AUGUSTA — Maine officials say a new Harvard study ranking Maine near the bottom for improvement of student test scores serves as a wake-up call that more must be done to improve public schools.

The study, “Achievement Growth: International and U.S. State Trends in Student Performance,” put Maine second from the bottom among states for test score improvement between 1992 and 2011.

Gov. Paul LePage on Wednesday said he’s calling on the education commissioner, school administrators and teacher unions to implement new educational practices focused on student learning.

While Maine ranks above the national average in school test scores, LePage said he’s disappointed that test scores have shown little improvement in the past 20 years.