Missouri students scored lower on standardized test for most subjects this year, leaving state education officials searching for answers as to why.

Statewide figures released Tuesday show that fewer students scored "proficient" or better this year on tests for communication arts, mathematics and science, compared with last year. The only overall improvement was in social students.

The decline comes after several years of general improvement in student test scores.

The State Board of Education was meeting Tuesday to discuss the test results. Several explanations were offered, including the use of new test questions and the loss of instructional time this past school year because of severe winter weather.

Staff for the Department of Elementary and Secondary Education said the transition to new Common Core educational standards may also have played a role, as it could have created uncertainty among teachers and administrators and general public unrest.

The statewide figures show the percentage of students scoring "proficient" or "advanced" in mathematics declined in third, fourth, fifth, sixth, and seventh grades, rising only for eighth-graders on the tests that were administered this past school year.

In communication arts, the percentage of students scoring "proficient" or "advanced" fell in all of those grades except seventh.

The state also administers end-of-course exams for high school students. Those scores fell in Algebra 1, English 1 and Biology but rose in Algebra 2, Geometry, English 2, Government and American History.

The MAP test is given to students in grades three through eight annually. Test results are used to develop school and district-level Annual Performance Reports. The APR is used to determine a district’s accreditation classification, which is based on five areas: Academic achievement, subgroup achievement, high school/college/career readiness, attendance and graduation rate. These reports are to be released Aug. 29.

Winter weather over the last school year could be to blame for the lower scores as well. According to DESE, more than 23 percent of all Missouri districts reduced their actual days of attendance by 10 or more days. Although its analysis shows no definite pattern for districts with a large number of snow days, scores from individual districts may have been affected by make-up schedules.

Examiner reporter  Brandon Dumsky contributed to this article.