# Interleaved staircase terminates after first trial

**URL:** <https://discourse.psychopy.org/t/interleaved-staircase-terminates-after-first-trial/20325>\
**Category:** Builder\
**Created:** [February 9, 2021, 11:37am UTC](https://discourse.psychopy.org/t/interleaved-staircase-terminates-after-first-trial/20325 "2021-02-09T11:37:57Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Helena\_Blackmore](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/helena_blackmore/32/14050_2.png) [@Helena\_Blackmore](https://discourse.psychopy.org/u/Helena_Blackmore)\
**Post date:** [February 9, 2021, 11:37am UTC](https://discourse.psychopy.org/t/interleaved-staircase-terminates-after-first-trial/20325/1 "2021-02-09T11:37:57Z")

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I am very new to Psychopy ( and extreme beginner in Python). I would appreciate any help. My problem is likely to be very simple, but I can’t figure out what exactly to fix and how.

**OS** (e.g. Win10): Win10  
**PsychoPy version** (e.g. 1.84.x): v2020.2.8  
**Standard Standalone? (y/n)** If not then what?:  
**What are you trying to achieve?:** I need to implement interleaved staircase, similar to delay discountin task. I want to change delays (corresponding to different staircases) and participants choose between two drink options, one of which will have increasing/decreasing monetary incentive associated with it. i.e. " A or B +0.50" → “A or B+1.50” etc.

**What did you try to make it work?:** google, forums, checking code elements

**What specifically went wrong when you tried that?:** The experiment will not continue past the first trial.  
I get the following error:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/9/d/9d27e7894dabeaff1fd65d82cdbd08c700e757a9.png)

I suspect there is a problemwith some of the code elements (screenshot below), maybe specifying the correct response?

This is the excel file:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/c/4/c45d389863ee1d8ba5bf6a6bd691c9da8d225711.png)

code element specifying correct answer and side where options appear :

 ![image](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/2/a/2a942ea474f122bf624ca53426ec0ae0bd469168.png)

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<div class="post-metadata">

**Author:** ![Helena\_Blackmore](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/helena_blackmore/32/14050_2.png) [@Helena\_Blackmore](https://discourse.psychopy.org/u/Helena_Blackmore)\
**Post date:** [February 11, 2021, 1:13pm UTC](https://discourse.psychopy.org/t/interleaved-staircase-terminates-after-first-trial/20325/2 "2021-02-11T13:13:17Z")

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![corrAns](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/c/0/c03ed5545932da4403eaa784ffcd8d536fc089bf.png)

I have now edited the above code element,but still not working:/