The ACT originally consisted of four tests: English, Mathematics, Social Studies, and Natural Sciences. In 1989, the Social Studies test was changed into a Reading section (which included a Social Studies subsection) and the Natural Sciences test was renamed the Science Reasoning test, with more emphasis on problem solving skills.In February 2005, an optional Writing test was added to the ACT, mirroring changes to the SAT that took place later in March of the same year. In the spring of 2015, the ACT will start to be offered as a computer-based test that will incorporate some optional Constructed Response Questions; the test content, composite score, and multiple choice format will not be affected by these changes. The test will continue to be offered in the paper format for schools that are not ready to transition to computer testing.