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Brilliant. Thanks, Ben. <br>
<br>
Ben Robinson wrote:<br>
<blockquote cite="mids5266791.074@mprc.umaryland.edu" type="cite">
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<div>one way to do this, without any scripting, would be to have
several lists.</div>
<div>1st list: one item - not an X</div>
<div>2nd list: 7 items, including your X, selected randomly</div>
<div>3rd list: 1 item - not an X</div>
<div> </div>
<div>each of the 3 lists would have the same nested list, call it
FontsList, with 4 items in it (32, 72, and two other font sizes).
these 4 font sizes would be in a column called FontSize, and items from
FontsList would be randomly selected.</div>
<div> </div>
<div>then, within your procedure, the TextDisplay item presenting
your stimuli would reference the column [FontSize] such that each
presented stimulus would pull a fontsize at random from your FontsList.</div>
<div> </div>
<div>make sense?</div>
<div> </div>
<div>SessionProc</div>
<div> List1 (1 item, not an X, with FontsList nested)</div>
<div> PresentationProc</div>
<div> List2 (7 items, including X, with FontsList nested)</div>
<div>
<div> PresentationProc</div>
<div> List3 (1 item, not an X, with FontsList nested)</div>
<div>
<div> PresentationProc</div>
</div>
</div>
<div> </div>
<div>ben robinson<br>
<br>
>>> "Mark Chan" <a class="moz-txt-link-rfc2396E" href="mailto:mr.mark.chan@gmail.com"><mr.mark.chan@gmail.com></a> 10/6/2006 12:56
AM >>><br>
</div>
<div style="color: rgb(0, 0, 0);">'m trying to design a study with
Pseudo-Random presentation of stimuli.<br>
<br>
Basically this is what i'm looking at:<br>
<br>
<ul>
<li>I'll be presenting 9 different objects in 25 blocks<br>
</li>
<li>There is a target object, which we will call "X".
</li>
<li>I need "X" to appear once within each block<br>
</li>
<li>"X" cannot re-appear back to back.<br>
i.e. <span style="font-style: italic;">end of block 1</span>, we
have... stimuli, stimuli, TARGET, <span style="font-style: italic;">start
of block 2</span> TARGET, stimuli, stimuli...this cannot occur
</li>
<li>It would be preferable if there were at least 3 stimuli between
TARGET presentation. </li>
<li>We do not wish to have repeats of stimuli and target within
each block. <br>
</li>
</ul>
Also, i was wondering if you could have the font sizes change randomly
(4 different sizes) between stimuli. Say first stimuli, font = 32, next
stimui = 72, etc.<br>
<br>
Any ideas?<br>
<br>
Thanks! </div>
</blockquote>
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