# QUEST question

**URL:** <https://psychtoolbox.discourse.group/t/quest-question/862>\
**Category:** Uncategorized\
**Created:** [January 8, 2002, 3:38pm UTC](https://psychtoolbox.discourse.group/t/quest-question/862 "2002-01-08T15:38:23Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\
**Post date:** [January 8, 2002, 3:38pm UTC](https://psychtoolbox.discourse.group/t/quest-question/862/1 "2002-01-08T15:38:23Z")

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Hello,  
  
I am using the psychtoolbox to test orientation discrimination in   
noise, and have implemented the QUEST staircase for threshold   
estimation. I would like to set my prior threshold estimate for QUEST   
at the beginning of each run to be a multiple of the predicted   
threshold (e.g. tGuess = 2x predicted threshold). However, this means   
that under conditions where a higher threshold is predicted, the   
staircase doesn't settle onto a value until much later in the run.  
  
Is there a way that I can increase the 'step-size' at the beginning  
of   
each run proportionally?   
  
Thanks in Advance,  
  
Nicole Anderson  
McMaster University