occasional skips

[Caren Frosch]

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










> 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