Section 1: Situations of Uncertainty -- Page 13 of 22        Self-Study Guide | OUTLINE | INDEX | Section 1 | Section 2 | Section 3 | Section 4 |Section 5 | REVIEW |

If you took the Uncertainty Prediction Challenge, was it easy to predict when there is a Situation of Uncertainty?
If you say, "No WAY!" then join the club!

And THAT is exactly the point! NO ONE can predict when there is a Situation of Uncertainty.

What I hope you learned from taking the Challenge is that:

THERE ARE NO HARD-AND-FAST RULES FOR FIGURING OUT
WHETHER YOU ARE IN A SITUATION OF UNCERTAINTY!

#1. #2. #3. #4.

For example (photos above are from the Uncertainty Prediction Challenge):


Sharp bend?

• Photo #1 above -- a sharp bend in the road nearby DOES make a Situation of Uncertainty (we can not hear traffic beyond the bend).
• Photo #2 above -- a sharp bend in the road nearby DOES NOT make a Situation of Uncertainty (we can hear traffic from far beyond the bend).
  
  
Speed of traffic?

• Photo #1 above -- the traffic is slow but there IS a Situation of Uncertainty
• Photo #2 above -- the traffic is fast but there IS NOT a Situation of Uncertainty
  
  
Constancy of situation?

• Sometimes conditions can change so that you can hear the vehicles well enough whenever it's quiet at one time, but not at another. For example:
• When the roads are wet, traffic can be heard better than when they are dry.
• Installing a speed hump at the street in photo #4 above made it possible to hear well enough to know it is clear to cross whenever it is quiet (see "Environmental Modifications").
  
• Later in this Section you'll learn that at the crossing where Gordon Parks was killed, there was a Situation of Uncertainty during the day but not in the evening.
• At the street in photo #3 above, parked vehicles created a Situation of Uncertainty because they blocked the sound of traffic. And yet in our research, when we placed a barrier between blind participants and the traffic (see photo), it didn't seem to impair their ability to hear the vehicles much (Wall Emerson & Sauerburger, 2008). So the presence of something that might block the sounds is not a reliable indicator as to whether there is a Situation of Uncertainty either.
  


Long line of sight?

• Photo #2 above -- Can hear the vehicles before they can be seen.
• Photo #4 above -- Can see the vehicles before they can be heard.
• Videos below -- Can see the vehicles long before they can be heard (videos taken by Rikkilyn and Paul Layher).
  
  
  In the Layher's first video below, you can see a car approaching from a quarter mile away on our left, but you cannot hear it until it is only about 5 seconds away (just before the student says "NOW").
  In the second video [right, below] Rikilynn describes the situation and shows the street, which is very straight in both directions with no trees or other obstructions. The cars that we hear are all coming from the left.
  NOTE: The links to the YouTube videos below may not be accessible from restricted sites.
  
  
     

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I hope you understand now that:

the only way to determine if you are in a Situation of Uncertainty is to . . . what?

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