In considering the issue of evidence-based practice (EBP), we take on a deceptively simple question—what counts as “evidence” of effectiveness of approaches in supporting the communication of nonspeaking autistic individuals? Beneath that question lies a deeper and more contentious issue—how definitions of acceptable evidence shape whose voices are heard, whose abilities are recognized, and which approaches are considered credible.
When we apply these questions to nonspeaking autistic individuals, the stakes become especially high. For decades, debates about assisted communication (AC) methods—particularly those involving typing or spelling—have been framed as battles over scientific validity. Critics who defend the position that all communication in AC approaches is not authentic position themselves, at a distance, as defenders of science. Proponents of AC include researchers, as well as clinical professionals and family members who are engaged every day in the lives of nonspeakers. They argue that lived experience and clinical observation are being unjustly dismissed by critics, who exclude two of the three pillars of evidence in evidence-based practice: expertise of clinicians and educators, and client and family perspectives and experience. We support an approach that offers a way to move beyond this impasse by reframing EBP as a dynamic, integrative process rather than a rigid hierarchy that only considers context-stripped research applied outside the experience of the lived experience of human communication. Our understanding of EBP, which reflects its most accurate interpretation provided by professional advocacy, clinical and research organizations, is one that considers multiple sources of evidence and life-span development rather than experimental snapshots that are set up as strawmen in denying the authenticity of nonspeakers.
The Three Pillars of Evidence-Based Practice
A foundational concept underlying this discussion is the widely accepted model of evidence-based practice (EBP) in medical and clinical fields (ASHA, 2005; APA 2005; Prizant, 2011; Sackett et al., 2000). This model describes a three-part integration of:
- Best available research evidence
- Clinical expertise
- Client and family values, preferences and lived experience
We assert that problems arise when one of these components—typically research evidence—is elevated above the others to the point of excluding clinical expertise and lived experience. In fact, in revising their definition in 2006, the APA broadened earlier medical models by explicitly emphasizing: culture, individual differences, patient preferences, and clinical expertise alongside research evidence.
In specific reference to evidence for the effectiveness of AC methodologies, critics have privileged controlled experimental designs while discounting practitioner knowledge and, critically, the perspectives of autistic individuals themselves and those who know them well. We contend that this imbalance has distorted policies by limiting access to newer AC approaches for countless nonspeaking individuals, both children and adults. When interventions are judged solely by whether they meet narrow methodological criteria, approaches that are meaningful and effective for certain individuals—especially those with complex neuromotor or communication profiles—may be dismissed prematurely. For nonspeakers, this is not an abstract concern. It directly affects whether they are offered communication supports, how their communication is interpreted, and whether their expressed thoughts are considered credible.
The Limits of Experimental Research Models
We believe that experimental research designs are not always well-suited to capturing the realities of autism and other complex neurodevelopmental conditions, particularly for individuals with highly individualized profiles. Comparing treatment outcomes under highly controlled circumstances can struggle to accommodate the variability inherent in nonspeakers—especially when differences in their lived experiences, as well as motor differences, sensory sensitivities, and regulatory states play a central role.
It also is well accepted that competence in communication for nonspeakers is often context dependent. Factors such as the presence of a trusted partner, environmental familiarity and predictability, arousal state and overall emotional regulation can significantly influence motivation and engagement in social communication. These variables are difficult to control in experimental settings, yet they are essential to real-world functioning.
As a result, a person exposed to an assessment protocol, such as message passing, the primary method used by critics to determine authenticity of communication, might “fail” under controlled conditions and may not at all reflect a person’s competence in naturalistic contexts. Furthermore, message passing tests remain suspect as they do not meet the basic psychometric requirements of a valid assessment as no validity and reliability data are reported (Kaufer, 2025). And when experimental evidence is upheld as the only valid evidence of communicative competence, entire spheres of human experience are effectively excluded from consideration.
Nonspeakers and the Problem of “Disallowed” Evidence
One of the most striking implications of this discussion is how certain types of evidence are systematically discounted in debates about nonspeakers. Consider firsthand accounts from individuals who communicate via typing or spelling with assistance. Many describe gaining access to language, education, and self-expression after years of being presumed incompetent. These narratives are often detailed, consistent, and deeply reflective as they document the journey of initially learning to communicate with support, progressing to less support over time, and then for some, communicating independently (Jaswal et al., 2026). Such qualitative evidence is routinely accepted as credible within research on human and animal communication, on the natural course of medical conditions, and when exploring different cultural perspectives in anthropology.
