelines and a largescale survey of blind individuals conducted by Piner and Byrne [in proceedings of The Human Factors and Ergonomics Society 55th Annual Meeting, pp. 1686-1690 (2011)]. CHILVote’s interface utilizes the given design guidelines and includes use of a male text-to-speech voice, a ﬂexible navigation structure, adjustable speed and volume, and an optional review section. Relatively low error rates (M=1.7%) and high SUS scores (M=89.5) among blind subjects are consistent with previous ﬁndings. Error rates and satisfaction are not signiﬁcantly different than those of sighted voters using both paper and DRE, and blind voters using a non-electronic interface. CHILVote signiﬁcantly reduced the time it takes for blind subjects to vote, from 25.2 minutes (VotePAD) to 17.1 minutes (CHILVote). This is an improvement, but still over 2.5 times slower than sighted subjects voting on an identical ballot. The integration of accessibility into mainstream technology often has beneﬁts beyond allowing more of the population access to a system. This research provides a comparison point and guidelines for future studies of accessibility solutions.
Computational modeling of icon search
(2002) Fleetwood, Michael D.; Byrne, Michael D.
As the use of graphical user interfaces expands into new areas, icons are becoming an increasingly important aspect of GUIs. Oddly, little research has been done into the costs and benefits associated with using icons. A set experiments was conducted in which various attributes of icons were examined, including simple icon borders, icon "quality" and set size (number of "distractor" icons). An eye tracking study of the task was also conducted to examine the icon search strategies of computer users. Based on the results of the studies, two models were then constructed in ACT-R/PM to carry out the same task as in the experiments. The final iteration of the models was predictive of human performance in icon search tasks. Insights into icon design and computational modeling of icon search are discussed.
Computational Modeling Reveals How Navigation Strategy and Ballot Layout Lead to Voter Error
(2020-09-16) Wang, Xianni; Byrne, Michael D.
Bad ballot design has affected the outcome of multiple elections in the United States. In order to build an automated tool for evaluation of ballots for potential usability problems, a range of voting behaviors on different ballot layouts have to be understood and modeled. The current studies are focussed on full-face paper ballots. Study 1 is an eye-tracking study. The ways that voters seek information on a full-face paper ballot was examined and the insights from the analysis results were integrated into Study 2. Study 2 is a cognitive modeling study. A family of 160 voting strategies were modeled using ACT-R to investigate how errors arise from the interaction of strategy and ballot design. The model was then validated by testing on a well-known bad ballot: the ballot from Kewaunee County, Wisconsin 2002. The Wisconsin error was reproduced successfully.
Effects of Multiple Races and Header Highlighting on Undervotes in the 2006 Sarasota General Election: A Usability Study and Cognitive Modeling Assessment
(2011) Greene, Kristen K.; Byrne, Michael D.
Large-scale voting usability problems have changed the outcomes of several recent elections. The 2006 election in Sarasota County, Florida was one such incident, where the number of votes lost was nearly 50 times greater than the margin of victory for the US Representative race. Multiple hypotheses were proposed to explain this incident, with prevailing theories focused on malicious software, touchscreen miscalibration or poor ballot design, Study I aimed to empirically determine whether Sarasota voters unintentionally skipped the critical US Representative race due to poor ballot design. The Sarasota ballot was replicated initially, then header highlighting and number of races presented on the first screen were manipulated. While the presentation of multiple races had a significant effect on undervotes in the US Representative race, header highlighting did not. Nearly 20% of all voters (27 of 137) skipped the race their first time on that screen, an even greater undervote rate than that originally seen in Sarasota. In conjunction with other research, Study I results strongly suggests that the 2006 Sarasota election was almost certainly a human factors problem. A cognitive model of human voters was developed based on Study I data. Model predictions were then compared with behavioral data from Study 2, in which participants voted on a replica of the Charlotte County, Florida 2006 ballot.
