MIGDAS-2 vs ADOS-2: What Each Autism Assessment Actually Lets You See

The MIGDAS-2 and the ADOS-2 are not two versions of the same assessment. They ask different questions under different conditions, and what you learn from each one is different as a result. This article explains what each is, how they differ, and why neither of them produces a diagnosis on its own.

What is the ADOS-2?

ADOS-2 stands for the Autism Diagnostic Observation Schedule, second edition. It uses a standardised series of activities and social situations to create opportunities for autism-related patterns of communication, interaction, play, and behaviour to be observed and coded. It includes different modules, selected according to the person's age, developmental level, and expressive language.

What is the MIGDAS-2?

MIGDAS-2 stands for the Monteiro Interview Guidelines for Diagnosing the Autism Spectrum, second edition. It was developed by Marilyn Monteiro and Sheri Stegall and published in 2018. It can be used across the lifespan, and includes parent or caregiver and teacher questionnaires as well as different interview protocols for people with limited or no verbal fluency, verbally fluent children and adolescents, and verbally fluent adults.

The interaction is shaped around the person's sensory preferences, interests, and communication style, creating opportunities for them to show how they experience, understand, and organise their world. The direct interview is organised around three broad areas:

• sensory use and interests
• language and communication
• social relationships and emotional responses

Rather than producing a total score or a cut-off, the process supports the clinician to develop a narrative Pattern of Observations. Observations may be described as consistent with autism, not consistent with autism, or unclear, with the reasoning made explicit.

That last option matters. Uncertainty is not a failure of assessment. Sometimes the available information does not yet support a confident conclusion, or different explanations remain possible. A careful clinician should be able to say that clearly rather than forcing a child's complex presentation into a conclusion the evidence cannot yet support.

This is one of the features I value most about the MIGDAS-2. It asks the clinician to describe what they observed, explain how they understood it, and take responsibility for the reasoning that connects the evidence to the conclusion. It also leaves room for a genuinely uncertain finding. More of our instruments should.

How they differ

These are different methodological approaches. One standardises the conditions so that particular patterns of behaviour can be observed and coded within a consistent framework. The other individualises the conditions so that the person's distinctive patterns can be explored and understood in context.

Put simply, the ADOS-2 asks "how do this child's behaviours compare on a standardised measure?", while the MIGDAS-2 asks "what is this child's way of experiencing and communicating, described in their own terms?"

Both approaches produce information. Neither replaces clinical judgement. The diagnosis rests on what the clinician does with all the available evidence, including where different sources agree, where they differ, and what those differences may mean.

What happens in the room with your child

I am listening for patterns, exploring examples in more depth, and trying to understand what a particular behaviour may be communicating or helping this child manage. At the same time, I keep other possible explanations in view, even when I do not name each one aloud. All of this contributes to the formulation: an account of how the child's experiences, strengths, differences, and areas of difficulty fit together, and what may help them feel understood, supported, and able to participate.

Much of what I learn comes from contrast, rather than from any single observation.

I notice what happens to a child's language when we move from a preferred topic to one I have chosen. I look at how connection and reciprocity change when they feel regulated, and what becomes harder when they are overwhelmed or working hard to cope. I consider what happens when movement is welcomed, compared with when stillness is expected. I compare a structured task with a more open-ended social moment. I pay attention to the differences between what school observes during the day and what family sees when the child returns home at five o'clock.

Most importantly, I consider not only what a child can do, but what it takes for them to do it.

When a child is highly verbal, fluent speech does not answer the broader question. I want to understand whether communication becomes easier or more effortful when the conversation moves away from their interests. I notice whether we are building a conversation together or whether I have gradually become an audience. I observe what happens when I interrupt, change direction, or introduce something unexpected. I consider whether social information is recognised spontaneously or becomes clearer once I provide a prompt. I also ask what a strong interest offers the child. It may bring pleasure, support connection, create predictability, or provide scaffolding for communication, and it may do several of these things at once.

Fluent conversation and comfortable eye contact describe what I observed in that particular interaction. On their own, they do not tell me how communication feels for the child, how much conscious effort it requires, or whether the same capacities remain available across different people, settings, and demands.

