Serial 3s Task - Cross-Examining Psych Doctors, Tip #117

     When performing a Mental Status Examination during a psychological evaluation, the doctor may choose to have the patient count backward from 20 by 3s as a measure of their concentration.  This task is called a serial 3s task and can be done relatively quickly during a face-to-face interview.  The patient’s performance on a serial 3s task is a measure of concentration.  When a doctor chooses to use a serial 3s task to measure the patient’s concentration, it is imperative that they describe their observational data in their report of their Mental Status Examination.