Archive for category human factors engineering

Child Pedestrian Crossing Study – a few updates

We have just completed this study. Analysis of results and full report are being prepared.

The objective of the research is to lay the foundations for examining whether training child-pedestrians’ HP skills while crossing a road may improve their ability to perceive potentially hazardous situations and to predict hazards prior to their materialization.

  • A first step in developing a training program is to form understanding of child-pedestrians’ traffic behavior patterns. Comparing adults and children provides a depiction of what elements in the traffic environment are crucial for the road-crossing task.
  • In the present study, children and adults participant in a two-phase experiment. They observe typical urban scenarios (see Figure 1) from a pedestrian’s point of view (see Figure 2) and a required to: (1) Press a response button each time they feel it is safe to cross. (2) Describe the features that they perceive as relevant for a safe road-crossing decision, i.e., the conceptual model each group of pedestrians has. Participants’ eye-movements were recorded throughout the experiment utilizing a helmet mounted tracker (Model H6-HS, Eyetrack 6000).
  • To achieve this a three dimensional database of a prototypical Israeli city was built in cooperation with b.design (http://www.b-d.co.il/) , a leading provider of 3-D content. Cars, trees, billboards and various other urban elements were also designed uniquely for this environment. Using the VR-Vantage and VR-Forces different scenarios were developed to examine crossing behavior at various conditions.

 

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Figure 1. The generic city simulated environment presented in the Dome setting (it looks a bit awkward here because its intended to be projected on a dome screen). The Field of View is: (1) Unrestricted (above); (2) Partially obscured by the road’s curvature (middle); (3) Partially obscured by parked vehicles (below).

 

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Figure 2. Simulated environment from a child-pedestrian’s point of view.

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Inexperienced drivers training program – Trailer

Driving is a demanding task combining complex motor and cognitive skills. A typical driving task may include maneuvering among other vehicles, paying attention to various road users (e.g., drivers and pedestrians), and discerning static and dynamic road signs and obstacles). The total amount and rate of information presented to the driver is  more than a human brain can handle at a given time. Thus, the road presents a vast array of accessible information, but drivers notice and attend only to a small fraction of it.

Recent evidence suggests that among all driving skills, only hazard awareness – the ability of drivers to read the road and identify hazardous situations –correlates with traffic crashes (e.g., Horswill and McKenna, 2004). Furthermore, McKenna et al. (2006) have shown that improving hazard awareness skills (via training to identify hazardous situations) resulted in a decrease in risk taking attitudes for novice drivers. These findings and others (e.g., Pradhan et al., 2009; Borowsky et al., 2010; Pollatsek et al., 2006; Deery, 1999) acknowledge that young-novice drivers might be less aware of potential hazards and risks embedded in a situation, and thus are more susceptible to taking risks while driving because of this lack of awareness.

References

Borowsky, A., Shinar, D., & Oron-Gilad, T. (2010). Age and skill differences in driving related hazard perception, Accident Analysis and Prevention, vol. 42, pp. 1240-1249.

Deery, H.A. (1999). Hazard and risk perception among young novice drivers. Journal of Safety Research, 30(4), 225-236.

Horswill, M. S., & McKenna, F. P. (2004). Drivers’ hazard perception ability: Situation awareness on the road. In S. Banbury and S. Tremblay (Eds.), A cognitive approach to situation awareness: Theory and application (pp. 155-175). Aldershot, United Kingdom: Ashgate.

McKenna, F. P., Horswill, M. S., & Alexander, J. L. (2006). Does anticipation training affect drivers’ risk taking? Journal of Experimental Psychology, 12, 1-10.

Pollatsek, A., Narayanaan, V., Pradhan, A., & Fisher, D. L. (2006). Using eye movements to evaluate a PC-based risk awareness and perception training program on a driving simulator. Human Factors, 48, 447–464.

 Pradhan, A. K., Pollatsek, A., Knodler, M., & Fisher, D. L. (2009). Can younger drivers be trained to scan for information that will reduce their risk in roadway traffic scenarios that are hard to identify as hazardous? Ergonomics, 52, 657-673.

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Utilizing Hand Gesture Interaction in Standard PC-based Interfaces

  • This work was conducted by my former graduate student Jenny Grinberg. It focused on how a gesture vocabulary should be applied when gestures are being used in standard window interfaces (Windows, files and folders). We are currently in process of writing up the publication.
  • Interface technologies have only started to adopt hand gestures and most human-computer controls still require physical devices such as keyboard or mouse.
  • To evaluate the influence of keyboard interaction, gestures and combined interaction on user experience an existing hand gesture recognition system (developed by Stern & Efros, 2005) was integrated into a common Windows environment.
  • Two experiments varied in the way the Gesture Vocabulary (GV) was introduced; bulk (Experiment 1) or gradual learning (Experiment 2).
  • Results indicated that all gestures used in the GV were simple and could be executed within a relatively short learning period.
  • Nevertheless, keyboard interaction remained the most efficient, least demanding, and most preferred way.
  • Performance and subjective ratings of gestures and combined interaction were significantly different from those of the keyboard, but not from each other.

Interesting differences among genders emerged:

  • Combined interaction was preferred over gestures-alone among women.
  • With regard to the GV introduction, experiment one revealed that performance time and error rate with gestures were significantly higher for females than for males. However, gradual introduction of gestures (experiment two) improved females’ subjective satisfaction, decreased their performance time, and did not worsen error rate. For males, no such differences were found.
  • Men and women related differently to the gesture displays and women perceived textual labels as more useful.

Here is a screen shot of the application consisting of a standard window which enables to perform the most commonly used commands with folders and files (e.g., open a folder, move the cursor to the right folder, etc.) via hand gestures or via keyboard. To the right is the gesture feedback window (which is part of the gesture recognition system developed by Stern & Efros, 2005).

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  • To the right, the visual display as captured by the gesture recognition camera
  • To the left, the main task window containing files in folders
  • at the bottom of the screen are various parameters regarding the hand’s position and a label with the name of the current command

Gesture Vocabulary (GV) design.

Nine dynamic gestures were defined with one of them as the start/end position. The other eight represented the most commonly used commands in file management navigation processes; right, left, up and down, entering and exiting a folder, and copy/paste commands.

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Here is a video demo of the various gestures used.

Gesture Vocabulary demo

 

Initial findings were reported in Grinberg J. and Oron-Gilad T., Utilizing Hand-Gesture Interaction in Standard PC Based Interfaces, proceeding of the  International Ergonomica Association IEA 2009, Bejing, China.

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