Are Individual Differences in Response to Intervention Influenced by the Methods and Measures Used to Define Response?

• Response to Intervention (RTI) has been promoted as a valid method for identifying learning disabilities, but questions remain about how it should be used.
• This study examined how individual student differences predicted response to a reading comprehension intervention using different measures as well as different definitions of “response.”
  • The definitions of “response” were: 
    • final status relative to assessment cut-scores (i.e., above or below) and 
    • growth from pre- to post-treatment.

When response was measured by final status, students with higher pretreatment scores on measures of expressive vocabulary, nonverbal IQ, teacher ratings of attention, and reading comprehension were more likely to be classified as responsive to intervention.

When response was measured by growth, students with lower pretreatment comprehension scores were more likely to be classified as responsive to intervention.

According to the authors, these findings suggest “response” is strongly context-dependent, raising questions about the validity of RTI as a means of disability identification.