Responsiveness to Intervention (RTI) is widely understood as representing a multilevel framework that integrates assessment and instruction to provide strong early intervention and valid methods of disability identification. There are currently many approaches to RTI, which are creating confusion among educators as they try to conceptualize, design, and communicate about it. To address this problem, we introduce a general RTI framework consisting of three levels, each of which is distinctive in terms of purpose, intensity of instruction, and professional responsibilities. "Primary prevention" refers to instruction delivered by general educators. "Secondary prevention" may be conducted by paraprofessionals--supervised by reading specialists, school psychologists, or special educators--who implement validated instructional protocols in small-groups. "Tertiary prevention"--the most intensive level of instruction--is individualized and relies on ongoing progress monitoring and a recursive, teach-assess-teach process that leads to inductively developed effective programs.