Effects of socio-emotional stressors on ventilation rate and subjective workload during simulated CPR by lay rescuers

Several studies have documented the occurrence of high ventilation rates during cardiopulmonary resuscitation, but to date, there have been no scientific investigation of the causes of hyperventilation. The objective of the current study was to test the effects of socio-emotional stressors on lay rescuers' ventilation rate in a simulated resuscitation setting using a manikin model. A within-subjects experiment with randomized order of conditions tested lay rescuers' ventilation rate on an intubated manikin during exposure to socio-emotional stressors and during a control condition where no external stressors were present. Ventilation rates and subjective workload were significantly higher during exposure to socio-emotional stressors than during the control condition. All but one of the nine participants ventilated at a higher ventilation rate in the experimental condition. All nine participants rated the subjective workload to be higher during exposure to socio-emotional stressors. Hence, exposure to socio-emotional stressors is associated with increased ventilation rates performed by lay rescuers during simulated cardiac arrest using a manikin model. These findings might have implications for the understanding of the type of situations which hyperventilation may occur. Awareness of these situations may have implications for training of lay rescues.     

Training Novice Users in Developing Strategies for Responding to Errors When Browsing the Web

Novice users frequently make errors when learning a new computer task and spend a large portion of their time trying to recover from errors. Three methods for helping novice users respond to errors have been presented in the literature: error management training, exploratory training, and conceptual models. In error management training, errors are presented as opportunities for learning, and users are instructed in strategies for coping with errors. In exploration, users are given an overview of their environment and are taught how to navigate through their task environment. Conceptual models are graphical or mathematical representations of a system that correspond closely to the real-world system. This experiment tested the effectiveness of these different approaches on training novice users to use the Internet. In this experiment, users received 3 hr of training on the World Wide Web and then were asked to perform a set of information retrieval tasks. Performance was measured in two ways: task performance and performance time. Participants who received exploratory training had significantly higher task performance. Participants who received exploration and conceptual models, both individually and together, were able to complete the tasks in less time. Error management had no significant effect on the performance of participants. In the task application of Web browsing, exploration seems to be the most appropriate training method for novice users.     

Special Issue in Honor of Ben Shneiderman's 60th Birthday: Reflections on Human-Computer Interaction

Abstract

Unlike most Web portals in the world, Chinese Web portals are characterized by a huge amount of information, excessive visual stimuli, and very long Web pages. The objective of this study is to investigate the effect of such rich Web portal designs and floating animations on visual search, emphasizing a comparison between Chinese users and German users. Two experiments were conducted to test 2 proposed hypotheses. Experiment 1 studied the effect of Web portal design (rich and simple) on visual search performance (performance time, errors, and satisfaction) with both Chinese and German participants. Experiment 2 studied the effects of static animations (leaderboards, couplets, and large squares) and floating animations (moving down, moving up/down, and random movement) on visual search performance on Web portals. The dependent variables were the performance time, error, satisfaction, and animation recognition. The results indicated that participants using simple Web portals searched faster, made fewer errors, and were more satisfied than participants using rich Web portals. No significant differences were found between the performance time of Chinese participants and German participants. However, satisfaction of Chinese participants was found to be less influenced by the differences between simple and rich Web portal designs, compared with German participants. No significant differences were found in performance time and animation recognition between static animations and floating animations, which indicated that users are able to detect the pattern of animation movements and were able to avoid floating animations as well as static animations. People searching pages with randomly floating animations were found to use significantly more time compared with those searching pages with no animations. Furthermore, users' satisfaction for pages with randomly floating animations, moving down animations, and moving up/down animations was significantly lower than for pages with no animations. Implications for designers and for future research are discussed.     

A Comparative Study of Two Wayfinding Aids With Simulated Driving Tasks—GPS and a Dual-Scale Exploration Aid

Global Positioning System (GPS) is currently the most often used wayfinding aid for driving. Yet GPS is originally designed to provide a driving guide rather than to help users gain spatial knowledge. Accordingly, GPS might be less usable in situations where spatial knowledge is required. This study experimentally compared two wayfinding aids using simulated driving tasks in a virtual environment: a simulated GPS and a dual-scale exploration aid (DSEA). The DSEA, which provides two levels of details—both detailed and contextual information—was proposed to support participants in finding and selecting routes by themselves. The results show that although DSEA was less helpful in leading participants to their destination and corresponded to more turning errors in simulated driving, it was more useful for the corresponding participants to establish spatial awareness and a cognitive map. The influence of participants' spatial ability test score on wayfinding performance was measured and discussed. The proposed DSEA design and experimental results show some indications for designing new wayfinding aids aimed at reducing wayfinding errors and constructing cognitive maps while still providing easy navigation.     

