form_text_input/form_multiple_choice: Using space to continue

Comments

• Fab

  September 2021

  Hi @SQuestion,

  I think that because the form_text_input object is designed to accept text, the space bar response is regarded as part of the text inputted by the participant. There may be a way to use code to monitor the content of the text to intercept a space bar response, and to do something similar with the form_multipe_choice object, but I'm not sure how to go about doing that and I suspect it might be tricky and perhaps not worth the trouble.

  However, an alternative would be to display your questions on a sketchpad and use a modified version of the code posted by Sebastiaan here to track the text inputted, display it on the screen, and take the space response as the response that moves to the next object in your experiment. I adapted the code slightly to take the space bar as the response to move on to the next object. You can download below and adapt it to your needs (for example, you might want to implement a check to make sure that the experiment does not move on if the participant didn't type anything, or even to check that it is a numerical value in the case of the age question; you'd have to research Python language a little to work out how to do that):

  Take text input from sketchpad.osexp

  
  

  Of course, a simpler solution would be to just make clear on your screen what participants must press to move on to the next screen. Sure, the coherence across the experiment would not be perfect, but that would spare you some coding.

  As for the sex question, you could simply use a sketchpad + keyboard input object with instruction to press M for male and F for female, rather than using a multiple choice form. Then it would be very simple to take the response, and define the space bar as the key to press to move on. Seems a lot simpler to me.

  Hope this helps,

  Fabrice.

  
• SQuestion

  September 2021

  Hi @Fab,

  
  

  Thanks a lot already! I realised that I can only open .opensesame files but not the .osexp files, but have no idea why or how to change that.. Do you maybe know what I can do?

  Kind regards!
• Fab

  September 2021

  Hi @SQuestion,

  I think you're using an outdated version of Open Sesame. What version are you using?

  Since version 3.0, experiments are saved in .osexp instead of .opensesame (see https://osdoc.cogsci.nl/3.3/important-changes-3/#opensesame).

  I recommend you download the latest version. Version 3.3.10 just came out: https://forum.cogsci.nl/discussion/7440/opensesame-3-3-10-released-includes-osweb-1-4-0-and-rapunzel-0-5-29#latest

  In principle you should be able to open your old .opensesame file and read .osexp files.

  Kind regards,

  Fabrice.

  
• SQuestion

  November 2021

  Hi @Fab ,

  Although I asked my last question regarding this topic some time ago, I still have another problem with the questions I implemented.

  In my experiement, you can find a questionnaire at the bottom. My problem here is that pressing the "Shift"-key in the sketchpad (for each question) does not cause the letters to be "big" but rather the word "shift" is spelled out. This may confuse participants. Same thing happens with some other keys.

  Furthermore and probably even more disturbing is the fact that participants can not deleate the first letter or number they typed into the skechpad-response field. If there is only one letter/number in the answer field and a participant presses the backspace-key, a white screen occurs from which you can continue by pressing the space bar. If a participant typed in => 2 letters/numbers, it is possible to use the backspace-key to delete what is typed in (except for the first number/letter; then the white screen occurs).

  Is it possible to a) change that the keys like shift really function and not only spell out what they should do? Is it b) possible to implement that participants can also delete their first letter/number without the whole sketchpad "vanishing"?

  Experiment_exactFeedback.opensesame

  I attached my experiment.:)
• Fab

  November 2021

  Hi @SQuestion,

  I had a quick look at the questionnaire bit of your task. I noted that you're still using an outdated version of Open Sesame. Not sure that the version you're using includes the form objects but I suspect it does not. You'd make you life easier by using the latest version of OS and collecting your responses using the form_text_input object. No more playing around with canvases or having to deal with special keys like left shift etc.

  With your code as it is, the issue of special characters can be dealt with with more code. Basically, you want to adapt the code to catch cases where participants press keys like left or right shift. The same way to delete the last character from the resp variable when they hit backspace, you can delete the last n characters when they press, say, the left shift key. The number of characters to remove is the length of the string value of the key they pressed (e.g., "left shift" is 10 characters long).

  This is code you could use for each of the sketchpads in your questionnaire. Here, I modified the one for for "gender" question.

  from openexp.canvas import canvas
  from openexp.keyboard import keyboard
  my_canvas = canvas(self.experiment)
  my_keyboard = keyboard(self.experiment)
  resp = "" # Here we store the response
  while True:
                 # Get a keyboard response
                 key, time = my_keyboard.get_key()
                 # keyboard.to_chr() converts the keycode to a description,
                 # like 'space' or 'return'. If return is pressed the loop
                 # should be exited.
                 if my_keyboard.to_chr(key) == "space":
                                 break
                 # Handle backspace by removing the last character
                 if my_keyboard.to_chr(key) == "backspace":
                                 resp = resp[:-1]   
                 else:
                                 # The built-in chr() converts the keycode to a character,
                                 # like ' ' and '/'.
                                 resp += my_keyboard.to_chr(key)
                                 if key.isalpha() :
                                                 print("\n" + key +" is A LETTER.")
                                 elif key.isdigit() :
                                                 print("\n" + key +" is A DIGIT.")
                                 else :
                                                 print("\n" +key+ " is A SPECIAL CHARACTER.")
                                                 resp = resp[:-len(my_keyboard.to_chr(key))]
                 # Copy the canvas from a sketchpad called 'my_sketchpad' and
                 # overlay the response
                 my_canvas.copy(self.experiment.items["gender"].canvas)
                 my_canvas.text(resp)
                 my_canvas.show()   
                 print ("key: "+my_keyboard.to_chr(key)+" "+str(len(my_keyboard.to_chr(key)))+" chr:"+key)
  # Save the response
  self.experiment.set("gender", resp)
  

  In the code above, you can see that if the key pressed is not SPACE or BACKSPACE, the code will distinguish between letters, digits and other input. In the latter case, the number of characters from the last key is removed from the resp variable: resp = resp[:-len(my_keyboard.to_chr(key))].

  Regarding the issue of the blank screen, it has to do with the use of the copy function. You can see in the documentation that there is a warning of unpredictable behavior when using this function: https://osdoc.cogsci.nl/3.3/manual/python/canvas/#function-canvascopycanvas

  Warning:

  Copying Canvas objects can result in unpredictable behavior. In many cases, a better solution is to recreate multiple Canvas objects from scratch, and/ or to use the element interface to update Canvas elements individually.

  To be honest, I'm not sure how to go about solving that.

  My recommendation is to upgrade to the latest version of Open Sesame and make use of the form objects to implement the questionnaire part of your study. It'll work much better and it'll save you a lot of coding.

  Hope this helps.

  Fabrice.