Yet, critics frequently reject such qualitative accounts on the grounds that the methodologies of AC always involve influence, and this same assertion is made for any approach of learning to communicate with assistance. In other words, two of the three pillars of EBP are dismissed. From a strictly myopic experimental lens, this approach is considered credible. However, what critics do not ask is the following crucial question: What is the consequence of dismissing lived experience and accounts of numerous credentialed professionals and those who know a person intimately?
If client perspectives are one of the three pillars of evidence-based practice, then excluding them creates a fundamentally incomplete model. It also raises ethical concerns—particularly when the individuals in question have historically been denied opportunities to communicate.
Clinical and Educational Expertise as a Form of Evidence
Another underappreciated component of EBP is clinical expertise. Collectively, professionals draw on decades of work with autistic individuals. Skilled practitioners develop nuanced understandings of the processes of communicating successfully with neurodivergent individuals, both nonspeaking and speaking, that cannot be captured in formal studies, especially when conducted in highly controlled, stress-inducing circumstances by those who do not know a person well.
This includes recognizing subtle indicators of engagement, interpreting idiosyncratic communication attempts, and adapting supports in real time. For nonspeakers, such expertise can be especially critical. A clinician who understands motor planning challenges, for example, may approach supporting communication for a nonspeaking person very differently from one who interprets difficulties from a purely cognitive perspective, that is, a person who does not speak has nothing to say.
This kind of knowledge is often built through relationships and longitudinal observation. It is context-sensitive and requires sensitivity and responsiveness to the individual, hallmarks of successful human communication. While it may lack the apparent objectivity of controlled trials, it is nonetheless a legitimate and indispensable form of evidence.
Critics may view clinical judgment with suspicion, particularly in areas where confirmation bias is a concern. We have seen the impact when researchers come in believing that a person is not communicating authentically, and the approach basically is “Prove me wrong.” This is reflected in the message passing methodology used by critics as the essential test in determining the validity of a nonspeaker’s communication—one either passes or fails, unlike the process of natural communication.
The Role of Skepticism: Necessary but Not Sufficient
To be clear, we do not argue against skeptical inquiry. We acknowledge its importance in maintaining scientific integrity and protecting individuals from ineffective or harmful interventions. That said, we draw a clear distinction between constructive skepticism and dismissive skepticism.
- Constructive skepticism asks questions, seeks clarification, and remains open to new evidence from multiple sources.
- Dismissive skepticism begins with a conclusion—often that a particular approach cannot possibly work—and interprets all data through that lens.
In the context of nonspeakers, dismissive skepticism can have profound consequences. When critics assume that certain communication methods are inherently invalid, they may never consider them to be options, and unfortunately, as has happened, they convince others to dismiss them as well by distorting and weaponizing the application of EBP to confirm long-held biases. This not only limits access but also reinforces the very absence of evidence used to justify the initial skepticism.
We assert that a more productive approach is to investigate under what conditions communication appears to be most reliable, and how those conditions can be understood and replicated. And for those nonspeakers who have become independent, what are the significant ingredients that support this achievement (Jaswal et al., 2026a)? This shifts the focus from debunking to inquiry, from dismissive snapshots to longitudinal observation.
Individualization vs. Standardization
A recurring tension in the conversation is the balance between individualization and standardization. Standardization makes sense from a research perspective but can be problematic in autism, where heterogeneity is the norm. For nonspeakers, individualized approaches are essential. Communication supports may need to be tailored to specific motor profiles, sensory preferences, and regulatory needs. What works for one individual may not work for another—and what works in one context may not be effective in other contexts.
We believe that true evidence-based practice must accommodate this variability. Rather than asking whether an intervention works “in general,” we should ask: For whom does it work, under what conditions, and why (Jaswal et al., 2026a)? This level of specificity is more complex, but it is also more aligned with the realities of clinical practice and lived experience.
Ethical Dimensions: Access, Dignity, and Risk
The issue of EBP as it pertains to nonspeakers also touches on the ethical dimensions of evidence. Decisions about what counts as valid evidence are not neutral; they have real-world consequences for access to services and supports.
For nonspeakers, the risk of false negatives—failing to recognize genuine competence—may be particularly high. If an individual is assumed to lack understanding, they may be denied education, social interaction, and opportunities for self-determination. In documented cases, it has led to abuse, such as in the history of Jordyn Zimmerman as documented in the film, This is Not about Me (Niemeijer, 2021).
