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Adding Standard Deviation to Summary Data File

EHP Lab — Fri, 03 Mar 2017 13:27:38 GMT

I am using the parametric go/no-go script from the Inquisit script library but I want to calculate the coefficient of variation for each level which requires having the standard deviation of response times for that level. To make it easy to compute, I would like to get the standard deviation as a variable in the summary data file for each participant. Is that possible? If so, what is the simplest way to achieve it? I spent a couple of hours researching the possible ways to do it, but I haven't written an inquisit script for a decade so I'm more than a little rusty, totally unfamiliar with version 5, and am hoping to do this as quickly and easily as possible!!

Thank you so much,
Amie

RE: Adding Standard Deviation to Summary Data File

EHP Lab — Fri, 03 Mar 2017 13:27:38 GMT

[quote]

[b]Dave - Friday, March 3, 2017[/b]

[quote]

[b]EHP Lab - Friday, March 3, 2017[/b]

[quote]

[b]Dave - Friday, March 3, 2017[/b]

[quote]

[b]EHP Lab - Friday, March 3, 2017[/b]

[/quote]

The easiest way is to add the observations (latencies) in trials of a given level to a <list> -- you could for example, set up a <list> per relevant level. You can then log the respective lists' standardeviation property to the data file(s).

[/quote]

Thank you for your quick reply. I have never used the <list> element before, do you know of any sample script which does what you are suggesting that I could pull from?

Thanks!
Amie

[/quote]

Here's a simple example to convey the idea and illustrate the proper syntax:

<expt>
/ blocks = [1=level1; 2=level2]
</expt>

<block level1>
/ trials = [1-10 = mytrial]
</block>

<block level2>
/ trials = [1-10 = mytrial]
</block>

<trial mytrial>
/ ontrialend = [
if (script.currentblock == "level1") list.level1_latencies.appenditem(trial.mytrial.latency);
]
/ ontrialend = [
if (script.currentblock == "level2") list.level2_latencies.appenditem(trial.mytrial.latency);
]
/ stimulusframes = [1=mytext]
/ validresponse = (57)
</trial>

<text mytext>
/ items = ("this is <%script.currentblock%>")
</text>

<list level1_latencies>
</list>

<list level2_latencies>
</list>

<summarydata>
/ columns = (script.startdate, script.starttime, script.subjectid, script.groupid, list.level1_latencies.standarddeviation, list.level2_latencies.standarddeviation)
</summarydata>

[/quote]

That's perfect. I ran it and it works. Thanks!

RE: Adding Standard Deviation to Summary Data File

Dave — Fri, 03 Mar 2017 12:24:46 GMT

[quote]

[b]EHP Lab - Friday, March 3, 2017[/b]

[quote]

[b]Dave - Friday, March 3, 2017[/b]

[quote]

[b]EHP Lab - Friday, March 3, 2017[/b]

[/quote]

Thank you for your quick reply. I have never used the <list> element before, do you know of any sample script which does what you are suggesting that I could pull from?

Thanks!
Amie

[/quote]

RE: Adding Standard Deviation to Summary Data File

EHP Lab — Fri, 03 Mar 2017 12:18:49 GMT

[quote]

[b]Dave - Friday, March 3, 2017[/b]

[quote]

[b]EHP Lab - Friday, March 3, 2017[/b]

[/quote]

Thank you for your quick reply. I have never used the <list> element before, do you know of any sample script which does what you are suggesting that I could pull from?

Thanks!
Amie

RE: Adding Standard Deviation to Summary Data File

Dave — Fri, 03 Mar 2017 12:10:35 GMT

[quote]

[b]EHP Lab - Friday, March 3, 2017[/b]

[/quote]