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.
Best Answer: Grover Cleveland is the only U.S. president ever to serve two non-consecutive terms. Cleveland was a Democrat who had gained a reputation for efficiency and clean government during terms as mayor of Buffalo and then governor of New York. He was elected president in 1884, succeeding Chester A. Arthur.