occasional skips

[Leisha Wharfield]

Stimulus duration = infinite, Time limit = same as duration, End action 
= terminate?

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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-- 
“And then many things happened at the same moment.”