None of this can be understood without a careful developmental history. The MIGDAS-2 includes structured guidance for gathering information from parents or caregivers and teachers, alongside direct interaction with the child or young person. When I take that history with a family, I am looking for specific examples rather than broad conclusions.

"She is fine socially" tells me very little on its own. I need to understand what friendship looks like for her. Who usually initiates contact? What happens when another child changes the rules halfway through a game? How does she recognise that someone may be frustrated or confused, and what does she do next? How much preparation or rehearsal happens before a party? What does she need during the event, and what do the following two hours look like?

These details help us understand not simply whether a child appears capable, but how they experience social situations, what they may be doing to navigate them, and what conditions allow connection to feel more natural and sustainable.

What it is like to be the child in the assessment

There is a second reason I work this way, and it is not evidential. It is what the assessment is like from the other side of the room.

Picture being eight. You are taken to an unfamiliar room to meet an unfamiliar adult. You know they are working something out about you, though not exactly what. The adult brings out activities you did not choose and asks questions whose purpose is not obvious. They watch how you talk, move, play, and respond. Underneath all of it is a question about what is different about you, and nobody has said it out loud.

For a child who has spent years working hard to get things right, that is not a neutral experience. It is one more room to read, one more adult to satisfy, one more situation to get through without anyone noticing how much it took. And then what we are assessing is how well a child copes with being assessed.

Lower demand gives you more material, not more certainty

There is an assumption in the field that making an assessment less demanding makes it less rigorous. My experience runs the other way. Taking out the demands that are not doing any diagnostic work usually gives me more to look at: more spontaneous language, more humour, more visible regulation, a sharper difference between what happens when the child's brain is interested and when it is not, and more of what they can tell me about their own inner world.

A child who finds direct questions very hard can communicate a great deal on paper. I don't know is often not the absence of an answer. It is an answer that is not available in speech, under time pressure, to someone they met forty minutes ago, and it can arrive intact when the child is allowed to draw it instead. A child who looks quiet and socially uncertain can become precise and expansive the moment you go somewhere they know well. A child who presents as entirely settled can show you, given time and a low-pressure route to it, how much that presentation has been costing.

None of that is noise around the assessment. It is the information I came for.

More material is not more certainty. A richer sample gives me more latitude in how I read it, and latitude is exactly where a clinician's expectations do their damage. The two claims hold together as long as you keep them apart. The conditions determine how much you get to see. The history, what school and home can tell us, and the alternative explanations determine what you are entitled to conclude from it.

The child should not have to earn being understood

Many neurodivergent children arrive at an assessment having already received years of commentary about themselves. Too sensitive. Too much. Not trying. Overreacting. Too rigid. Needs to be more flexible. Needs to cope. Plenty of them have no idea why things that look manageable for everyone else are so much harder, and a lot of them have become very good at making sure nobody finds out.

So I would rather the assessment not become one more adult cataloguing the ways a child is different. What I am after is the child meeting an adult who gets interested in the logic of their brain. There is a reason predictability matters that much. There is a reason a day at school can look fine from the outside and cost everything on the inside. There is a reason an interest can feel less like a hobby and more like the one place a brain gets to rest. My job is not to tell a child those things are wrong. It is to work out how they fit together, and to say so.

What the research does and does not say

A 2023 meta-synthesis of studies with autistic people in the UK, most of them diagnosed in adulthood, described the diagnostic process as typically deficit-focused and distressing, and found that diagnosis often opened up self-understanding and self-kindness where there had previously been self-criticism. The authors recommend that clinicians recognise strengths and support the person during the assessment itself, not only at feedback. A 2025 study of twelve young people aged eighteen to twenty-six going through mental health assessment found the same things mattered: being treated as a person rather than a set of conditions, having some say, and not having their account dismissed.

Neither study is about the MIGDAS-2, neither is about children, and one of them is twelve people. What they support is the narrow claim that how an assessment is conducted affects what someone takes away from it. I think that carries to children, but I am extrapolating, and I would rather say so than dress it up as more.

It changes what I count as having done the job

The clinical conclusion still has to be sound. History, the alternative explanations, information from school and home, functional impact, and an honest answer to whether something else fits better.

