Millisecond Forums » Millisecond Forums » Inquisit 4 » Clarifying Output Variable Names in Change Blindness TaskInstantForum 2017-1 FinalMillisecond Forumshttps://forums.millisecond.com/Millisecond ForumsThu, 30 Apr 2026 20:24:57 GMT20Clarifying Output Variable Names in Change Blindness Taskhttps://forums.millisecond.com/Topic15437.aspxI have some data from the Change Blindness task (<a href="http://www.millisecond.com/download/library/ChangeBlindness/)">http://www.millisecond.com/download/library/ChangeBlindness/)</a><br/><br/>I understand the task and what it's measuring but I cannot decode the variable names Inquisit in outputting nor can I find any documentation explaining the variables.&nbsp;<br/><br/>For each trial I get the following column names:<br/>values.prechange3_hits, values.prechange3_fas, expressions.prechange3_diff, <br/>values.postchange3_hits, values.postchange3_fas, expressions.postchange3_diff<br/><br/>I understand the pre and post trials, "diff" is just "hits - fas".&nbsp;<br/>I cannot figure out what "hits" &amp; "fas" are though.&nbsp;<br/>Hits looks like it could be the serial position of the item that was removed/replaced and fas is the subject response, correct of false. However Fas occasionally takes the value of 2 (almost always 0 or 1 otherwise). These aren't intuitive, abbreviations or acronyms though which makes me think it must be something else.&nbsp;<br/><br/>Looking for an "AHA" moment :)<br/><br/><br/>Fri, 30 Jan 2015 16:28:50 GMTskotturi01RE: Clarifying Output Variable Names in Change Blindness Taskhttps://forums.millisecond.com/Topic15438.aspxIf you open the script in Inquisit Lab (or any other text editor -- it's just a text file), you will find all of this documented throughout the comments included in the script. The detailed documentation for the data output starts at line 505.<br/><br/>A relevant excerpt:<br/><br/>/postchange_FAs:&nbsp; sums up hits/False Alarms (FAs) for prechange and postchange recognition<br/>/prechange3_diff: &nbsp; difference in values.prechange_hits - values.prechange_FAs for array number = 3 (same for all array numbers)<br/>/postchange3_diff: difference in values.postchange_hits - values.postchange_FAs for array number = 3 (same for all array numbers)<br/><br/>Hits and False Alarms are standard technical terms in Signal Detection Theory. See e.g. <a href="https://en.wikipedia.org/wiki/Detection_theory#Psychology">https://en.wikipedia.org/wiki/Detection_theory#Psychology</a><br/>Fri, 30 Jan 2015 16:28:50 GMTDave