Any multi-year, supervisory union wide, student data system requires local student IDs for consistent student identification throughout the student's school career.
When dealing with local student IDs it is essential that the numbers be unique and permanent.
Unique means that a number is assigned to one student and never used again for any other student forever. Permanent means that once a number is assigned to a student, the student retains the number and it never changes for any reason.
This is of the upmost importance when data is moved from one system to another. Imagine getting a list of students from a student information system to collect data in another system like AIMSWeb, an electronic grade book, VCAT, or any other student data system. If a student ID is changed in the student information system while the data is being collected, that data can not be imported directly back into the student information system because of the changed student ID.
Student names alone can not be depended on for this. They change often, nicknames are common, and two students can have the same name.
Student IDs must also be maintained when a student moves from one school to another. Data can be collected in the spring and not entered until the fall. If a student moved from one school to another during the summer, there is no easy way to know for sure if it is the same student unless the ID is maintained.
Student IDs are not student codes intended to give any additional information about a student. If a student ID is prefixed with a school code, it is so a unique ID can be created more easily. If each school puts a school number at the beginning when they enroll a new student, then they can be assured that the number is unique without consulting the other schools. Otherwise, all schools would have to coordinate the assigning of numbers. The leading number does not indicate in any way that a student belongs to a school. It is simply a way of insuring that numbers are unique across schools.