remember samples from list between participants

Sun May 18 09:29:25 UTC 2014

Hi Leon,

If I understand your question correctly, you would like EPrime to remember
which items are left 'unused' from a previous run (i.e. after closing the
program and restarting it?) I don't know in what way this would be *basic
functionality *because non of the paradigm development software package I
know, can do such a thing, but perhaps you were mislead by the option *'**reset
sampling at the beginning of each run'*. That option only effects
re-initialization of a list when it is played again in an *ongoing *experiment.
For example: a trial list that is used in a block design will be re-used in
each block. The trial list will normally be reset at the start of every
block when *'**reset sampling at the beginning of each run'* is checked.
Resetting a List object means: filling the *factorspace* again using the
List attributes and properties, and restart sampling.

To have a persistent *factorspace* that survives a restart of the
experiment, you would have to use inline script that implements some kind
of smart initialization of the List object. There are several examples
available that demonstrates how you can populate a list object using inline
script, so that should not be too complicated. However, you probably won't
find an example that uses the state of a previous run, so that requires
some thoughts. The most straightforward method is to create a file at the
end of experiment and fill it with the required information for the next
run (i.e. an enumeration of the unused items). Perhaps this can be done by
adding the List object at the end of you experiment to play the 'leftover'
items, but instead of actually presenting the stimuli, you could use a
procedure with an inline script to write the relevant information to a
file. This file should then be used at the next run of the experiment.
Perhaps it would be possible to use the option to fill a List object with
the contents of an external text file. This requires you to create a file
in a specific tab-delimited format, but it would save the trouble of
creating inline script that populates the List. From a programming point of
view, this method seems a very efficient way which requires not so much
inline script.

Alternatively, you could read the contents of a previous output file (the
logged experiment output that was saved as txt-file) and scan it to figure
out which stimuli were already used. Scanning the text-file probably requires
a larger piece of inline script. To simplify things, it should also be
possible to use a similar technique as described in the previous method:
include the list again at the end of the experiment to explicitly log the
items that were not used before, without actually presenting the stimuli.

Unfortunately I have no example code available, so you will have to try to
implement this yourself.

Best
Paul

On 17 May 2014 17:40, Leon van Rijswijk <vanrijswijk.leon at gmail.com> wrote:

> Hello everyone,
>
> I have been puzzling over this for a couple of weeks now, but I do not
> seem to be any closer to a solution. The problem is that I want E-Prime to
> exhaust a particular list over multiple participants without selecting
> samples that have already been selected for previous participants. I will
> try to break down the problem in a simplified version of the real
> experiment I'm designing.
>
> Suppose I want to present one stimulus at various stimulus presentation
> times. I have nine different presentation times in a nested list under the
> stimulus, but I do not want one participant to view my stimulus for more
> than three times. I thus only present the stimulus three times for each
> participant. For the first participant it randomly selects three stimulus
> presentation times from the nested list (which is set with options: reset
> sampling (all samples (9)), reset sampling at the beginning of each run is
> unchecked, exit list after 1 cycle (9 samples)). Now, for the second
> participant I want to randomly select from the six presentation times that
> have not been selected previously and for the third participant I want to
> randomly select the remaining three stimulus presentation times. To me this
> seems like basic functionality but whatever I have tried I cannot get this
> to work properly. It just seems to reset the sampling once the experiment
> closes.
>
> Any ideas will be greatly appreciated!
>
> Cheers,
>
> Leon
>
>
>  --
> You received this message because you are subscribed to the Google Groups
> "E-Prime" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to e-prime+unsubscribe at googlegroups.com.
> To post to this group, send email to e-prime at googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/e-prime/ce6e4642-ab64-463d-8df0-43bcd773c15e%40googlegroups.com<https://groups.google.com/d/msgid/e-prime/ce6e4642-ab64-463d-8df0-43bcd773c15e%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
> For more options, visit https://groups.google.com/d/optout.
>

-- 
You received this message because you are subscribed to the Google Groups "E-Prime" group.
To unsubscribe from this group and stop receiving emails from it, send an email to e-prime+unsubscribe at googlegroups.com.
To post to this group, send email to e-prime at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/e-prime/CAKAdR-txGE46SqdUwYQkrBT4cpRDBo%2Bjf7d71izr5M5m6HNyLg%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listserv.linguistlist.org/pipermail/eprime/attachments/20140518/5ab9c996/attachment.htm>