But I have got a second measure alongside it. Did the child spend ninety minutes working out whether they were answering correctly, or did they find out that this was a room where they did not have to perform being okay? Did I finish the assessment knowing more about the child while the child left knowing nothing more about themselves?

Psychological assessment is one of the few settings where we are handed permission to look very closely at another person. If we are going to ask a child to let us in, they should be able to walk out feeling more understood than inspected.

Why we do not rely on any single instrument

The ADOS-2 has far more research behind it than the MIGDAS-2, and I would rather be plain about that than have you find out elsewhere.

Standardisation does a job. A fixed administration constrains what I can attribute to the child and what I have to attribute to myself, because the conditions were not mine to choose. It makes my observations comparable to those of a clinician in another town who has never met this family, and it makes it harder to find what I already expected to find. Any clinician who has formed an impression in the first ten minutes and spent the next fifty collecting support for it understands why that constraint exists.

A 2025 meta-analysis of diagnostic tools in children and adolescents rated the certainty of evidence for the ADOS-2 as moderate, the highest rating of anything it reviewed. In plain terms, across the pooled studies it identified about nine in ten autistic children, and roughly three in ten children who were not autistic still met its threshold. A 2026 analysis of studies done in real clinics rather than research samples found the same shape, with the false positives concentrated among verbally fluent adolescents and adults who also had other mental health difficulties.

That second analysis also shows how much the picture varies by module. Specificity was highest for the youngest children and fell steadily through the modules used with older, verbally fluent people. For a young child, the chance of a false positive is considerably lower than the pooled figure suggests.

That finding matters more than it sounds. In that group the problem is not mainly that the ADOS-2 misses autistic people. It is that autism can look like other things, other things can look like autism, and telling them apart is a job no instrument does on its own. A warmer, more adapted assessment does not solve that. If anything, it gives the clinician more room to read what she expects. What solves it is the developmental history, what school and the other adults in your child's life can tell us, the alternative explanations followed properly rather than noted and left, and a willingness to write unclear when unclear is what the evidence says.

The authors of that 2025 review put it plainly: diagnostic tools should be regarded as adjunctive aids rather than comprehensive substitutes for diagnosis.

One caveat runs the other way. These figures are measured against clinicians' own judgement, so a child missed by both the instrument and the clinician is not in them at all. The research cannot tell us about the children nobody is finding.

The MIGDAS-2 has much less published research. Its author has said so. In a 2021 webinar Q&A she confirmed that studies comparing it with the ADOS-2 have not been done, and her own guidance is that anyone using the MIGDAS-2 should also use standardised autism-specific rating scales, naming the SRS-2 or the ASRS along with the CARS2. We do, as well as others. I have looked for anything published since that changes the research position. There is not anything.

That pairing is better founded than it might look. In the same 2025 review, the CARS had the highest specificity of any instrument assessed, well above the ADOS-2's. Running a qualitative process alongside a highly specific rating scale is not a compromise between rigour and warmth. It is a reasonable way to get both.

So there are claims you will not read on this page. That the MIGDAS-2 is more accurate than the ADOS-2. That it picks up girls the ADOS-2 misses. That it captures masking and the ADOS-2 does not. Those claims are easy to find. They are not supported, and I would rather you trusted us because we do not make them.

I use the MIGDAS-2 because it fits how I work. That is exactly why I keep checking it.

What we bring to the assessment

An instrument gives you an hour or two with a child under particular conditions. What we bring to that hour is a way of understanding children that the instruments do not contain.

Masking: the effort a child spends appearing to cope, and what it costs them by half past three. The double empathy problem: the argument that misunderstanding between autistic and non-autistic people runs in both directions, which changes what a social difficulty means.

Neither of these is part of the MIGDAS-2. They are part of how we understand children, and they shape what we ask, what we notice, and what ends up in the report.

What an assessment here includes

An assessment at Hunter Children's Clinics draws on all of the following, and no single part of it produces the diagnosis:

• a detailed developmental history with you, taken as examples rather than yes-or-no answers
• what your child's school and the other adults in their life can tell us
• standardised rating scales completed by parents and teachers
• direct assessment sessions with your child, built around the MIGDAS-2 where possible, with the ADOS-2 and ADI-R where clinically indicated
• a formulation that considers the alternatives before it settles, including anxiety, ADHD, language, learning differences, trauma, temperament, and what the environment is asking of your child
• a written report, and a conversation about what it means and what happens next

You can read more about our autism assessment service, our psychology assessment process, and our psychology and therapy service, and see current fees on our fees and referrals page.

