As to matters subject to the authority of the Secretary, the Secretary periodically shall conduct investigations and, as necessary, visits to various units to determine: the enforcement and effect of this Division I and the regulations adopted under it; the conduct of employees in the State Personnel Management System; the nature, tenure, and compensation of all positions in the State Personnel Management System; the appropriateness of position classifications by appointing authorities; whether the duties performed by an employee conform to the duties listed for that employee's class; the methods of administration of the State Personnel Management System; and any other information that might help the Secretary to administer this Division I. In conducting an investigation under this section, the Secretary may require any employee in the State Personnel Management System to appear before the Secretary or the Secretary's designee and give evidence.