TIES TIPS Foundations of Inclusion

TIP #6:
Using the Least Dangerous Assumption in Educational Decisions

TIES Center | TIES Inclusive Practice Series (TIPS)


What are high expectations for students with the most significant cognitive disabilities? This question has been raised for decades, with the answers changing over time. Although the conclusion has been that all individuals deserve the chance to show what they know and can do, exactly what that means for students with the most significant cognitive disabilities is just emerging.


Students with disabilities in the United States have a history of exclusion in education. Although it has been more than 40 years since the first laws were enacted to ensure that a child with any disability had access to school, the placement of students with the most significant cognitive disabilities in segregated settings continue (Morningstar, Kurth, & Johnson, 2017). 

Legislation requires access to and assessment of student performance in grade-level academic content (IDEA 1997; ESEA 2001, 2015). Yet, there continues to be a mindset that students with intellectual disabilities should be taught an “alternate” curriculum, one that meets their functional skill needs rather than academics. Spooner and Brown (2011) noted that inclusive efforts for students with moderate and severe intellectual disabilities have focused on the location of their learning, but continued the separate curriculum. The assumption was that this population of students could not learn academic content. Even though this myth has been debunked (Saunders & Wakeman, 2018/2019), it persists. Advocates and researchers continue to encourage practitioners to consider what is relevant for students in this population and plan for what they could do instead of assuming what they cannot do (e.g., Courtade, Spooner, Browder, & Jimenez, 2012; Quenemoen & Thurlow, 2017). 

The least dangerous assumption was first proposed by Donnellan (1984). It is a concept that has guided the approach taken by some, but not all, educators who work with students with the most significant cognitive disabilities. Still, there is evidence that when there is adherence to the least dangerous assumption, students with intellectual disabilities can make progress on the same academic content as their grade-level peers without disabilities (e.g., Heinrich, Collins, Knight, & Spriggs, 2016; Ruppar, Afacan, Yang, & Pickett, 2017).

The least restrictive environment (LRE) requirement in IDEA was designed to ensure that every child be educated with non-disabled peers to the greatest extent possible. Every Individualized Education Program (IEP) team makes decisions about placement based on the student’s strengths and needs, so it is best practice that IEP teams remain up-to-date on current research for educating students in inclusive settings. Research findings indicate that:

  • Inclusive placements in general education classrooms for students with significant cognitive disabilities correlate positively with their achievement (Kleinert et al., 2015).
  • When students with intellectual disabilities are educated with their non-disabled peers they also make progress on social goals (e.g., Brock, Biggs, Carter, Cattey, & Raley, 2016; Henrick, Collins, Knight, & Spriggs, 2016).
  • When students without disabilities are educated in inclusive classrooms, they develop skills like empathy and advocacy, and there is no negative effect on their academic performance (Carter et al., 2016).


The least dangerous assumption is a theory developed in the early 1980s. According to Donnellan (1984), “The criterion of the least dangerous assumption holds that in the absence of conclusive data, educational decisions ought to be based on assumptions that, if incorrect, will have the least dangerous effect on the likelihood that students will be able to function independently as adults” (p. 141). Evidence gathered by Rosenthal and Jacobson (1968) indicated much earlier that teacher expectations could influence student achievement. In the current policy environment when so many expectations are created by test score data or disability label, it is vital that high expectations are set for all students.

Donnellan wrote about the need to practice the least dangerous assumption for students with disabilities. She suggested that if a student does not make progress, we should first assume it is due to a problem with the instruction or materials rather than a student deficit. Jorgensen (2005) outlined five reasons for presuming competence as the least dangerous assumption: (a) human intelligence is multi-faceted, (b) measuring intelligence is flawed, (c) communication and high-quality instruction are needed before we can determine capability, (d) presuming incompetence could be harmful, and (e) even if we are wrong, the consequence is not as harmful as the alternative.