Critics often focus on the risk of false positives—attributing competence where it is in question, such as in situations where a person’s communication is influenced by the communication partner. This concern is legitimate, especially considering historical controversies about some false accusations of mistreatment and abuse. However, we suggest that the field must grapple with both types of error, not just one. Unfortunately, nonspeakers also are the most likely individuals to have experienced abuse and trauma (Jaswal et al., 2026b). What if their reports of mistreatment and abuse are dismissed? An ethical approach to evidence-based practice requires balancing these risks, rather than allowing one to dominate the conversation.
Finally, one must consider the ethical violations inherent in conflicts of interest. It is well known that the primary naysayers disseminating their position that assistive communication approaches should be prohibited have been actively engaged for years benefiting from fiscal rewards they earn in expert witness work supporting such prohibitions, with no conflict of interest disclosures in publications and presentations.
Toward a More Inclusive Approach to Evidence
Ultimately, we are calling for methodological innovation that better fits the reality of lived experience and EBP. If existing research paradigms are insufficient to capture the experiences of nonspeakers, then new approaches are needed (Jaswal et al., 2026b).
This might include:
- Participatory research involving autistic individuals as collaborators
- Mixed-methods research that combines quantitative and qualitative data
- Single-case designs tailored to individual profiles
- Ecologically valid assessments conducted in naturalistic settings
In fact, this was a recommendation of the 2023 NIDCD meetings on “Minimally Verbal/Non-Speaking Individuals With Autism: Research Directions for Interventions to Promote Language and Communication.” Such approaches do not abandon rigor; they expand it. They recognize that complexity requires more sophisticated tools and varied tools, rather than oversimplified snapshots and questionable measures such as message-passing tasks.
Implications for Practice and Dialogue
For practitioners, researchers, and families, the conversation offers several actionable takeaways:
- Integrate all three components of EBP, with a bias towards those that include the experiences and perspectives of nonspeakers. Do not privilege experimental, context-stripped approaches at the expense of others
- Approach nonspeaking individuals with a presumption of competence, while remaining attentive to evidence
- Document clinical observations systematically, contributing to a broader evidence base
- Prioritize access to communication, recognizing its foundational role in quality of life
Conclusion: Evidence as a Living Process
We feel it is essential to rethink evidence-based practice not as a fixed hierarchy, but as a living process—one that evolves in response to new data, new perspectives, and new ethical insights.
For nonspeaking autistic and other neurodivergent individuals, this shift could be transformative. It opens the possibility of being recognized as participants in a shared endeavor to understand human communication in all its forms. The goal is not to lower standards, but to broaden them—to create a science that is rigorous enough to be trustworthy, and flexible enough to be humane.
Barry M. Prizant, PhD, CCC-SLP, is an Adjunct Professor in the Department of Communicative Disorders, College of Health Sciences, at the University of Rhode Island. He can be reached by phone at 401-626-0681 or by email at bprizant@gmail.com.
Jessica Teixeira, MS, CCC-SLP, is a Speech-Language Pathologist at Play Haven Pediatric Therapy.
References
American Speech-Language-Hearing Association (2005). Evidence-Based Practice in Communication Disorders
APA Presidential Task Force on Evidence-Based Practice. (2006). Evidence-based practice in psychology. American Psychologist, 61(4), 271–285.
Jaswal, V. K., B. M. Prizant, Barense, M.D., Patten, K., and Stobbe, G. (2026a). “Why We Need to Study Assisted Methods to Teach Typing to Nonspeaking Autistic People.” Autism Research, 1-8.
Jaswal, V. K., B. M. Prizant, Barense, M.D., Patten, K., and Stobbe, G. (2026b). A Reply to letters on “Why We Need to Study Assisted Methods to Teach Typing to Nonspeaking Autistic People” Autism Research, 1-2.
Kaufer, D. (2025). Why message passing is invalid: The test designed to fail autistic people. Kaufer Insights, Substack,substack.com
National Institute on Deafness and Other Communication Disorders (2023). “Minimally Verbal/Non-Speaking Individuals With Autism: Research Directions for Interventions to Promote Language and Communication.”
Niemeijer, M. (Director) (2021). This Is Not About Me [Film]. M&F Films
Prizant, B.M. (2011). The use and misuse of evidence-based practice: Implications for persons with ASD. Autism Spectrum Quarterly, Fall 43-49
Sackett, David L., Sharon E., Straus, W., Scott Richardson, et al. (2000). Evidence-Based Medicine: How to Practice & Teach EBM . 2nd edition. London, England: Churchill Livingstone.