Expert Surgeons Can Smoothly Control Robotic Tools With a Discrete Control Interface
(IEEE, 2019) O'Malley, Marcia K.; Byrne, Michael D.; Estrada, Sean; Duran, Cassidy; Schulz, Daryl; Bismuth, Jean
Objective assessment of surgical skill is gaining traction in a number of specialty fields. In robot-assisted surgery in particular, the availability of data from the operating console and patient-side robot offers the potential to derive objective metrics of performance based on tool movement kinematics. While these techniques are becoming established in the laparoscopic domain, current assessment techniques for robotic endovascular surgery are based primarily on observation, checklists, and grading scales. This work presents an objective and quantitative means of measuring technical competence based on analysis of the kinematics of endovascular tool tip motions controlled with a robotic interface. We designed an experiment that recorded catheter tip movement from 21 subjects performing fundamental endovascular robotic navigation tasks on a physical model. Motion-based measures of smoothness (spectral arc length and number of submovements) were computed and tested for correlation with subjective scores from a global rating scale assessment tool that has been validated for use when performing manual catheterization. Results show that the smoothness metrics that produced significant correlations with the global rating scale for manual catheterization show similar correlations for robotic catheterization. This finding is notable, since with the robotic interface, tool tip motion is commanded discretely via a control button interface, while in manual procedures the tools are controlled through continuous movements of the surgeon's hands. Logistic regression analysis using a single motion metric was capable of classifying subjects by expertise with better than 90% accuracy. These objective and quantitative metrics that capture movement quality could be incorporated into future training protocols to provide detailed feedback on trainee performance.
Flying under the radar: Studying inattentional blindness in a dynamic task
(2007) Fick, Chris S.; Byrne, Michael D.
These three experiments examined noticing rates of an unexpected object (UO) that appeared during a dynamic aircraft threat evaluation task that required participants to shift their visual attention between multiple task-relevant locations. Experiment 1 manipulated the location at which the UO appeared; no effects on noticing rates were found. However, eye-tracking data revealed trends for UOs to be noticed more when participants were looking at locations closer to where the UO appeared, or when they were making more eye-movements while the UO was present. Eye-tracking data also showed a strong link between making an eye movement to the UO and noticing it. Experiment 2 manipulated the color, direction and speed of the UO to make it more or less similar to task-relevant objects. Also, to-be-ignored (TBI) aircraft were either present or absent for each participant. An interaction between the color of the UO and the presence of TBI aircraft was found with noticing rates being greater for uniquely-colored UO's only when no TBI aircraft were present. No overall effect of UO and target aircraft similarity was found. Experiment 3 manipulated the visual complexity and cognitive difficulty of the task. Noticing rates were higher only in the visually-simple, cognitively-easy, task pairing. These findings reveal the importance of participants' task strategies, attentional set and the interaction with task complexity unexplored by current theories of visual attention and prior findings from research on inattentional blindness. Also discussed are the implications for designers of human-machine systems.
From Error to Error: Why Voters Could not Cast a Ballot and Verify Their Vote With Helios, Prêt à Voter, and Scantegrity II
(USENIX, 2015) Acemyan, Claudia Z.; Kortum, Philip; Byrne, Michael D.; Wallach, Dan S.
The aim of this paper is to identify user errors, and the related potential design deficiencies, that contributed to participants failing to vote cast and vote verify across three end-to-end voting systems: Helios, Prêt à Voter, and Scantegrity II. To understand why voters could not cast a vote 42% of the time and verify that their ballots were cast and counted with the tested e2e systems 53% of the time, we reviewed data collected during a system usability study. An analysis of the findings revealed subjects were most often not able to vote with Helios because they did not log in after encrypting their ballot but before casting it. For both Prêt à Voter and Scantegrity II, failing to vote was most frequently attributed to not scanning the completed ballot. Across all three systems, the most common reason participants did not verify their vote was due to not casting a ballot in the first place. While there were numerous usability failures identified in the study, these errors can likely be designed out of the systems. This formative information can be used to avoid making the same types of mistakes in the next generation of voting systems—ultimately resulting in more usable e2e methods.
How To Build an Undervoting Machine: Lessons from an Alternative Ballot Design
(USENIX, 2013-08) Greene, Kristen K.; Byrne, Michael D.; Goggin, Stephen N.
Despite the importance of usability in ensuring election integrity, it remains an under-studied aspect of voting systems. Voting computers (a.k.a. DREs) offer the opportunity to present ballots to voters in novel ways, yet this space has not been systematically explored. We constructed a DRE that, unlike most commercial DREs, does not require voters to view every race, but instead starts at the “review screen” and lets voters directly navigate to races. This was compared with a more traditional, sequentially-navigated, DRE. The direct access navigation model had two effects, both of which were quite large. First, voters made omission (undervote) errors markedly more often. Second, voters who were free to choose who to vote for chose to vote in substantially fewer races. We also examined the relationship between the true error rate—which is not observable in real elections—and the residual vote rate, a measure of effectiveness commonly used for real elections. Replicating the findings of [Campbell and Byrne 2009a], the mean residual vote rate was close to the mean true error rate, but the correlation between these measures was low, suggesting a loose coupling between these two measures.
