Response to Intervention or RTI for short is defined by John Hattie as “a multi-tier approach to the early identification and support of students with learning and behavior needs. The RTI process begins with high-quality instruction and universal screening of all children in the general education classroom (Tier 1). Struggling learners are provided with interventions at increasing levels of intensity to accelerate their rate of learning. Those not making progress are then provided with increasingly intensive instruction usually in small groups (Tier 2). If still no progress, then students receive individualized, intensive interventions that target the students’ skill deficits (Tier 3).” 

That being said, the RTI model is actually quite complicated and I often see people attempting to simplify it as a professional learning model, a formative assessment model, or as an alternative to traditional special education models. However, I would view these positions as reductive. I was actually trained as an RTI teacher and it was through RTI that I was actually originally exposed to the idea that teaching could be a science. According to my personal experience, and RTI training I would define RTI as an action research framework that has:

-Teachers collectively plan instruction and assessments

-Monitor student success via formative assessment and data collection

-Collectively mark assessments

-Collectively plan intervention for students not meeting learning expectations, via tiered instruction. 

In my opinion this framework attempts to leverage the effects of collective-self efficacy, formative assessment, data-collection, and individualized instruction. Of course the most central tendency of this framework is that students receive more instruction based on their needs. The core of the classroom is labeled tier 1 and receives the standard core curriculum. Students who are struggling a little are given some additional instruction and support and labeled tier 2. And students who are struggling a lot are labeled tier 3 and given the most support. This is meant to differ from regular special education in that these labels and groupings are not static, they are fluid. Meaning, if a student is especially struggling with a particular learning goal, they are given tier 3 instruction. Moreover, if a learning disabled student is not struggling with a specific learning goal, they are not necessarily given tier 3 instruction during the instructional period of that learning goal. 

The fluid groupings of the RTI system is often the aspect that gets most criticized, as there is the concern that a student with a Dyslexic need, might receive less tier 3 instruction than would happen within a traditional special education system. And of course, students diagnosed with Dyslexia should absolutely be receiving additional tier 3 instruction. However; I personally like the fluid groupings for two reasons. Firstly, I believe they help promote a growth mindset, and avoid making students feel labeled; the students receive tier three instruction, they are not tier three students. Meaning the same students will not always necessarily be receiving tier 3 instruction. Secondly, I think this approach can lead to more individualized instruction, as the instruction is about specific learning needs, not specific students.

For example, let's say we set learning the vowel sounds as a learning goal for the unit. The students who make the slowest progress in learning those sounds, will receive the most instruction, until they learn those sounds at which point the student is bumped back into tier one instruction. This ensures that additional instruction is always specific to the curriculum goals and the specific needs of students. Moreover, as the instruction is dependent on the students knowledge of individual curriculum, the students receiving the additional instruction will change with each unit. This system can lead to less students receiving tier three instruction on average, but if done correctly, it should not lower learning results. Indeed the research would suggest that most students benefit from this system, as I will show below. Moreover, I think it is important to note, this system does not necessitate students not receiving additional instruction specific to learning disorders or needs. I believe schools can both use an RTI system and mandate dyslexic students receive additional support. I think it would be a false dichotomy to say that the choice has to be one or the other, of course this is not to say that there are not schools in which that false dichotomy has been contrived. 

Of course, as always my default position in determining the efficacy of a pedagogical strategy is to rely on the meta-analytic data. To the best of my knowledge, there have been 5 meta-analyses on RTI. All of them showed strong results. However, two of them were not peer reviewed. And most of them included inflating results. I have graphed these effect sizes below; however, someone may notice that my reported effect sizes are different from the ones Hattie reports on. This difference is because where possible, I have removed the inflationary results.