This 15-question, free & research-validated instrument measures feeling of social interaction anxiety, as opposed to patterns of behavior that might arise from social anxiety.

Many of the methods suggested for becoming more interculturally competent rely heavily on the idea that there must be direct person-to-person interaction (whether physical or virtual), in order for skills to improve.  This can be anxiety-causing for some individuals; thus using this instrument paired with a debrief may be helpful for more introverted learners.