In the case of code-switching, the first factor is the average switching level per utterance, as calculated by inserting the C u given by Equation 6 into the average of Equation 5, while the second factor is the frequency of utterances that contain any code-switching (i.e., utterances with C u > 0).
arriving at Equation 10: where S is the number of utterances that contain codeswitching (0 ≤ S ≤ U ), and w s the relative weight attached to the switching frequency.