What neuro-affirming means here

A neuro-affirming assessment is shaped by more than the physical environment. It requires the child's own account of their inner experience to be recognised as meaningful evidence and represented alongside clinical observations and information from others. It also requires genuine consideration of alternative explanations, including those that may not align with the expectations brought into the assessment.

This does not mean removing all challenge. Adaptations to the assessment conditions are methodological decisions, because they affect what can be observed and how confidently findings can be interpreted. A child who becomes overwhelmed or shuts down under standardised demands may provide limited information about their underlying abilities. A child who feels entirely comfortable may not encounter the situations in which their differences or support needs typically become apparent. Both responses are informative. The interaction between the child, the environment, and the assessment demands forms part of the clinical data, whichever instrument is used.

What makes an assessment good

Not which observation instrument was used.

The assessments that go wrong tend to go wrong earlier than the observation. A history taken as a checklist. An alternative explanation written down and left there. Home and school disagreeing, and the clinician siding with whichever one they had seen. A formulation nobody argued against before it was signed.

Those are the places the quality gets decided, whichever instrument is in the room. Australia's national guideline asks for the same thing: a comprehensive evaluation drawing on multiple sources of information and clinical judgement, with no instrument standing in for the conclusion. And the report has to be usable by the people who will be with your child for the next six years, or the rest is paperwork.

What this means for you

The practical message is a reassuring one. You do not need to choose the instrument yourself, and you do not need to worry that one label on a form determines the outcome. The clinician makes that decision based on your child, and they can explain their reasoning to you. If you have questions about which approach will be used, it is completely reasonable to ask at the initial consultation. Understanding the process can help both you and your child feel more comfortable going in.

A diagnosis can change how a child understands themselves, how others understand them, and what support their family can request at school and elsewhere. I take that responsibility seriously.

My role is to reach a clear, well-supported conclusion by bringing together the child's developmental history, their experiences and strengths, information from the people who know them, their presentation across settings, and what I observe during the assessment. No single instrument determines that conclusion. The report should show how the evidence fits together, which other explanations were considered, and why the final formulation makes sense.

The MIGDAS-2 gives me a different way of meeting a child. I can follow their interests, place something in their hands, welcome movement, and reduce the pressure to interact in a particular way. Then I can become curious about what changes. I can notice when language becomes more effortful. I can explore whether an interest brings joy, supports regulation, creates connection, or helps hold the day together. I can ask a child what it is like to be them, and give their answer room to emerge, because the interaction feels less like a test and more like a genuine attempt to understand.

Standardisation gives me something equally important. It provides structure, consistency, and a check on my own impressions. I need that too.

If I have done the assessment properly, your child leaves with more than a diagnostic conclusion. They leave with an explanation of how they communicate, regulate, connect, learn, and experience the world. An explanation that recognises their strengths, makes sense of what is difficult, and identifies the conditions in which they are most able to participate and thrive.

It should be an explanation that stands up when carefully questioned, and gives the adults around your child something specific and useful to do on Monday.

Frequently asked questions

What is the MIGDAS-2?
The MIGDAS-2, the Monteiro Interview Guidelines for Diagnosing the Autism Spectrum, second edition, is a qualitative, sensory-based interview and observation. The interaction is shaped around the person's sensory preferences, interests, and communication style, and is organised around sensory use and interests, language and communication, and social relationships and emotional responses. Rather than a total score or a cut-off, it produces a narrative Pattern of Observations.

What is the ADOS-2?
The ADOS-2, the Autism Diagnostic Observation Schedule, second edition, is a standardised observation. It uses a set series of activities and social situations to create opportunities for patterns of communication, interaction, play, and behaviour to be observed and coded. Different modules are selected according to the person's age, developmental level, and expressive language.