TeamSpirit: Design, implementation, and evaluation of a Web-based group decision support system

Distributed teams can carry out critical tasks with appropriate decision support technologies. The architecture and detailed design of a Web-based GDSS, called TeamSpirit, are discussed to address the challenges of building a Web-based GDSS. A series of empirical studies are reported to assess the effectiveness of TeamSpirit in supporting distributed group problem solving when in-person facilitation is not possible. Results indicate that giving creative problem solving training to TeamSpirit participants had positive impacts on team performance. Users who received brief TeamSpirit training were able to design and facilitate virtual meetings by themselves and achieved better team performance than control groups.     

Too good to be bad: Favorable product expectations boost subjective usability ratings

In an experiment conducted to study the effects of product expectations on subjective usability ratings, participants (N = 36) read a positive or a negative product review for a novel mobile device before a usability test, while the control group read nothing. In the test, half of the users performed easy tasks, and the other half hard ones, with the device. A standard usability test procedure was utilized in which objective task performance measurements as well as subjective post-task and post-experiment usability questionnaires were deployed. The study revealed a surprisingly strong effect of positive expectations on subjective post-experiment ratings: the participants who had read the positive review gave the device significantly better post-experiment ratings than did the negative-prime and no-prime groups. This boosting effect of the positive prime held even in the hard task condition where the users failed in most of the tasks. This finding highlights the importance of understanding: (1) what kinds of product expectations participants bring with them to the test, (2) how well these expectations represent those of the intended user population, and (3) how the test situation itself influences and may bias these expectations.     

Automatic usability and stress analysis in mobile biometrics

This article focuses on the usability evaluation of biometric recognition systems in mobile devices. In particular, a behavioural modality has been used: the dynamic handwritten signature. Testing usability in behavioural modalities involves a big challenge due to the number of degrees of freedom that users have in interacting with sensors, as well as the variety of capture devices to be used. In this context we propose a usability evaluation that allows users to interact freely with the system while minimizing errors at the same time. The participants signed in a smartphone with a stylus through the different phases in the use of a biometric system: training, enrolment and verification. In addition, a profound study on the automation of the evaluation processes has been done, so as to reduce the resources employed. The influence of the users' stress has also been studied, to obtain conclusions on its impact on both the usability systems in scenarios where the user may suffer a certain level of stress, such as in courts, banks or even shopping. In brief, the results shown in this paper prove not only that a dynamic handwritten signature is a trustable solution for a large number of applications in the real world, but also that the evaluation of the usability of biometric systems can be carried out at lower costs and shorter duration.     

“I agree to the terms and conditions”: (How) do users read privacy policies online? An eye-tracking experiment

Privacy policies are widely used by online service providers to regulate the use of personal data they collect, but users often skip on reading them and are unaware of the way information about them is being treated, and how they can control the ways in which that information is collected, stored or shared. Eye tracking methodology was used to test if a default presentation of a policy encourages reading it, and how the document is being read by users. Results show that when a privacy policy is presented by default, participants tend to read it quite carefully, while when given the option to sign their agreement without reading the policy, most participants skip the policy altogether. Surprisingly, participants who actively choose to read the policy spend significantly less time and effort on reading it than participants in the default condition. Finally, default policy presentation was significantly related to understanding user rights and restrictions on the use of personal data.     

