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Yes, but this is a way more useful explanation than what you get from
E-Basic help, which is as dry and difficult to traverse as Death Valley.<br>
<br>
Your solution is smarter & more economical than mine, too. I
suggested adding an attribute to a list to get it recognized, then
updating it with an inline object.<br>
<br>
Thanks for the Context lesson.<br>
<br>
Leisha<br>
<br>
Tony Zuccolotto wrote:<br>
<blockquote
cite="midB68F9C2FB5456441821E39FFF2FA50885401FF@exchange01.pst.local"
type="cite">
<pre wrap="">Robert,
You're very close to what you need to do. You do need to use an
attribute in the time limit box, but the part you're missing is that all
attributes exist in the experimental "context" and you need to get the
value you want to use into the context. The Context is a concept
unique to E-Prime and it constitutes a hierarchical/multi-leveled data
space which is separate from E-Basic variables (e.g. variables you would
declare with the Dim statement). The Context in E-Prime conceptually
represents all the "experimental data" that you care about and directly
dictates what gets written to the data file.
All attributes declared on List objects automatically get put into the
context when the List is run. Also, stimulus presentation objects will
insert items into the context after they run or at the end of
procedures, e.g. to add in dependent measures like Stimulus.RT,
Stimulus.ACC, etc.
You are free to put essentially any piece of useful data into context
via script and can do so with the following syntax.
c.SetAttrib "attributeName", value
for example...
Dim Dura As Long ' declare a variable in E-Basic for
computations
Dura = AveRT - 0.5*stddev ' do the computation
c.SetAttrib "Dura", Dura ' add the value of the computation into
the context under the specified name (the names used do not have to
match).
After you call c.SetAttrib and add something into the context then the
"[Dura]" syntax can be used on object properties and at runtime the
system will look up the value of the specified attribute.
When c.SetAttrib is called and an attribute already exists then the
attributes value will just be updated. If the attribute doesn't
already exist it will be created. Every new attribute you put in the
context it will automatically become a new column of data in the data
file.
If you need to get a value from the context via script the syntax is
value = c.GetAttrib( "attributeName" )
When you call c.GetAttrib the system will check the current level first
(e.g. Trial level) and if it can't resolve the reference it will move up
the next level of the hierarchy (e.g. Block level, then Session level)
until it finds the attribute. If an attribute can't be found you will
receive a runtime error.
For more information you should look in the E-Basic help system under
the Context object.
Hope that helps.
-Tony
Anthony P. Zuccolotto
President and Chief Executive Officer
Psychology Software Tools, Inc.
2050 Ardmore Boulevard
Suite 200
Pittsburgh, PA 15221-4610
Phone 412-271-5040
FAX 412-271-7077
Email <a class="moz-txt-link-abbreviated" href="mailto:anthony.zuccolotto@pstnet.com">anthony.zuccolotto@pstnet.com</a>
Internet <a class="moz-txt-link-freetext" href="http://www.pstnet.com">http://www.pstnet.com</a>
</pre>
<blockquote type="cite">
<pre wrap="">-----Original Message-----
From: <a class="moz-txt-link-abbreviated" href="mailto:eprime@mail.talkbank.org">eprime@mail.talkbank.org</a> [<a class="moz-txt-link-freetext" href="mailto:eprime@mail.talkbank.org">mailto:eprime@mail.talkbank.org</a>] On
</pre>
</blockquote>
<pre wrap=""><!---->Behalf
</pre>
<blockquote type="cite">
<pre wrap="">Of Robert F. Buzan
Sent: Tuesday, March 21, 2006 12:48 PM
To: <a class="moz-txt-link-abbreviated" href="mailto:eprime@mail.talkbank.org">eprime@mail.talkbank.org</a>
Subject: Variables in lists
I'm a fairly green E-Prime programmer and have encountered a problem I
can't
find an answer for. I'd appreciate any help that anyone can provide.
</pre>
</blockquote>
<pre wrap=""><!---->I'm
</pre>
<blockquote type="cite">
<pre wrap="">trying to create an experiment that limits the amount of time that
participants can respond. It's done in this way:
RT data is collected in the practice phase and the mean and standard
deviation
are computed. We then create a variable to be used for the allowable
response
duration on one of the later blocks, thusly: Dura = AveRT -
</pre>
</blockquote>
<pre wrap=""><!---->0.5*stddev.
</pre>
<blockquote type="cite">
<pre wrap="">This
works just fine.
Later, when I need to use this, I want to set the allowable response
</pre>
</blockquote>
<pre wrap=""><!---->time
</pre>
<blockquote type="cite">
<pre wrap="">for
the stimulus to which participants must respond to Dura. We've tried
putting
Dura directly into the timelimit box, but it must be an integer or an
attribute. We've tried putting [Dura] directly into the timelimit
</pre>
</blockquote>
<pre wrap=""><!---->box,
</pre>
<blockquote type="cite">
<pre wrap="">but
that is considered an attribute. We've created a separate attribute,
[MyTime], and populated that column with Dura (which, I believe, it
interprets
as a string) or with [Dura] (which is then an attribute). I think
</pre>
</blockquote>
<pre wrap=""><!---->I've
</pre>
<blockquote type="cite">
<pre wrap="">narrowed the problem down to this question: How do I use a variable
</pre>
</blockquote>
<pre wrap=""><!---->in a
</pre>
<blockquote type="cite">
<pre wrap="">list?
If that's the wrong question, does anyone have a suggestion for making
this
program limit response time to the value of Dura (Average RT minus
</pre>
</blockquote>
<pre wrap=""><!---->one-
</pre>
<blockquote type="cite">
<pre wrap="">half
the standard deviation)?
Thanks for your help.
Gratefully,
Robb Buzan
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
</blockquote>
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