occasional skips

[Caren Frosch]

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
>>>
>>>
>