A multi-level approach of evaluating crew resource management training: a laboratory-based study examining communication skills as a function of team congruence

The article proposes a multi-level approach for evaluating communication skills training (CST) as an important element of crew resource management (CRM) training. Within this methodological framework, the present work examined the effectiveness of CST in matching or mismatching team compositions with regard to hierarchical status and competence. There is little experimental research that evaluated the effectiveness of CRM training at multiple levels (i.e. reaction, learning, behaviour) and in teams composed of members of different status and competence. An experiment with a two (CST: with vs. without) by two (competence/hierarchical status: congruent vs. incongruent) design was carried out. A total of 64 participants were trained for 2.5 h on a simulated process control environment, with the experimental group being given 45 min of training on receptiveness and influencing skills. Prior to the 1-h experimental session, participants were assigned to two-person teams. The results showed overall support for the use of such a multi-level approach of training evaluation. Stronger positive effects of CST were found for subjective measures than for objective performance measures. STATEMENT OF RELEVANCE: This work provides some guidance for the use of a multi-level evaluation of CRM training. It also emphasises the need to collect objective performance data for training evaluation in addition to subjective measures with a view to gain a more accurate picture of the benefits of such training approaches.     

Automation usage decisions: controlling intent and appraisal errors in a target detection task

BACKGROUND: It was proposed that misuse and disuse often occur because operators (a) cannot determine if automation or a nonautomated alternative maximizes the likelihood of task success (appraisal errors) or (b) know the utilities of the options but disregard this information when deciding to use automation (intent errors). OBJECTIVE: This investigation assessed the effectiveness of performance feedback, a procedure developed to attenuate appraisal errors, and scenario training, an intervention designed to decrease intent errors. METHODS: Operators given feedback were told how many errors they and an automated device made on a target detection task. Scenario training took operators through the thought processes of optimal decision makers after the utilities of the automated and nonautomated alternatives had been determined. Following 200 training trials, participants chose between relying on their observations or an automated device. RESULTS: There was little misuse, but disuse rates were high (84%) among operators receiving neither feedback nor scenario training. Operators paired with a more accurate machine and given feedback made approximately twice as many errors as the automated device. Nevertheless, intent errors were commonplace; 55% of the operators who received feedback without scenario training did not rely on automation. Feedback effectiveness was enhanced when used in conjunction with scenario training; the disuse rate decreased to 29%. CONCLUSION: A combination of feedback and scenario training was more effective in mitigating disuse than either intervention used in isolation. APPLICATION: An important application of these findings is that operator training programs should incorporate techniques to control intent and appraisal errors.     

A multi-level approach of evaluating crew resource management training: a laboratory-based study examining communication skills as a function of team congruence

The article proposes a multi-level approach for evaluating communication skills training (CST) as an important element of crew resource management (CRM) training. Within this methodological framework, the present work examined the effectiveness of CST in matching or mismatching team compositions with regard to hierarchical status and competence. There is little experimental research that evaluated the effectiveness of CRM training at multiple levels (i.e. reaction, learning, behaviour) and in teams composed of members of different status and competence. An experiment with a two (CST: with vs. without) by two (competence/hierarchical status: congruent vs. incongruent) design was carried out. A total of 64 participants were trained for 2.5 h on a simulated process control environment, with the experimental group being given 45 min of training on receptiveness and influencing skills. Prior to the 1-h experimental session, participants were assigned to two-person teams. The results showed overall support for the use of such a multi-level approach of training evaluation. Stronger positive effects of CST were found for subjective measures than for objective performance measures.

Statement of Relevance: This work provides some guidance for the use of a multi-level evaluation of CRM training. It also emphasises the need to collect objective performance data for training evaluation in addition to subjective measures with a view to gain a more accurate picture of the benefits of such training approaches.     

Increased memory load during task completion when procedures are presented on mobile screens

The primary objective of this research was to compare procedure-based task performance using three common mobile screen sizes: ultra mobile personal computer (7 in./17.8 cm), personal data assistant (3.5 in./8.9 cm), and SmartPhone (2.8 in./7.1 cm). Subjects used these three screen sizes to view and execute a computer maintenance procedure. Results from 65 student participants indicated a significant difference in completion times between the three screen sizes [F(2, 120)=690, p <0.050], but no differences in subjectively assessed cognitive workload, errors or performance time. Competing memory strategies in procedure-based tasks were revealed through the access frequency and amount of time subjects spent reading the procedure before starting the experiment [F(2, 105)=25.17, p <0.001]. When using the 7 in./17.8 cm screen, users read more of the procedure before executing the procedure. In contrast, when using the smaller screen, users sampled the procedure in longer intervals during execution.     

