Design, Develop, Create

Wednesday, 7 September 2016

The Avalanche case

Similar case: 6 skiers survive backcountry avalanche near Whistler: Report by CBC (link).

From Bill Buxton's "Sketching User Experiences" (Buxton, 2007).
This case sets up the issues for high-tech design, design that works 'in the wild', that works for real people in real situations and facilitates achieving their human goals.

Bill Buxton sets the scene with the avalanche responder case. It is an incident experienced by his good friend Saul Greenberg, Saul's wife, and three friends when skiing in high mountainous terrain in Canmore and Kananaskis Country, Alberta, Canada.

The group was traversing a valley slope when a lethal avalanche fell across their path. The three skiers in the middle of the group were caught in the slide. The lead (Saul's wife) and the last skier could only watch the disaster unfold as three of the following skiers were engulfed by the avalanche. One was simply knocked down, one was buried up to her shoulders, and the last, Saul, was missing.
Avalanche path and path of ski group collide

What is the normal procedure when traversing avalanche prone terrain? The equipment carried consists of transceivers, probes, and collapsible shovels. But more than just the technology; it also requires knowledge, shared practices, skills, and analysis of a concrete situation (among others).

When skiing in avalanche prone conditions, you work one of a number of simple systems depending on the severity of the risk. The normal procedure when traversing is to spread out and post lookouts at either end, and traverse one-by-one. If an avalanche occurs:

  1. Retain one lookout (you may be hit by another avalanche). 
  2. Triage; rescue the most able first (and they may be able to assist later). 
  3. Go to the approximate location of buried victims, judge if carried onwards, then guide using transceiver. 
  4. Use an avalanche probe to locate the body. 
  5. When the victim is felt you start to dig and dig. 

"Steve, who was higher, checked up on Shane (who was okay), then immediately went to his wife. He freed her arms, and made sure her head was above the snow." 
"Judy went directly to the spot where she had last seen Saul... In order to pinpoint Saul's location, Judy used her avalanche transceiver. ... Using this, she walked a particular pattern on the snow, employing the loudness of a ping (determined by the strength of a signal from Saul's transceiver) to guide her closer and closer to a spot above where he was buried." 
"Judy started digging. Steve arrived and asked if she had verified the spot with her probe, she hadn’t. Judy was confident that she had the right spot, but by this time she had had to dig so deep that her confidence was wavering…"
Saul had tried to ski his way out of it but got caught in the hollow (avalanches can travel at up to 200km/hr whereas 40km/hr is really fast for a skier).
Saul got caught in the trough, a ‘feature trap’, that also meant he was buried deep! But he had cupped his hand over his mouth and nose, preserving a small air space so he could breathe.
He waited, buried under the weight of the snow, and tried to relax. He had to trust in his partners, their training, his and their gear.
None of the participants had ever been in this situation before. Time elapsed from avalanche impact to rescue was about 10 minutes. Under the conditions, after 20 minutes he would have been dead.
(Buxton, 2007) 

Question: After the 'who'; what saved Saul?

Instructional videos by Canadian Forest Rescue SEE SAFETY (

Design related material:
Source: Buxton, B. (2007) Sketching User Experiences: Getting the Design Right and the Right Design, San Francisco, Morgan Kaufmann. (Video examples for the book can be found at the publisher's companion site)
Bill's homepage (