Further information on expectations is provided in the following video clips of a parent and a general education teacher talking about the importance of high expectations from each of their perspectives:

Video 1: Parent: Presuming Competence and High Expectations

Video 2: Gen Ed Teacher: Educational Expectations


The ways in which expectations can play out for an individual student are shown in this case study of Leo. Leo has an intellectual disability and has been in a separate classroom for the past four years. His IEP includes goals for using Augmentative and Alternative Communication (AAC) to make simple requests (e.g., more, drink, bathroom, eat), using behavioral self-management strategies, identifying simple sight words, and sorting objects by color or size. The IEP team is discussing the best placement for Leo. His parents have been pushing to have him included in general education classes. This is the conversation:

Parents: We have been attending trainings on building communication systems and using the least dangerous assumption. It seems that Leo’s behavior outbursts are linked to the fact that he doesn’t have a solid communication system yet. We also are worried because he has been coming home from school with the same types of work for years, and we think he would benefit from joining the regular class where the kids from our neighborhood are.

Principal: What has Leo been working on this past year?

Speech-language pathologist: He’s been working with a new AAC system, but he still hasn’t mastered the basic needs (asking for a drink, identifying his name, etc.). His IEP goals have been pretty similar since Kindergarten.

Teacher: Well, he has been working on many of the same IEP goals for awhile, but that is because he really struggles to remember anything from one day to the next. We do flashcards for sight words and he knows them one day, but then the next week he has forgotten them all. There is no way Leo can do grade-level work. His academics are not even close, and his behaviors would be detrimental to the rest of the students.

After quite a few meetings and discussions and some reading (e.g., Carter, 2018/2019; Jorgensen, 2018/2019), the IEP team realized that Leo seems more interested in his surroundings when he is with same-aged peers, including those without disabilities. His parents share that he finds ways to communicate with his brother’s friends when they come over. Ultimately, on a trial basis, Leo is placed in a general education setting from the time of his arrival at school through lunch. Leo’s parents asked that the educators who work with Leo be given some professional development to support planning for Leo’s transition to the general education classroom. The principal and teachers agreed. During and after the training, everyone worked together to identify potential barriers to Leo’s inclusion and access to the curriculum, and together they problem-solved ways to overcome them. For instance, rather than focusing on Leo having few sight words and a bad memory, the team thought about how to help him access information and show what he knows. Perhaps Leo may not master multiple sight words, but through a free technology, such as Bookshare, he could listen to the same text as his peers, and he could show his understanding using a response board with some choices rather than coming up with each answer on his own.

Leo’s case provides examples of how the least dangerous assumption can be implemented. For each implementation example presented below, there is also the likely negative effect if the least dangerous assumption is ignored. 

Teaching Life, Social, and Academic Skills

In Leo’s inclusive math class, students are working on multi-step mathematical problems. Leo is using his task-analyzed support to complete problems similar to his peers. Leo uses his stamp to write his name, or his AAC to electronically sign, at the top of his math assignment. Like all the students in class, if Leo has a question he is supposed to ask two peers before he asks a teacher. Further, his AAC device is programmed to ask for help and has core words that can be combined to reflect a large number of concepts and ideas. Leo also has some fringe vocabulary for specific units. The math problems are connected to the science lesson being taught later that day.

What might have occurred if the least dangerous assumption had been ignored? Leo works alone at his desk. He circles numbers in isolation on a worksheet. He stamps his name five times in a row on a second worksheet. He staples the worksheets together before he turns them in to his teacher.

Instruction in Natural Contexts and Routines

Leo enters the inclusive classroom and says “hello” to his classroom teacher and friends. What might have occurred if the least dangerous assumption had been ignored? Leo is practicing activating his AAC device to say “hello” in a therapy session in four out of five trials.

More Challenging Content

In his inclusive classroom, Leo uses familiar playing cards to sequence numbers on a number line as part of multi-step math problems that the rest of the class is doing. He sorts information from two different stories to create a Venn Diagram. He uses his name and course subject to identify letter sounds.

What might have occurred if the least dangerous assumption had been ignored? Leo completes three tasks each morning when he arrives at school. These three tasks are his IEP goals related to matching colors and pictures of playing cards, sorting blocks, and circling his name. These tasks are not changed until he demonstrates mastery for five out of five days.