Experience of automation failures in training: effects on trust,automation bias,complacency and performance

This work examined the effects of operators’ exposure to various types of automation failures in training. Forty-five participants were trained for 3.5 h on a simulated process control environment. During training, participants either experienced a fully reliable, automatic fault repair facility (i.e. faults detected and correctly diagnosed), a misdiagnosis-prone one (i.e. faults detected but not correctly diagnosed) or a miss-prone one (i.e. faults not detected). One week after training, participants were tested for 3?h, experiencing two types of automation failures (misdiagnosis, miss). The results showed that automation bias was very high when operators trained on miss-prone automation encountered a failure of the diagnostic system. Operator errors resulting from automation bias were much higher when automation misdiagnosed a fault than when it missed one. Differences in trust levels that were instilled by the different training experiences disappeared during the testing session.

Practitioner Summary: The experience of automation failures during training has some consequences. A greater potential for operator errors may be expected when an automatic system failed to diagnose a fault than when it failed to detect one.     

An empirical investigation of DSS usage and the user's perception of DSS training

Financial analysts, financed managers, and other finance specialists participated in a laboratory study to examine the perceived value of specific DSS training with DSS usage, the decision process, and task structure. Measures included the frequency of DSS features used, the number of syntax errors made, comfort with and the use of a computer terminal to improve decision effectiveness, and the use of a specific DSS to enhance decision making. Forty-nine participants received DSS training, were randomly assigned to a structured or semi-structured task, and conducted analyses. Results showed that DSS users see a strong positive correlation between their training and the use of a DSS to improve decision making. Significant relationships were also noted between perceptions of training and task structure differences.     

Predictive capability of cognitive ability and cognitive style for spaceflight emergency operation performance

This study explores the effects of cognitive ability (information seeking, inference, spatial recognition, attention span, and attention allocation) and cognitive style (active-reflective, sensing-intuitive, visual-verbal, and sequential-global) on task performance of simulated spaceflight emergency operations that require judgment and operation on a Chinese spaceflight instrument board and the possible interaction effect with training experience. The performance criteria included task completion time and number of human errors. It was found that inference ability, spatial recognition ability, and attention span had significant effects on task completion time, while attention allocation ability had significant effect on the number of error. The participants with a sequential cognitive style made significantly fewer errors than those with a global cognitive style. Training experience significantly decreased task completion time. The participants with sequential cognitive style learnt faster than those with global cognitive style in the spaceflight instrument operations. With increasing training experience, the predictive capability of cognitive ability on performance decreased, whereas the predictive capability of the sequential-global cognitive style on performance increased.     

The influence of training on decision times and errors associated with classifying trunk postures using video-based posture assessment methods

The purpose of this study was to examine the influence of training on the decision times and errors associated with video-based trunk posture classifications. Altogether, 30 amateur and 30 knowledge-based participants completed a three-phase study (pre-training, training, post-training) that required them to classify static trunk postures in images on a computer screen into a posture category that represented the angle of the trunk depicted. Trunk postures were presented in both flexion/extension and lateral bend views and at several distances from the boundaries of the posture categories. Both decision time and errors decreased as distance from the boundaries increased. On average, amateur analysts experienced a larger decrease in decision time per posture classification than knowledge-based analysts (amateur: 0.79?s, knowledge-based: 0.60 s; p <0.05) suggesting that training can have beneficial effects on classification performance. The implications are that the analysis time associated with video-based posture assessment methods can be reduced with appropriate training, making this type of approach feasible for larger-scale field studies. Statement of Relevance:Understanding the role that training can play in reducing errors associated with the use of video-based posture assessment methods may result in more efficient use of these tools by ergonomic practitioners. Reducing decision time and misclassification errors will provide a more efficient, accurate and representative assessment of injury risk.     

Does training in the cold improve cold performance?