What is the difference between the MIGDAS-2 and the ADOS-2?
They are different methods. The ADOS-2 standardises the conditions so that behaviour can be observed and coded within a consistent framework, producing scores that compare across children. The MIGDAS-2 individualises the conditions so that a person's own patterns can be explored and understood in context, producing a written profile. Neither replaces clinical judgement.

Is the MIGDAS-2 more accurate than the ADOS-2?
That claim is not supported. The author of the MIGDAS-2 has confirmed that studies comparing it with the ADOS-2 have not been done. Claims that the MIGDAS-2 is more accurate, picks up girls the ADOS-2 misses, or captures masking when the ADOS-2 does not are easy to find, but they are not supported by research.

How accurate is the ADOS-2?
A 2025 meta-analysis of diagnostic tools in children and adolescents rated the certainty of evidence for the ADOS-2 as moderate, the highest rating of any tool it reviewed. Across the pooled studies it identified about nine in ten autistic children, and roughly three in ten children who were not autistic still met its threshold. A 2026 analysis found that false positives were more common with the modules used for older, verbally fluent people, and lower for young children.

Can the MIGDAS-2 diagnose autism on its own?
No. Neither the MIGDAS-2 nor the ADOS-2 produces a diagnosis on its own. A diagnosis rests on what the clinician does with all the available evidence, including the developmental history, information from home and school, standardised rating scales, direct assessment, and a careful look at other possible explanations.

What does it mean if an assessment result is "unclear"?
With the MIGDAS-2, observations may be described as consistent with autism, not consistent with autism, or unclear, with the reasoning made explicit. An unclear result is not a failure of assessment. It means the available information does not yet support a confident conclusion, or different explanations remain possible, and a careful clinician should say so rather than force a conclusion the evidence cannot yet support.

Which autism assessment does Hunter Children's Clinics use?
Our psychology team uses the MIGDAS-2 where possible, with the ADOS-2 and the Autism Diagnostic Interview, Revised (ADI-R) where clinically indicated. Standardised autism-specific rating scales, including the SRS-2, the ASRS, and the CARS2, are used alongside it, as part of an assessment that also draws on developmental history and information from home and school.

This article is general information only and is not a substitute for individual medical advice. If you have concerns about your child, please speak with your GP, paediatrician, or treating clinician.

Sources

• Monteiro, M. J., & Stegall, S. (2018). MIGDAS-2: Monteiro Interview Guidelines for Diagnosing the Autism Spectrum, Second Edition. Western Psychological Services.
• Monteiro, M. J. (2021, 22 July). Autism Conversations: Individualizing Educational Interventions with the MIGDAS-2 Evaluation Process. Webinar Q&A, Western Psychological Services.
• Fulceri, F., Caruso, A., Micai, M., Gila, L., Tancredi, R., Fatta, L. M., et al. (2025). Autism diagnosis in children and adolescents: A systematic review and meta-analysis of test accuracy. Neuroscience & Biobehavioral Reviews, 173, 106164. https://doi.org/10.1016/j.neubiorev.2025.106164
• Module-specific diagnostic accuracy of ADOS-2 in real-world clinical referral populations: An updated systematic review and HSROC meta-analysis. (2026). Frontiers in Psychiatry. https://doi.org/10.3389/fpsyt.2026.1840734
• Wilson, R. B., Thompson, A. R., Rowse, G., & Freeth, M. (2023). The experience of seeking, receiving, and reflecting upon a diagnosis of autism in the UK: A meta-synthesis of qualitative studies conducted with autistic individuals. Research in Autism Spectrum Disorders, 103, 102135. https://doi.org/10.1016/j.rasd.2023.102135
• Dorata, A., Andersen, H., Bisp, S., & Appleton, R. (2025). "I wish they heard my story rather than my conditions." A qualitative exploration of young people's experiences during mental health assessment in the UK. PLOS Mental Health, 2(9), e0000436. https://doi.org/10.1371/journal.pmen.0000436
• Milton, D. E. M. (2012). On the ontological status of autism: the 'double empathy problem'. Disability & Society, 27(6). https://doi.org/10.1080/09687599.2012.710008 (open copy: https://kar.kent.ac.uk/62639/)
• Autism CRC. National Guideline for the Assessment and Diagnosis of Autism in Australia (2023 update), approved by the NHMRC.