Hi All,

I’m just trying to get to grips with the current (3) version of psychopy and online studies. Can anyone confirm whether staircases (and particularly interleaved staircases) are implemented in the current version?

Currently I’m getting this error upon html compilation: “AttributeError: ‘StairHandler’ object has no attribute ‘writeInitCodeJS’”.

Does this mean that builder wont yet compile staircases to html? If that’s the case am I better delving into psychoJS? I’m trying to stick to builder as much as i can as I intend teaching my undergraduates and some faculty to use psychopy for their online studies. Hence trying to concentrate my efforts on a single (easier) platform.

    • And thanks for all your efforts so far, this is looking great! - -

Best wishes,


Yes, staircases aren’t yet in the PsychoJS library so can’t be used in online studies. This first period of work has been focussed mostly on getting the server working and making it as easy as possible to connect from the app. There will be a new wave of PsychoJS development soon though, where we’ll hopefully be adding

  • movies
  • slider (rating) scales
  • staircases
  • polygon
  • better timing


Hello ,
I’ve noticed that this question is from August 2018. I would like to ask if now it is possible to use the staircase for online experiments? I have tried to use it and the experiment does not run in pavlovia but it runs locally.

I would appreciate any help. Thank you!


Wondering if there is any update, is it possible to use a staircase online?

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I’m also interested in whether staircases will run for online studies :slight_smile:

Sorry, no they haven’t been added yet. The current list of desirables is roughly

  • forms (a la qualtrics)
  • microphone recordings
  • staircases

and I’m not sure the order to prioritise those

I came here to ask the same question about staircases in online. If possible, I’d vote for this to be above the forms and microphone in the priority list. :slight_smile:

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I implemented a staircase class handler that I’m currently using in some psychopy experiments. I’ll put the code here in case is of any help for someone.

It should work both online (with the JS autotranslator) and offline. Only mind that a JS equivalent sum function needs to be added manually. Also, probably test it with your data before using it with real subjects :sweat_smile:


Does anyone know if there is any timeline at all for stair cases to be adapted for online usage?

I made a first experiment using QUEST and due to the current circumstances, I may have to do the replication online.

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For a moment, I thought that quest was now a possibility in online experiments, when I saw Questplus as a new feature. However, it seems that I was wrong.

Does anyone know if there is any timeline at all for stair cases to be adapted for online usage?

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As an update for the curious, QuestPlus is still in development by @richard I believe

In the meantime, @Becca has a live demo of how to get this working using a code component. You could fork that to get started on your own:

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