occasional skips

[Caren Frosch]

hm, that's interesting. Did you figure out a way around that problem? I 
suppose I could set the duration so it's long enough to ensure the 
participants reads it.
Caren

philippe goldin wrote:
> Uisng Epimre v2, we have also observed that on a slide set to infinite 
> time with a button press to terminate that slide, the slide will 
> sometimes automatically terminate (without a button press) and advance 
> to the next slide.  We have not been able to identify the source of this 
> irrgular problem.
> 
> philippe
> 
> 
> 
> At 05:27 PM 8/10/2007 +0100, Caren Frosch wrote:
> 
>> Leisha Wharfield wrote:
>>
>>> Stimulus duration = infinite, Time limit = same as duration, End 
>>> action = terminate?
>>
>>
>> yes.
>>
>> I have a feeling it could have something to do with the pre-release on 
>> the slide that appears prior to the skipped slide. Doruk mentioned 
>> something about it and when I read up about it some more I realised 
>> that the fact that I have pre-release on a slide which is terminated 
>> by response input could be a problem (though it didn't specifically 
>> say that this could cause skipping). I've taken the pre-release out 
>> and will have to see if it happens again. As the skipping has never 
>> happened to me I need to wait for my next participant on Tuesday.
>>
>> Thank you for your help.
>> Caren
>>
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>>> Caren Frosch wrote:
>>>
>>>> I ran a few more participants today. For the first one everything 
>>>> ran smoothly. For the second one, the slide that should be presented 
>>>> at the end of the practice trial skipped. E-prime recorded the 
>>>> following data for that trial:
>>>> RT: 0
>>>> RESP: (blank)
>>>> OnsetTime: 0
>>>>
>>>> To me that looks like it just skipped, but I cannot work out why. 
>>>> Any suggestions?
>>>>
>>>> Thanks,
>>>> Caren
>>>>
>>>>
>>>>
>>>> Caren Frosch wrote:
>>>>
>>>>> Hi Leisha,
>>>>> I hadn't been recording any data for those trials as they are only 
>>>>> instructions trials, but I've switched it on now. For the last 
>>>>> participant where it happened it recorded a RT of 0. The stimulus 
>>>>> duration is 'infinite' and the allowable response for this slide is 
>>>>> not an allowable response on the task trials.
>>>>>
>>>>> I'm testing a few more people today. I'll see if I can shed some 
>>>>> more light on the issue.
>>>>>
>>>>> Thanks for your input!
>>>>> Caren
>>>>>
>>>>>
>>>>> Leisha Wharfield wrote:
>>>>>
>>>>>> "It's also not possible that participants are accidentally hitting
>>>>>> the key that moves the slide on as I deliberately chose a key away
>>>>>> from the keys they are using to respond to the trials (and I don't
>>>>>> tell them which key it is)."
>>>>>>
>>>>>> Do the data bear this out? There are no entries for notaskproc; it 
>>>>>> never launches? Have you tried, during testing, prematurely 
>>>>>> hitting the key that moves the slide on to see what happens? In my 
>>>>>> experience, if there is an unexpected way to proceed through the 
>>>>>> experiment, subjects will find it (& that's probably a good thing, 
>>>>>> because it leads to refinement).
>>>>>>
>>>>>> The key that moves the slide on should only be an allowable 
>>>>>> response in notaskproc, therefore hitting it prematurely should do 
>>>>>> nothing. Is this the case?
>>>>>>
>>>>>> Leisha Wharfield
>>>>>> Decision Research
>>>>>> Eugene, Oregon, USA
>>>>>>
>>>>>> Caren Frosch wrote:
>>>>>>
>>>>>>>
>>>>>>> I'm running an experiment where I have divided a list into four 
>>>>>>> blocks, that is, the list consists of 160 trials and after 40 
>>>>>>> trials it leaves the list to run another procedure which consists 
>>>>>>> of one slide where participants are told whether or not to 
>>>>>>> generate random numbers during the next block (actually one of 3 
>>>>>>> procedures: 'taskproc' 'notaskproc', 'endproc'). It's all been 
>>>>>>> running fine. But I have found that for some participants it 
>>>>>>> occasionally skips this step and they therefore end up doing one 
>>>>>>> big block (consisting of 80 trials). Has anyone experienced this 
>>>>>>> kind of thing before and do you have any suggestions as to what 
>>>>>>> it might be? Could it be a hardware problem (e.g. the keyboard)?
>>>>>>>
>>>>>>> Any suggestions would be much appreciated as I just can't figure 
>>>>>>> out why it's doing it. When I run through the experiment myself 
>>>>>>> it's always fine. It's also not possible that participants are 
>>>>>>> accidentally hitting the key that moves the slide on as I 
>>>>>>> deliberately chose a key away from the keys they are using to 
>>>>>>> respond to the trials (and I don't tell them which key it is).
>>>>>>>
>>>>>>> Thank you,
>>>>>>> Caren
>>>>>>>
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>> -- 
>> Dr. Caren Frosch
>> Research Fellow
>> School of Psychology and Clinical Language Science
>> University of Reading
>> Earley Gate
>> Reading
>> RG6 6AL
>>
>> E-mail: c.frosch at rdg.ac.uk
>> Phone: 0118 3785538
>>
> 
> 
> **************************************************************
> Philippe Goldin, Ph.D.
> Department of Psychology
> Stanford University
> Jordan Hall, Bldg. 420, Room 126
> Stanford, CA 94305
> 
> Tel: 650-723-5977
> Fax: 650-725-5699
> E-mail: pgoldin at stanford.edu
> website: Clinically Applied Affective Neuroscience
> http://www-psych.stanford.edu/~caan/
> 
> 
> 
> 
>