To twist or poke? A method for identifying usability issues with the rotary controller and touch screen for control of in-vehicle information systems

Evaluation of the visual-manual resources required to perform calling and navigation tasks in conventional mode with a portable phone and in full- touch mode with an embedded system

This study investigates the differences in a driver's visual-manual behaviour when performing secondary tasks while driving under the full-touch mode (FTM) and the conventional mode (CM). To this end, 30 participants were recruited to perform secondary tasks while driving two vehicles equipped with different HMI system interaction modes. The results show that compared to the CM, in the FTM, fewer visual-manual resources are required to perform the calling task, but for the navigation task, this requirement is higher. Additionally, in both modes, the driver exhibited self-regulation visual-manual behaviour when performing secondary tasks as the driving speed increased. However, the effect of the driving speed on visual-manual behaviour was greater in the FTM than in the CM. The main limitation of this study is that the effect of the difference between the two experimental vehicles on the findings was not considered, however, this does not affect the generalisation of the findings. Practitioner summary: Potential applications of this study include improving drivers' knowledge about the effect of performing secondary tasks in different modes on driving safety, and this study also provides useful insights human-machine co-driving systems to develop user-friendly control strategies and for automotive companies to improve the full-touch interactive mode for automotive companies.

Input modality matters: A comparison of touch, speech, and gesture based in-vehicle interaction

Innovative input devices are being available for in-vehicle information systems (IVISs). While they have the potential to provide enjoyable driving by enabling drivers to perform non-driving related tasks (NDRTs) in more natural ways, the associated distracting effects should be paid with more attention. The purpose of this exploratory study was to compare the effects of three novel input modalities, i.e., touchscreen-based interaction (TBI), speech-based interaction (SBI), and gesture-based interaction (GBI), on driving performance and driver visual behaviors. Moreover, we examined if the influence of different modalities would be moderated by the difficulty level of NDRTs. A total of 36 participants were invited to a simulated driving experiment where they were randomly assigned to one of the four groups (TBI, GBI, SBI or baseline) and completed three driving trials. The results showed that TBI led to the worse driving performance, as indicated by the significantly prolonged reaction time, reduced minimum time-to-collision, and increased variations in both longitudinal and lateral vehicle control. The deteriorated driving performance could be attributed, at least partially, to the intense visual demand induced by looking towards the touchscreen, as indicated by more and longer off-the-road glances. The adverse impacts of GBI were relatively smaller, but it still posed great crash risk by leading to a shorter minimum time-to-collision and less stable vehicle control compared to the baseline. SBI, although not completely equivalent to the baseline group, showed the minimum influence on driving and visual performance. Only very few interaction effects were found, suggesting that the effects of modality were quite robust across different NDRTs. It was concluded that SBI and GBI provided safer alternatives to in-vehicle interaction than TBI.

Fitts' law on the flight deck: evaluating touchscreens for aircraft tasks in actual flight scenarios

This research investigated the effects of an abnormal flight environment using touch-based navigation displays (TNDs). Fitts' law was used to compare the performance of TNDs with control display units (CDUs) and mode control panel (MCPs) under three different flight scenarios (normal, turbulence and startled). A within-subjects design involving 15 male participants was used. Data were collected in respect to accuracy, movement time, subjective feelings, choices and comments. The results showed that under abnormal conditions, TNDs showed worse operation performance and stability than CDUs and MCPs; however, it was easy to learn from TNDs, and they provided a good user experience. Moreover, this research demonstrated the application of Fitts' law to describe pilot behaviours in interactive flight devices, particularly for tasks involving real flight operations. TND designs for aviation could be developed based on these findings to improve flight crew performance when using new technology.Practitioner summary: This research built a Fitts' law model to evaluate the performance of aircraft cockpit touchscreens under normal, turbulence and startled scenarios. We compared the different touchscreens (TNDs) with other traditional interactive devices, such as CDUs and MCPs. The results have implications for the design of aircraft cockpit touchscreens and define the task scenario. Furthermore, the results contribute to the development of scenes utilising Fitts' law.

