INSTRUCTOR WITH INST STUDENT DSNDS BELOW ASSIGNED ALT ON ILS APCH.

Narrative

WHILE GIVING INST INSTRUCTION TO AN INST RATED PLT ON AN IFR FLT PLAN WE WERE TOLD BY NY APCH TO INTERCEPT AND TRACK INBOUND ON THE INITIAL APCH BEARING OF THE NDB 23 AT MMU. THE STUDENT BEGAN A RAPID DSCNT BELOW 3000 FT TO 2400 FT ENRTE TO 2000 FT (THE INITIAL ALT). BY THE TIME I CAUGHT AND RECTIFIED THE MISTAKE (WE WERE NOT YET CLRED FOR THE APCH AND SHOULD HAVE MAINTAINED OUR LAST ASSIGNED ALT OF 3000 FT) NY APCH HAD POINTED IT OUT TO US. THE PROBLEM WAS FURTHER COMPLICATED BY THE STUDENT'S INABILITY TO ADMIT TO AN ERROR ON MY VERBAL INSTRUCTIONS TO CLB. THE STUDENT MOMENTARILY ARGUED WITH MY INSTRUCTIONS FORCING ME TO PHYSICALLY TAKE CTL OF THE ACFT UNTIL; OR AT THE SAME TIME AS NY APCH COMMENTED. THE STUDENT THEN BECAME HUMBLE AND RELINQUISHED CTL OF THE ACFT. THE HUMAN PERFORMANCE FACTORS INVOLVED WERE POOR COCKPIT RESOURCE MGMNT SKILLS ON THE PART OF THE STUDENT AND A SLOW CORRECTIVE ACTION ON THE PART OF THE INSTRUCTOR. ALL WAS COMPLICATED BY THE STUDENT'S LACK OF UNDERSTANDING OF THE CTLR'S LAST INSTRUCTIONS.