Addressing Barriers to Learning

Leo’s inclusive classroom teacher plans a lesson related to comparing and contrasting states of matter. She plans using tangible objects so that Leo can touch, see, and hear the differences. She provides picture and object response options for concepts for Leo to use on his AAC device. She uses videos for Leo to see the melting and freezing process in a short period of time.

What might have occurred if the least dangerous assumption had been ignored? Leo’s teacher sees Leo as the barrier to learning, and thus uses hand-over-hand support with Leo to sort pictures of hot and cold items because there is only 15 minutes of class time for science.

Focus of Instruction

Leo works on a subset of prioritized vocabulary for each chapter of the text the class is reading. He uses his AAC device for both word recognition and definition. Leo has picture supports that match each vocabulary word and has several opportunities each day to respond to questions using the vocabulary on his communication device. He repeats having the chapter read aloud to him and using his vocabulary as homework.

What might have occurred if the least dangerous assumption had been ignored? Leo’s teacher regularly focuses on a narrow set of skills or topics. Thus, Leo’s vocabulary instruction focuses on flashcard instruction. He works on five words in isolation each benchmark period.


The least dangerous assumption pushes us to consider all students as capable (Jorgensen, 2005). Our challenge is to not think in a deficit mindset but consider what can we do to support students in how they access, engage in, and respond not only to life skills content, but academic content, as well. By including students with the most significant cognitive disabilities in the instruction of all content, students and families are included in a community of learning that sets achievable high expectations.

Learning Activities

Least Dangerous Assumption Learning Activities for Educators: Activity 1

Watch the following video. Be prepared to note where you see evidence of considerations of least dangerous assumption and where there are potential ways to increase considerations of least dangerous assumption.

Where did we see considerations for LDA?

What was happening?

Notes of interest

54 seconds

“Buckle yourself in (the car).”

Rosie is able to complete several life tasks for herself demonstrating her independence to care for herself.


Saying the Pledge of Allegiance.

Rosie is able to recite the Pledge at a young age!


Reading sight words with class “bat.”

Rosie and the rest of her class are choral reading sight words. Rosie is responding at the same time as her classmates, demonstrating her knowledge and not her parroting the responses of others.


Feeding herself outside with class for lunch.


Playing at recess with everyone.


Listening to a story with a large class of students.


Counting coins to a given value.


On the driveway having a conversation with her mom.

Notice that her mom gets down close to Rosie on her level to have a conversation. It was a conversation- not just her mom asking questions of Rosie but Rosie asking questions of her mom, too.


Saying the prayer for dinner.

Rosie is able to pray just like anyone else who chooses to do so.


Feeding herself dinner.


Listening to a story read by her brother.

Rosie is important to her entire family and listens to her brother read her a story at bedtime. Jacob is a reading model for Rosie.


Reading a story to her mom.

Just as her brother read her a story, Rosie is also able to read a story to her mom. Jacob’s model prior is very important. Rosie is not only able but expected to read the story.


Singing a song with her class.

Where did we see places to potentially improve considerations for LDA?

What was happening?

Notes of interest

49 seconds

Dad feeding Rosie at the table.

While we don’t see what is in the spoon (it could have been medicine which may be why her Dad fed it to her), Rosie is able to feed herself and should do so.

53 seconds

“Your backpack is already in the car.”

Rosie is young. Parents of many young children help in morning routines, but it wouldn’t take much to have Rosie carrying her backpack to the car as she is able.


Playing checkers with the teacher.

Again, we only see a second of this interaction so we can’t be sure that Rosie wasn’t given the chance to decide her own move. The clip includes the teacher pointing to correct move so we would want to ensure Rosie had a chance to make her own move before assistance is given.


Dad brings the bookbag to Rosie at the end of the school day.

It is not clear if this is a regular practice (like the backpack in the car), but it would be easy to allow Rosie to get her own bookbag before leaving school as all children do.