Exploring the performance of click and slide gestures on large in-vehicle touch screens

Because of the operation distractions created by large in-vehicle touch screens, it is necessary to explore the influence of the locations at which clicking and sliding gestures are performed on driving safety and operation performance. This study conducted two experiments to identify an easy operation area. In experiment 1, the influence of control size and control position on click offsets was discussed. The results showed that click offsets increased with increasing control size. Click offsets were larger at positions blocked by a driver's arm and that were far away from drivers. The click accuracy equation was fitted for different hot zone sizes. Experiment 2 focused on identifying easy sliding ranges. The results revealed sliding areas for 20%, 50%, and 80% of users under different sliding directions and positions. This study identified easy and difficult areas for users to operate large in-vehicle touch screens, providing theoretical guidance for display buttons arrangement.

An Application of Machine Learning for Police Mobile Computer Terminal Usability Evaluation

Police in-vehicle technologies especially mobile computer terminals (MCTs) are the major cause of motor vehicle crashes for law enforcement officers. Previous studies have found several usability issues with the design of MCT interfaces. The objective of this study was to develop an algorithm for classification of MCT interface usability based on a combination of officer performance, visual attention allocation, and subjective measures. It was found that speed deviation, secondary task completion time, off-road fixation frequency and glance duration are informative features that associate with MCT usability. The developed algorithm has the potential to be used in MCT design and development process to ensure efficient interaction in multi-tasking situations of driving and using the MCT.

Future technology on the flight deck: assessing the use of touchscreens in vibration environments

Use of touchscreens in the flight deck has been steadily increasing, however, their usability may be severely impacted when turbulent conditions arise. Most previous research focusses on using touchscreens in static conditions; therefore, this study assessed touchscreen use whilst undergoing turbulent representative motion, generated using a 6-axis motion simulator. Touchscreens were tested in centre, side and overhead positions, to investigate how turbulence affected: (1) error rate, movement times and accuracy, (2) arm fatigue and discomfort. Two touchscreen technologies were compared: a 15" infra-red and a 17.3" projected capacitive touchscreen with force sensing capability. The potential of the force sensing capability to minimise unintentional interactions was also investigated. Twenty-six participants undertook multi-direction tapping (ISO 9241; ISO 2010 ) and gesture tasks, under four vibration conditions (control, light chop, light turbulence and moderate turbulence). Error rate, movement time and workload increased and usability decreased significantly, with screen position and increasing turbulence level. Practitioner Summary: This study evaluated the use of infra-red and projected capacitive touchscreen technologies using multi-directional tapping and gesture tasks, whilst being subjected to different levels of turbulence representative motion. Performance degraded significantly with increasing turbulence level and touchscreen location. This has implications for future flight deck design.

Creating the environment for driver distraction: A thematic framework of sociotechnical factors

As modern society becomes more reliant on technology, its use within the vehicle is becoming a concern for road safety due to both portable and built-in devices offering sources of distraction. While the effects of distracting technologies are well documented, little is known about the causal factors that lead to the drivers' engagement with technological devices. The relevance of the sociotechnical system within which the behaviour occurs requires further research. This paper presents two experiments, the first aims to assess the drivers self-reported decision to engage with technological tasks while driving and their reasoning for doing so with respect to the wider sociotechnical system. This utilised a semi-structured interview method, conducted with 30 drivers to initiate a discussion on their likelihood of engaging with 22 different tasks across 7 different road types. Inductive thematic analysis provided a hierarchical thematic framework that detailed the self-reported causal factors that influence the drivers' use of technology whilst driving. The second experiment assessed the relevance of the hierarchical framework to a model of distraction that was established from within the literature on the drivers use of distracting technologies while driving. The findings provide validation for some relationships studied in the literature, as well as providing insights into relationships that require further study. The role of the sociotechnical system in the engagement of distractions while driving is highlighted, with the causal factors reported by drivers suggesting the importance of considering the wider system within which the behaviour is occurring and how it may be creating the conditions for distraction to occur. This supports previous claims made within the literature based model. Recommendations are proposed that encourage a movement away from individual focused countermeasures towards systemic actors.

