Accuracy of the last response for the specified element.
<block> <expt> <likert> <openended> <slidertrial> <trial>
A value of 1 indicates incorrect, 0 indicates correct).
The following displays the value of error in a text stimulus:
<text sometext>
/ items= ("error = <% trial.sometrial.error %>")
</text>
The following displays the value of error in an instruction page:
<page somepage>
error = <% trial.sometrial.error %>
</page>