Category Archives: Division 21

Blogging APA Division 21: You’re Looking Harmless Today

I‘m on a plane writing this post and I look harmless, or at least not threatening.

According to work presented by Poornima Madhavan from Old Dominion University, being a female in the screening line means I am less likely to be hassled by a false alarm of a screener seeing a threat in my bag.*

In work done with her graduate student Jeremy Brown, Dr. Madhavan found that participants in their studies consistently reported more false alarms (detecting a threat that was not there) when the passenger was male. Both genders showed this bias.

Because this bias affects a perceptual task (detecting a knife in a baggage x-ray) it is called a “Social Cognitive Bias.”

This project is a wonderful example of an applied experiment that gives us information on the effects social and cultural structures can have on cognitive ability.

Photo credit Wayan Vota under a Creative Commons license.

*No matter what gender you are, carrying climbing gear guarantees a search!

Blogging APA Division 21: Maximizing Stimulus-Response Compatibility

Kim-Phuong L. Vu was this year’s winner of the Earl A. Allusi Award for early career achievement. Her presentation covered maximizing stimulus-response compatibility to optimize human performance.

Vu reported on her studies of people’s performance under different levels of stimulus-response compatibility. For example, high stimulus response compatibility occurs when a blinking button needs to be pressed. The blinking is the stimulus and the button press is the response. They become less compatible as the signal for pressing the button moves further from the button itself. In the worst case, a well learned response is reversed – imagine if moving your computer mouse to the right moved the cursor left. This would be terribly incompatible, but would be even worse if you were already well experienced with the mouse moving in a compatible manner.

Vu gave some great examples of how stimulus response compatibility is much more than common sense. In coal mining, the controls for a mine transport operate in one direction (a compatible one) going in to the mine and reverse when leaving. When controlling military drones visually (UAVs) or any remote controlled object, the input controls must be reversed when the machine is flying toward the controller. In my mouse example, it is not common sense for a mouse to work as it does — there is no universal compatibility that moving a mouse forward should move it upwards on the screen. Indeed, many flight input devices work in the opposite way, so that a forward movement makes the plane descend. This compatibility was learned, but nonetheless is disrupted when changed.

Dr. Vu is currently an Associate Professor at California State University, Long Beach, and working on incorporating stimulus-response compatibilities in 3-dimensional interfaces.

Congratulations to Dr. Vu on her award!

For some fun reading by Kim-Phuong Vu and Robert Proctor, see their review chapter on the state of our art:

Proctor, R. W., & Vu, K.-P. L. (2010). Cumulative knowledge and progress in human factors. Annual Review of Psychology (vol. 61). Palo Alto, CA: Annual Reviews.

Blogging APA Division 21

I‘m just returning from APA 2010, where the Division of Applied Experimental & Engineering Psychology presented a number of cutting-edge human factors projects. I’m writing individual posts on many of these, so stay tuned!

Here is a teaser:

  • “How important is your HF work to the human race?”
  • “Get ready for the pat-down, males!”
  • “Too much help is a dangerous thing.”
  • “Our lack of compatibility makes me slow.”
  • “Why are you so stressed out? This is fun!”