Dr. aba is conducting a study to see whether there is a relationship between birth order and shyness. to assess participants' shyness, dr. aba uses a questionnaire: a score of 0-5 on the questionnaire indicates extreme shyness; 6-10, moderate shyness; 11-15, normal shyness; 16-20, moderate lack of shyness; and 21-25, extreme lack of shyness. this use of the questionnaire establishes a(n) of shyness.