From “SI” to “ASI”: Why The Distinction is Important

In the past, the term "Sensory Integration (SI)" was often used in a non-specific way. Today, it's clear: not everything referred to as "Sensory Integration intervention" adheres to the principles developed by Dr. A. Jean Ayres. To create clarity in this regard and, above all, to protect consumers, Dr. Ayres' descendants have registered the trademark for the term "Ayres Sensory Integration® (ASI)."

Parents often spend a lot of money on a therapy they believe to be Ayres Sensory Integration. Until it turns out that it isn't: the therapist doesn't even have completed SI training, the assessment doesn't meet the requirements, the room doesn't meet the criteria... The therapy may have helped— a little, somewhere and somehow —but it wasn't as targeted and effective, coherent, replicable, and evidence-based as occupational therapy (OT) based on the ASI approach (OT-ASI), if carried out with fidelity to the core principles of the approach.

The name "Sensory Integration" appeals to many: SI is the third most sought-after therapy approach for children. Many want to ride this wave, but without doing the necessary preparatory work to offer the quality these kids and families deserve.

There is no financial interest behind the name protection, merely the desire to protect the integrity of Dr. Ayres' life's work. ASI is a scientific theory that makes certain claims and allows for predictions about effects and developments. Both the assessment tools and the complex, interactive therapy approach are based on Dr Ayres' theory with its specific core principles for intervention that are defined and verifiable in a dedicated Fidelity Measure (ASIFM; Parham et al., 2007, 2011)).

More on the background of the name protection and what is meant by ASI in the article “Understanding Ayres Sensory Integration” by Smith Roley et al. (2017) in AOTA's OT Practice Journal.

What is The ASI Fidelity Measure (ASIFM)?

The ASIFM is a standardized observational instrument developed and validated by Parham et al., 2007, 2011, and Schaaf et al., 2014. Trained raters can use it to determine whether an intervention truly adheres to ASI principles. This is particularly crucial in effectiveness research. For decades, investigators have lumped together all sorts of things related to the senses under the title of "testing the effectiveness of SI therapy." The results were—unsurprisingly, but repeatedly sobering and a setback for SI—always mixed at best. It was only the groundbreaking article by Jane Case-Smith (2014) that made the clear distinction between occupational therapy based on the ASI approach (OT-ASI) and sensory-based interventions (SBIs) which we still use today. Since then, effectiveness research has taken a drastically positive turn in favor of ASI.

Tip if you're reading effectiveness research articles: Since 2007, valid statements about the effectiveness of ASI can only be made by studies that have used the ASIFM to assess the methodological fidelity of the intervention under study. Therefore, if you don't find any mention of the ASIFM in an article about an effectiveness study on ASI, you don't need to bother reading the results any further. The quality of the study is too weak to trust the results.

Why is Methodological Rigor so Crucial?

Only when therapy is truly conducted according to ASI principles is it effective and efficient. With the help of ASIFM, we can eliminate studies that don't actually test ASI or adhere to the core principles. This creates a robust evidence base that also provides guidance in practice.

“Adherence to the principles of Ayres Sensory Integration®

using Fidelity Measure is the key to assessing the effectiveness of the intervention and to ensure scientifically sound treatment results

to achieve." - Roseann Schaaf, 2018

What is The 8-Step Process of ASI Therapy (OT-ASI)?

In addition to methodological adherence based on the ASIFM criteria, adherence to the manualized approach is crucial for an intervention to claim to be evidence-based ASI therapy.

The eight-step process for ASI was developed and presented by Roseann Schaaf and is published in the ASI Therapy Manual (Schaaf & Mailloux, 2015). The DDDM describes how the intervention process starts at the participation level, followed by a comprehensive assessment at the level of bodily functions, the generation of hypotheses regarding whether and how the identified sensory integration problems can explain the difficulties, the development of therapy goals, finding distal and proximal outcome measurements, defining conditions of the intervention, and finally, the implementation of the therapy.

Evidence: What Does Research Say Today?

The ASI effectiveness research from 2010 to 2025 shows:

• All studies using ASIFM report moderate to strong effectiveness of ASI, particularly in autistic children and children with sensory processing difficulties.

• Systematic reviews and meta-analyses (e.g., Gallegos-Berrios et al., 2025; Schoen et al., 2019; Schaaf et al., 2018) confirm that ASI leads to significant improvements in adaptive behavior, in the achievement of individual daily goals, and in sensory-related outcomes – provided the intervention strictly adheres to the ASI principles.

• RCTs from different countries (e.g., Chan et al., 2023; Omairi, 2022) show consistent, replicable results.

What Does This Mean in Practice?

• Use the term “Ayres Sensory Integration® (ASI)” if you refer to the original, evidence-based concept.

• In training courses, literature and practice, make sure that the ASIFM is mentioned as a quality feature.

• The effectiveness of ASI is now well documented – but only if the method is implemented with high fidelity.

Sources & further reading:

• Smith Roley, S. (2017): “Understanding ASI”

• Parham, LD, et al. (2011): Development of the ASIFM

• Gallegos-Berrios, S., et al. (2025): Systematic review of ASI

• Schoen, SA, et al. (2019): Systematic review of ASI in autism

• Schaaf, RC, et al. (2018): Effectiveness of ASI

• Factsheet Evidence for ASI 2010–2025

FAQ: Frequently asked questions about SI and ASI

Finally, I would like to address the most frequently asked questions on this topic:

1. What is the difference between “SI” and “ASI”?

The process of sensory integration is a general term for the processing and integration of sensory stimuli. ASI (Ayres Sensory Integration®) refers to the scientific theory of Dr. A. Jean Ayres, which goes far beyond this neurophysiological process, and the therapeutic approach derived from it, which uses clearly defined principles and a Fidelity Measure (ASIFM) for quality assurance.

2. How do I know if a therapy is really carried out according to ASI?

Make sure the therapy adheres to the ASI Fidelity Measure (ASIFM). This means the intervention follows Ayres' original principles, is individually tailored to the child, takes place in a purposefully designed environment, and is delivered by appropriately trained therapists.

3. For which children is ASI particularly suitable?

Research shows that ASI is particularly effective for children with autism spectrum disorder and/or sensory processing difficulties. Children with developmental delays or motor coordination disorders can also benefit if the method is implemented with high fidelity.

4. Is there scientific evidence for the effectiveness of ASI?

Yes! Numerous randomized controlled trials and systematic reviews (see sources above) demonstrate moderate to strong effectiveness of ASI—provided the intervention is conducted according to the original principles and with ASIFM.

5. How can I learn true ASI myself?

There are 4 accredited programs for English speakers on the website of the International Council for Education in ASI (ICE-ASI), ice-asi.org. The leading program taught at 40 countries around the world is from CLASI California, and parts of this program are embedded in all other ICE-ASI accredited programs such as those from SAISI, South Africa, ASIWise, UK & Ireland, and GSIÖ for Austria and the German speaking countries. See: www.ice-asi.org