Despite the well-described physiological response to cold, little is known about how to best train persons to perform motor tasks in cold conditions. It is unclear if principles of training specificity would apply to motor skill training when cold because cold exposure reduces tactile sensitivity and cognitive function, which may reduce rather than enhance training efficacy. The purpose of this study is to determine whether training in the cold facilitates performance in the cold. To do this, we investigated the effect of cold or thermoneutral training on performance of the Grooved Pegboard Task. Twenty persons (11M, 9F, mean age 31.2 ± 5.44 years) visited the lab on two separate days and were randomly assigned to either a cold (5M, 5F) or thermoneutral (6M, 4F) training group. On day one, participants were tested at baseline and then performed 20 repetitions of the task according to their respective group assignment. Prior to each task repetition during training, the cold training group immersed their hand in cold water (2 °C) while the thermoneutral group immersed their hand in thermoneutral water (34 °C). Following training, participants were tested once again (immediate retention test). During testing, participants performed the task twice; once after immersing their hands in cold water and once after immersing their hands in thermoneutral water. On day two, delayed retention tests were performed. Time to completion and number of errors were recorded during testing. There were no differences in time to completion at delayed retention tests between thermoneutral and cold-trained groups (p = 0.434). The incidence of errors was significantly less in the cold-trained group than the thermoneutral training group at delayed retention testing (p = 0.035). The main finding of this study was that dexterity but not speed was improved by cold training. Further research is required but the findings presented here suggest that industries that require motor tasks in the cold could benefit from training employees in cold conditions.     

When simulated environments make the difference: the effectiveness of different types of training of car service procedures

An empirical analysis was performed to compare the effectiveness of different approaches to training a set of procedural skills to a sample of novice trainees. Sixty-five participants were randomly assigned to one of the following three training groups: (1) learning-by-doing in a 3D desktop virtual environment, (2) learning-by-observing a video (show-and-tell) explanation of the procedures, and (3) trial-and-error. In each group, participants were trained on two car service procedures. Participants were recalled to perform a procedure either 2 or 4 weeks after the training. The results showed that: (1) participants trained through the virtual approach of learning-by-doing performed both procedures significantly better (i.e. p < .05 in terms of errors and time) than people of non-virtual groups, (2) the virtual training group, after a period of non-use, were more effective than non-virtual training (i.e. p < .05) in their ability to recover their skills, (3) after a (simulated) long period from the training—i.e. up to 12 weeks—people who experienced 3D environments consistently performed better than people who received other kinds of training. The results also suggested that independently from the training group, trainees’ visuospatial abilities were a predictor of performance, at least for the complex service procedure, adj R ² = .460, and that post-training performances of people trained through virtual learning-by-doing are not affected by learning styles. Finally, a strong relationship (p < .001, R ² = .441) was identified between usability and trust in the use of the virtual training tool—i.e. the more the system was perceived as usable, the more it was perceived as trustable to acquire the competences.     

Infant life jacket donning trials using children and their parents: Comparison to the Canadian standard

IntroductionCanadian drowning rates for children are high and an increased demand for child flotation devices with novel designs is expected. This experiment was conducted to: 1) record the donning performance of life jackets on children/infants using the methods outlined in the Canadian standard; and 2) to compare the donning performance results to the previously reported results using a soft manikin.MethodFour different child life jackets were procured for evaluation. Adults and their children were recruited from the Halifax region to participate.ResultsFifty-five participants completed at least one donning trial with one of the four life jackets. Findings were in general agreement with the previous manikin study. Manikin testing showed consistent results with human testing for life jackets that are both well designed or poorly designed, but were not consistent for “mediocre” life jackets. Each sub-task added 10 s to the donning process. Incorrect donning was yet again caused by clips and ties that were not colour and/or size coded.Conclusions & recommendationsA manikin may be offered as an alternative for a human in the donning tests. For “mediocre” life jackets that fail the manikin test, a human test can always be used to clarify the situation.     

Influences of general computer experience and age on library database search performance

Two experiments examined the effects of general computer experience and age on library system search performance among novice library system users. Twenty younger adults (10 with high and 10 with low computer experience) and 20 older adults (10 with low and 10 with no computer experience) performed 10 search tasks of varying difficulty. Search success, syntax errors, database field specifications, keyword specifications, and use of Boolean operators were examined. Among younger novices, high computer experience was associated with slightly better performance than low computer experience. Among older novices, having some computer experience was associated with much better performance than no computer experience. Older computer users showed lower overall success rates, made more syntax and field specification errors, and demonstrated poorer understanding of Boolean logic and keyword matching algorithms than younger adults with similar computer experience. Implications for interface design and training interventions for novice on-line library system users are discussed.