Though there is no single, thoroughly researched and widely practiced âmodelâ of the RTI process, it is generally defined as a three-tier (or three-step) model of school supports that uses research-based academic and/or behavioral interventions.The Three-Tier Model is described below.hough there is no single, thoroughly researched and widely practiced âmodelâ of the RTI process, it is generally defined as a three-tier (or three-step) model of school supports that uses research-based academic and/or behavioral interventions. The Three-Tier Model is described below.
Franklin Delano Roosevelt is the US President who served the greatest number of years in office. He was President from 1933 to 1945, which was 12 years. Currently, Preside â¦ nts are constitutionally limited to two consecutive terms, adding up to only 8 years.
One President Served More Than Two Terms. The only president to serve more than two terms was Franklin D. Roosevelt. In 1940 he won the election for his third term. Four years later in 1944, he ran again. He became the only president to be elected to a fourth term. However, he was president for only a year into his fourth term before he suffered from a cerebral hemorrhage and passed away.