Modeling Curved Movement
(2013-09-16) Gallagher, Melissa; Byrne, Michael D.; Kortum, Philip; Pomerantz, James R.
This work aims to further the understanding of the trajectory and velocity profile of curved motion. Two competing theories, the two-thirds power law and the minimum jerk velocity profile, were tested. A set of two experiments was run that had the subjects generate curved motion. The first experiment had subjects move along a bounded oval and the second experiment had subjects move is a less constrained manner inducing a curved path. The study shows evidence for the expected effects of distance travel and allowable room for error. The evidence for the two movement profiles explaining the data is minimal.
Quantitative Movement Analysis in Endovascular Surgical Tasks for Objective Determination of Skill
(2014-04-28) Estrada, Sean J; O'Malley, Marcia K.; Meade, Andrew J., Jr.; Byrne, Michael D.
Endovascular surgeons use catheters placed under the skin to access vascular structures, via minimally invasive techniques, in order to treat disease. Endovascular surgery is one of the most rapidly expanding specialties, and the spectrum of cases, from basic to complex, demands a wide range of skills from operators. A key surgical competency requirement is to optimally visualize and utilize pre-shaped catheters and direct vessel interactions, yet current performance assessment techniques are limited to grading scales based solely on subjective ratings. Since most endovascular procedures involve performing fine motor control tasks that require complex, dexterous movements, this thesis explores the potential for a standardized, objective, and quantitative means of measuring technical competence based on analysis of the kinematics of endovascular tool tip motions. To accomplish this goal, an experiment was designed that involved recording the catheter tip movement from twenty-one subjects performing four fundamental endovascular tasks in each of three sessions. Participants performed both manual and robotic methods of catheterization in an inanimate model and performed manual catheterization in a simulation environment with a virtual representation of the same model. Electromagnetic sensors were used to capture catheter tip movement when performing tasks on the physical model, while image processing techniques were used to track catheter tip movements from the fluoroscopic images when performing tasks on the simulator. Several motion-based performance measures that have been shown to reliably assess skill in other domains were computed and tested for correlation with subjective data that were simultaneously obtained from the global rating scale assessment tool. The selected set of motion-based metrics captured both the kinematics of tool tip motion (path length, tip accelerations) and the quality of movement (smoothness). The metrics that captured movement quality produced reliable correlations with the observation-based assessment metrics. Further, these metrics were able to differentiate skill among participants. These objective and quantitative metrics that capture movement quality could be incorporated into future training protocols to provide detailed feedback on trainee performance.
Refining theoretical models of visual sampling in supervisory control tasks: Examining the influence of alarm frequency, effort, value, and salience
(2005) Fleetwood, Michael D.; Byrne, Michael D.
This work is concerned with examining in a formal quantitative manner what human observers look at and what the objects of their gaze tell them. Three models designed to describe and predict the allocation of human attention in supervisory control tasks were investigated. A series of three experiments examined the relative influence of five factors on the sampling patterns of participants: the information generation rate of the information signal (bandwidth), the frequency of significant, i.e., task relevant, events on an information source (alarm frequency), the payoff matrix associated with missing or detecting critical events (value), the visual salience of the events, and the cost of making an observation. The paradigm employed is similar to that developed by Senders and colleagues (1964), in which observers were asked to monitor an array of four simulated ammeters and to press a button whenever the pointer of any ammeter entered an "alarm zone." Aspects of three mathematical models, Senders's constrained random sampler, Wickens and colleagues SEEV model, and Pirolli's and Card's Information Foraging Theory Model, were combined to form seven different models predicting performance in the task. The sampling patterns predicted by each model were compared against the eye movement data of participants. Results of the three experiments indicate that participants' sampling patterns were sensitive to the experimental manipulations. Comparisons of the model predicted patterns of attention allocation to those in the participant data indicated that different models described different participants. Participants who performed poorly at the task were best described by models incorporating bandwidth. Participants who performed well at the task were best described by models incorporating alarm frequency, and those who performed best at the task were not well-described by any of the models. Overall the models based on Information Foraging Theory were the most robust in predicting the attention allocation patterns of participants. Implications of each of the experimental manipulations and of the fit of the models to the participant data are discussed.

Browsing by Author "Byrne, Michael D."

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