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The Complexity Approach for Speech Therapy: How to Get Started

Updated: May 8

The complexity approach is an evidence-based speech therapy treatment for young kids with phonological disorders

Depending on how long you've been in this field, you may have already discovered that the learning never ends. Just when you think you've gotten a handle on things, new philosophies, insights, or research emerge, sending you back to the drawing board.

When I was in graduate school, the treatment approaches I learned about for speech sound disorders consisted of the Cycles Approach and the traditional, Van Riper approach. That's pretty much it!

But since then, new ideas have come along. And when there's evidence to back them, it's time to add new tricks to my tool kit. I've had to do this with contrastive intervention approaches and am very glad I did. You can check out my post on them here; it has helpful information and resources for you to use to implement them.

Here's a cool thing you may not be aware of: ASHA has a page of "evidence maps" here; they aggregate the latest evidence on a variety of topics that you can search. If you look up the complexity approach, you'll see that there is a ton of research supporting the effectiveness of this approach. In a continuing ed course I took about the complexity approach by Holly Storkel, she called it "the most evidence-based tool you're not using."

What is the complexity approach for speech therapy?

The complexity approach for speech therapy is a treatment model for children ages 3-6 with very low scores on articulation tests due to their not being able to correctly articulate at least 5-7 speech sounds. The key idea in this approach is that you choose 1 or 2 treatment targets that are "complex" (complexity is determined based on a variety of different factors that are explained below), which will result in "system-wide change," caused by the child's broadened understanding of the phonological system, as well as their increased ability to produce the sounds of their language. Treating these carefully chosen targets (you stay at the word level and the initial position of words) will result in the child correctly producing the sounds you're targeting as well as ones that you're not directly targeting (!!), resulting in faster progress and earlier dismissal from speech therapy.

Sounds pretty great, right?

kids in speech therapy

I highly recommend checking out both the article by Storkel from 2018 (referenced below) as well as the on-demand webinar on ASHA Learning Pass entitled, "Selecting Complex Intervention Targets for Children With Phonological Disorders" to get all of the details on this approach. Both also provide case studies that bring you through the process of choosing treatment targets. also offers comprehensive webinars on the complexity approach and its implementation as well. Free resources are also available on the site.

Below is my summary of the main elements of the complexity approach.

How is complexity determined?

According to Storkel (2018), the complexity of speech sounds is determined based on 4 factors:

  • Developmental norms: These are based on age of expected acquisition of speech sounds. Storkel refers to Shriberg's "middle 8" and "late 8" sounds for this (referenced below). Later-developing sounds are considered to be more complex and, therefore, better treatment targets.

  • Implicational universals: These are universal rules about the sound systems of languages. The idea is that treatment of "marked" sounds will lead to the development of "unmarked" sounds without the need for direct intervention. The universal rules for consonant singletons are:

Table with the universal rules for consonant singletons

As you can see from Storkel's table, affricates are more complex than fricatives, liquids are more complex than nasals, etc.

In addition, the complexity approach factors in two- and three-element consonant clusters. Sonority is an important factor when considering consonant clusters (remember those spectrogram readouts from grad school?). The lower the sonority difference between the consonants that make up a consonant cluster, the more marked, or complex, it is considered to be. Here is Storkel's table showing this:

a table showing the sonority difference of consonant clusters

  • The child's accuracy level: A sound the child cannot produce accurately is considered to be more complex than a sound the child can produce accurately.

  • The child's stimulability: A sound a child is not stimulable for is considered to be more complex than a sound the child is stimulable for.

Storkel provides stimulus probe pictures and Excel worksheets to help you determine targets here. The worksheets have codes built in so values will populate automatically to help you determine the best complex targets for your student.

While the complexity approach clearly requires much more analysis at the beginning of therapy, research shows that the payoff is big. Storkel also mentioned in her webinar that the treatment selection process gets faster and more intuitive the more you do it.

Here's hoping!


Did you find this blog post helpful? Subscribe below to get the latest blog posts, which feature lots of speech therapy ideas for busy SLPs who want to provide fun, impactful, and meaningful speech-language therapy.

Have you heard? StoryWhys now offers the Speech and Spell series of resources. I am always trying to tie articulation work and spelling together in my therapy and I've never found any good resources out there to help me do this. So I made my own! Many more speech sounds and spelling rules to come. They'll be 50% off for 48 hrs when new resources are added to the StoryWhys store. Find them here.

Did you know book companions can be among the best speech therapy materials for elementary students? Explore all of the StoryWhys book companions for speech therapy in my store. You'll find comprehensive book companions that target many different language skills or Spotlight Series book companions that focus on one type of skill, all using high-quality, beloved storybooks.

And get your FREE, 71-page book companion for speech therapy on the free download page.


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Shriberg, L. D., & Kwiatkowski, J. (1994). Developmental Phonological Disorders I: A Clinical Profile. Journal of Speech and Hearing Research, 37(5), 1100–1126.

Storkel HL. The Complexity Approach to Phonological Treatment: How to Select Treatment Targets. Lang Speech Hear Serv Sch. 2018 Jul 5;49(3):463-481.


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