Least Dangerous Assumption Learning Activities for Educators: Activity 2

The least dangerous assumption basically states that if we aren’t 100% sure, we should make decisions that, if wrong, have the fewest negative repercussions against the person. At different times of a person’s life, these decisions may include what someone should or shouldn’t learn, where someone should learn, where someone should live, with whom someone should live, etc.

The least dangerous assumption is important because we know:

  • Having high expectations makes a difference
  • IQ is not destiny
  • Not talking is not the same as not having something to say
He can't because... : Behavior, A disability label, a test score (IQ), missing skill or info. How is each assumption going to limit the person's opportunities?

So, how do you create least dangerous assumption opportunities in your IEP meetings, your schools, and your life?  Let’s look at some possible scenarios.

“Shaquan has Down syndrome so I think this classroom may be best. He will learn the functional skills he’ll need to get a job.”

The assumptions being made:

  • All people with Down syndrome have the same needs.
  • Functional skills are often defined as “daily living skills” and typically include hygiene skills, making change, and following basic directions. “Academic” skills such as reading, writing, science, and math are not considered as a priority or achievable for some students.

What is a response that reflects a least dangerous assumption? Write one before moving on to see some possible responses.

“Down syndrome is only one part of who Shaquan is.”

“Functional skills for Shaquan are reading, making friends, and learning how to advocate for himself.”

“How can we support Shaquan learning all the skills he needs to help him get access to general education classroom and content?”

Kaitlyn needs to learn to better use her AAC system before she will benefit from a general education classroom.

What assumptions are being made?

  • Communication is taught in isolation.
  • Not talking is the same as not having anything to say.

What is a response that reflects the least dangerous assumption? Write one response before moving on to see some possible responses.

“Let’s give Kaitlyn more opportunities to practice communication and more people to communicate with.”

“Rather than waiting for Kaitlyn to ‘prove herself’ by communicating, let’s begin by giving her things to communicate about.”

“Since Kaitlyn doesn’t yet have a strong communication system, we can’t be sure what she does and doesn’t understand. We must then give her access to as much as we can, in case her receptive language is stronger than her expressive currently is.”

Daniel’s behavior is not appropriate for a general education classroom.  Once he learns better ways to handle his frustration then we can talk about moving him.

What assumptions are being made?

  • Behavior is a prerequisite for being allowed in a classroom.
  • Behavior is not communication. 

What is a response that reflects the least dangerous assumption? Write one response before moving on to see some possible responses.

“What is Daniel’s behavior telling us? Is he engaged in the classroom environment?”

“How can we support Daniel to learn better ways to handle his frustration?”

“What strategies and supports can we put in place in a general education classroom to help Daniel?”

What assumptions are being made?

Shandra’s IQ is 60. She won’t be safe in a general education setting.
  • IQ is destiny.
  • Shandra will only be safe if adults take care of her and adults will always be around to take care of her.
  • Shandra’s peers will be mean to her.

What is a response that reflects the least dangerous assumption? Write one response before moving on to see some possible responses.

“What are supports that Shandra needs to access reading, writing, math, science, etc.?”

“How can we set up peer networks or a circle of friends for Shandra?”

“What strategies can we use to help Shandra build her advocacy skills?”


  • Johnson, D. R. (2015). The power of high expectations for special education students. CEHD Vision 2020 Blog. Retrieved from

  • McGrew, K. S., & Evans, J. (2003). Expectations for students with cognitive disabilities: Is the cup half empty or half full? Can the cup flow over? Retrieved from University of Minnesota, National Center on Educational Outcomes website:

  • Quenemoen, R. F., & Thurlow, M. L. (2017). Standards-based reform and students with disabilities. In J. F. Kaufman & D. P. Hallahan (Eds.), Handbook of Special Education (pp. 203–217). New York: Routledge.

  • Quenemoen, R. F., & Thurlow, M. L. (2019). Students with disabilities in educational policy, practice, and professional judgment: What should we expect? Minneapolis, MN: University of Minnesota, National Center on Educational Outcomes.


