Assessing School-Level RTI Implementation for Reading: Development and Piloting of the RTIS-R

Few studies have examined Response to Intervention (RTI) implementation adherence at the school level. Although tools designed to assess the implementation of RTI exist, the technical properties have not been rigorously documented, and psychometric techniques now being used to develop instrumentation appear not to have been used. The purpose of this preliminary study was to address this gap by developing the RTI Implementation Scale for Reading (RTIS-R). The instrument was developed based on theory, and items were refined based on data from expert reviews and cognitive interviews. Data were collected from 53 principals and school psychologists implementing RTI in 33 schools in a Midwestern state. Rasch analysis was used to examine and refine the instrument; it also facilitated the computation of equal interval item measures and person measures. Results suggest that the instrument is rigorous and has strong reliability. Interesting trends in responses emerged, which reveal an ordering of item difficulty that matches that predicted from theory. Implications of these findings for research and practice are discussed.