What technologies do people engage with while driving and why?

This paper presents the findings of a semi-structured interview study that was conducted to identify drivers' self-reported likelihood of engaging with technologies that are now commonly found in modern automobiles. Previous research has focused on the effect these technological tasks have on driving performance, but there has been less focus on how, why and when drivers choose to engage with them. As distraction remains a significant contributor to road accidents, an understanding of why it occurs will give important insights into how it can be prevented. A semi-structured interview schedule was developed to allow drivers to discuss the factors that influence their decision to engage with a variety of different technologies. The methodology facilitated both quantitative ratings of the drivers' likelihood of engaging in a variety of tasks and qualitative insights into why. Age and gender had some influence on the propensity to engage, in line with other findings in the literature, as did road type and task type. The reasons drivers gave for why they engage with potentially distracting tasks inform recommendations for preventing distraction related accidents from the increasingly prevalent sources of technologies available to drivers.

Touchscreen interfaces in context: A systematic review of research into touchscreens across settings, populations, and implementations

Although many studies have been conducted on the human factors and ergonomics (HFE) of touchscreens, no comprehensive review has summarized the findings of these studies. Based on a schema (three dimensions of understanding critical for successful display selection) presented by Wickens et al. (2004), we identified three dimensions of analysis for touchscreen implementations: touchscreen technology, setting and environment of implementation, and user population. We conducted a systematic review based on the PRISMA protocol (Moher et al., 2009), searching five article databases for relevant quantitative literature on touchscreens. We found that all three dimensions of analysis have a significant effect on the HFE of touchscreens, and that a selection for or against touchscreens must take into consideration the specific context of system interaction in order to maximize safety, performance, and user satisfaction. Our report concludes with a set of specific recommendations for systems designers considering touchscreens as input/output devices, and suggestions for future study into the HFE of touchscreens.

To twist, roll, stroke or poke? A study of input devices for menu navigation in the cockpit

Modern interfaces within the aircraft cockpit integrate many flight management system (FMS) functions into a single system. The success of a user's interaction with an interface depends upon the optimisation between the input device, tasks and environment within which the system is used. In this study, four input devices were evaluated using a range of Human Factors methods, in order to assess aspects of usability including task interaction times, error rates, workload, subjective usability and physical discomfort. The performance of the four input devices was compared using a holistic approach and the findings showed that no single input device produced consistently high performance scores across all of the variables evaluated. The touch screen produced the highest number of 'best' scores; however, discomfort ratings for this device were high, suggesting that it is not an ideal solution as both physical and cognitive aspects of performance must be accounted for in design.

PRACTITIONER SUMMARY

This study evaluated four input devices for control of a screen-based flight management system. A holistic approach was used to evaluate both cognitive and physical performance. Performance varied across the dependent variables and between the devices; however, the touch screen produced the largest number of 'best' scores.

Modelling the hare and the tortoise: predicting the range of in-vehicle task times using critical path analysis

Analytic models can enable predictions about important aspects of the usability of in-vehicle information systems (IVIS) to be made at an early stage of the product development process. Task times provide a quantitative measure of user performance and are therefore important in the evaluation of IVIS usability. In this study, critical path analysis (CPA) was used to model IVIS task times in a stationary vehicle, and the technique was extended to produce predictions for slowperson and fastperson performance, as well as average user (middleperson) performance. The CPA-predicted task times were compared to task times recorded in an empirical simulator study of IVIS interaction, and the predicted times were, on average, within acceptable precision limits. This work forms the foundation for extension of the CPA model to predict IVIS task times in a moving vehicle, to reflect the demands of the dual-task driving scenario.

PRACTITIONER SUMMARY

The CPA method was extended for the prediction of slowperson and fastperson IVIS task times. Comparison of the model predictions with empirical data demonstrated acceptable precision. The CPA model can be used in early IVIS evaluation; however, there is a need to extend it to represent the dual-task driving scenario.