  • Brock, M. E., Biggs, E., Carter, E. W., Cattey, G., & Raley, K. (2016). Implementation and generalization of peer support arrangements for students with significant disabilities in inclusive classrooms. The Journal of Special Education, 49, 221–232.
  • Carter, E. W. (2019). Inclusion, friendships, and the power of peers. Impact: Feature Issue on Inclusive Education for K-8 Students with the Most Significant Cognitive Disabilities, 31(2). Retrieved from
  • Carter, E. W., Asmus, J., Moss, C. K., Biggs, E. E., Bolt, D. M., Born, T. L., & Fesperman, E. (2016). Randomized evaluation of peer support arrangements to support the inclusion of high school students with severe disabilities. Exceptional Children, 82(2), 209–233.
  • Courtade, G., Spooner, F., Browder, D., & Jimenez, B. (2012). Seven reasons to promote standards-based instruction for students with severe disabilities: A reply to Ayres, Lowrey, Douglas, & Sievers (2011). Education and Training in Autism and Developmental Disabilities, 47(1), 3–13. Retrieved from
  • Donnellan, A. M. (1984). The criterion of the least dangerous assumption. Behavioral Disorders, 9(2), 141–150.
  • Heinrich, S., Collins, B., Knight, V., & Spriggs, A. (2016). Embedded simultaneous prompting procedure to teach STEM content to high school students with moderate disabilities in the inclusive setting. Education and Training in Autism and Developmental Disabilities, 51, 41–54.
  • Jorgensen, C. (2005). Least dangerous assumption: A challenge to create a new paradigm. Disability Solutions, 6(3), 1, 5–9. Retrieved from
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  • Kleinert, H., Towles-Reeves, E., Quenemoen, R., Thurlow, M., Flueege, L., Weseman, L., & Kerbel, A. (n.d.). Kleinert, H., Towles-Reeves, E., Quenemoen, R., Thurlow, M., Flueege, L., Weseman, L., & Kerbel, A. (2015). Where students with the most significant cognitive disabilities are taught: Implications for general curriculum access. Exceptional Children, 81(3), 312–328.
  • Morningstar, M. E., Kurth, J. A., & Johnson, P. E. (2017). Examining national trends in educational placements for students with significant disabilities. Remedial and Special Education, 38, 3–12.
  • Rosenthal, R., & Jacobson, L. (1968). Pygmalion in the classroom: Teacher expectation and pupils’ intellectual development. New York: Rinehart and Winston.
  • Ruppar, A. L., Afacan, K., Yang, Y., & Pickett, K. J. (2017). Embedded shared reading to increase literacy in an inclusive English/language arts class: Preliminary efficacy and ecological validity. Education and Training in Autism and Developmental Disability, 52, 51–63.
  • Saunders, A., & Wakeman, S. (2019). Myth vs. fact: What is true about including students with the most significant cognitive disabilities? Impact: Feature Issue on Inclusive Education for K-8 Students with the Most Significant Cognitive Disabilities, 31(2). Retrieved from
  • Spooner, F., & Brown, F. (2011). Educating students with significant cognitive disabilities: Historical overviews and future progressions. In J. M. Kaughmann & D. M. Hallahan (Eds.), Handbook of special education (pp. 503–515). New York: Routledge.

TIPS Series: Tip #6, July 2019

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  • Taub, D., Wakeman, S., Saunders, A., Thurlow, M. L., & Lazarus, S. S. (2019). Using the least dangerous assumption in educational decisions (TIPS Series: Tip #6). Minneapolis, MN: University of Minnesota, TIES Center.

TIES Center is supported through a Cooperative Agreement (#H326Y170004) with the Research to Practice Division, Office of Special Education Programs, U.S. Department of Education. The Center is affiliated with the National Center on Educational Outcomes (NCEO) at the Institute on Community Integration (ICI), College of Education and Human Development, University of Minnesota. The contents of this report were developed under the Cooperative Agreement from the U.S. Department of Education, but do not necessarily represent the policy or opinions of the U.S. Department of Education or Offices within it. Readers should not assume endorsement by the federal government. Project Officer: Susan Weigert

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