 element of this list must have the same number of repeated measures as specified in <code>sg_var_list</code> when creating the sudden gains data set.</p></dd>


<dt>sg_session_n_var_name</dt>
<dd><p>String, specifying variable name that contains information about the pregain session number.
If the sudden gains data set was created using the suddengains R package, the default argument "sg_session_n" should be used.</p></dd>


<dt>extract_measure_name</dt>
<dd><p>String, if <code>extract_var_list</code> is a