How are baseline communication skills determined by speech and language therapy for autism? 

Speech and language therapists play an essential role in establishing a clear, meaningful baseline for autistic children, young people and adults. UK practice, informed by NICE, the RCSLT, the NHS and the National Autistic Society, emphasises that a baseline must reflect real-life communication, autistic strengths, sensory needs and preferred communication styles. 

Rather than relying on one test, SLTs build a holistic profile that shows how the person communicates now, how communication feels for them, and what supports they already use. This baseline becomes the foundation for co-produced goals and later progress measurement. 

Understanding what a baseline is 

A baseline describes the individual’s current communication across everyday contexts. According to the RCSLT, SLTs assess how someone understands and uses language, how they interact socially, how they express needs and ideas, and how sensory or emotional needs influence communication. 

For children, NICE CG170 requires a comprehensive multidisciplinary assessment that gathers developmental history, educational information and direct observation of communication. 

For adults, NICE CG142 stresses understanding how communication functions across home, relationships, education and work, including sensory sensitivities and mental health. 

Baselines therefore describe not just skills, but the conditions under which communication succeeds or breaks down. 

What SLTs include in a baseline 

Speech and language therapists combine several complementary approaches to ensure the baseline is accurate, person-centred and meaningful. 

1. Developmental and communication history 

SLTs gather information from autistic people, families and professionals to understand: 

• preferred communication modes (speech, AAC, gestures, writing) 

• sensory factors that support or hinder understanding 

• experiences of overload, shutdown or anxiety related to communication 

• strengths, interests and motivations 

This aligns with the NAS emphasis on two-way communication and the need for others to adapt their communication too. 

2. Naturalistic observation 

UK NHS autism teams, such as Newcastle Hospitals, observe autistic people in play, daily routines, school activities and unstructured social settings. Observations include: 

• joint attention and engagement 

• turn-taking and conversational reciprocity 

• gesture and non-verbal communication 

• symbolic play 

• emotional regulation 

• initiation versus response patterns 

This offers ecologically valid information that standardised tests cannot always capture. 

3. Standardised receptive and expressive language measures 

Where appropriate, SLTs may use vocabulary tests, comprehension tasks or expressive-language tools. Evidence from multiple studies (for example, receptive vocabulary research summarised in PMC3797266 and PMC4205715) shows that autistic people often present with uneven receptive–expressive profiles, making detailed assessment important. 

However, SLTs interpret scores cautiously, knowing that sensory overload, anxiety or unfamiliar settings can suppress performance. 

4. Pragmatic and interaction-based assessment 

Pragmatic tools such as the CCC-2 help identify challenges with: 

• inferencing 

• conversational turn-taking 

• interpretation of figurative or ambiguous language 

• reading others’ intentions 

Evidence highlights the diagnostic and functional value of these measures (PMC9075340; PMC9944009). 

5. Baseline measures for minimally verbal individuals 

Research on minimally verbal autistic children stresses the need to profile: 

• intentional communication 

• communicative acts (requests, comments, protests) 

• joint attention 

• imitation 

• symbolic play 

• receptive understanding 

The landmark review Assessing the minimally verbal child highlights the importance of extended observation and multiple methods, especially when formal testing is difficult. 

6. AAC-related baseline assessment 

When AAC is relevant, SLTs evaluate: 

• understanding of symbols, pictures, signs or written words 

• ability to navigate visual supports 

• motor, sensory and cognitive access factors 

• communicative intent and reliability 

The RCSLT AAC guidance frames AAC baselines as functional and autonomy-focused. Tools such as the Communication Matrix (validated in PMC5968331) map early and pre-symbolic communication clearly. 

Evidence underpinning baseline variables 

A strong evidence base supports the SLT focus on interaction, play, receptive language and engagement: 

• Baseline joint attention and play predict later language outcomes (JASPER RCT: PubMed 22965298). 

• Baseline receptive language predicts spoken-language gains in early intervention (PMC10460274). 

• Multimodal baselines (speech, gesture, behaviour, AAC) are essential for minimally verbal children (PMC6516977). 

• Social-communication baselines guide targeted intervention in naturalistic programmes (JASP+EMT+SGD trial). 

• For adults, communication baselines must consider sensory overload, workplace communication and accessibility (PMC12271282). 

How SLTs use the baseline to support intervention 

Baselines inform: 

• co-produced communication goals 

• decisions about AAC 

• environmental and sensory adjustments 

• Education, Health and Care Plans (EHCPs) 

• outcome measurement frameworks 

This reflects the RCSLT outcomes guidance and the Five Good Communication Standards, which emphasise person-centred, functional, measurable outcomes. 

Challenges and considerations 

Despite strong practice guidance, several challenges remain: 

• Standardised tests may not reflect communication in noisy, unpredictable or demanding environments. 

• Minimally verbal individuals may require extended observation and adapted tools. 

• Adult baselines are under-researched in UK contexts. 

• Autistic-defined outcomes such as reduced communication anxiety or improved autonomy are rarely reflected in traditional measures. 

The RCSLT encourages SLTs to avoid goals that promote masking and instead document communication strengths, preferences and needs as the basis for respectful, meaningful intervention. 

Takeaway 

Speech and language therapists determine baseline communication in autism through a holistic, multi-method approach informed by NICE, the RCSLT, the NHS and the NAS. A baseline is not simply a test score; it is a detailed portrait of how an autistic person communicates in real life, what supports they need and what matters to them. This forms the foundation for effective, ethical and person-centred intervention. 

If you or someone you support would benefit from early identification or structured autism guidance, visit Autism Detect, a UK-based platform offering professional assessment tools and evidence-informed support for autistic individuals and families.