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Dr. Caroline Ramsey Musselwhite

Monday, July 1, 2019

Drafting CVI Progress Charts for Emergent Readers

DRAFT — July 1, 2019 by Deanna K. Wagner, MS/CCC-SLP

I have been studying recommendations from many resources to begin the process of summarizing some information and hopefully providing some framework for team-based discussions for emergent literacy supports when students have been identified as having cortical visual impairments, or are suspected of having visual processing deficits in addition to other complex physical and cognitive impairments. According to Roman-Lantzy, (2018), there are 10 characteristics of CVI that are measured by the CVI Range, Rating II. The CVI Characteristics provide information about visual functioning and overall degree of impact in the following areas: color preference, need for movement, visual latency, visual field preferences, difficulty with visual complexity, light gazing, difficulty with distance viewing, atypical visual reflexes, difficulty with visual novelty, absence of visually guided reach.  We can use this information to consider how a student’s vision impacts his/her ability to choose a book and interact with the book for an extended period of time at his/her own pace. In order to completely address each of these characteristics, we need to be mindful of the adaptations we make considering the individual’s physical capabilities.  When an individual is at the emergent literacy stage (i.e., does not know all letters/sounds and can not independently access meaning from written materials), we need to find daily opportunities for shared reading and self-directed reading (Erickson, 2017).  During self-directed reading time, understanding the content of the book is not a pre-requisite. Spending time during shared reading is crucial to building joint attention and shared knowledge in order to build concepts and social-linguistic skills (Lueck & Dutton, 2015).

CVI Characteristics Progress Monitoring for Self-Directed Reading
Scoring guide according to Roman-Lantzy (2018), CVI Range Score II:
0: Full effect of the characteristic is present
.25: Behavior on this characteristic has begun to change or improve
.5: The characteristic is affecting visual functioning approximately half the time
.75: Occasional effect of the characteristic; response is nearly like that of individuals the same age
1: Resolving, approaching typical, or response is the same as others of the same age
Color preference

A lower score indicates the student attends best to a single, preferred color and may not be able to visually engage with more complex materials.
Ratings in the middle indicate the student can attend to more than one color (though bright fluorescent colors may be most engaging) and may benefit from highlighting visual features of both 2D and 3D items in a preferred color.  NOTE from DEANNA: These students may benefit from Experience Books with Tactile Enhancements using preferred color.
Ratings at the highest level indicate that a specific color is not required for visual engagement with a book.
Need for movement

Lower scores indicate the student attends primarily to movement (including being distracted by a ceiling fan).
Middle scores indicate that vision may be distracted by movements 8-10 feet away, but we can also use movement to bring their attention to a particular area where they can focus on a specific item (i.e., elements on the page of a book).
Highest scores indicate we don’t need movement to elicit visual engagement, but we should be aware of movements in the distance that could be distracting while trying to look at the pages of a book.
Visual latency

Lower scores indicate that the student takes a long time to look at an item, every time it is presented.
Middle scores indicate that the time can be reduced with familiarity, but shows up again when the person is fatigued or over-stimulated.  Expecting visual attention to a book following a seizure may not be realistic.
Higher scores indicate latency is not a factor very often, and they can look at a target when presented.
Visual field preferences

Lower scores indicate that the person struggles with lateral visual fields, affecting where we might position a book.
Middle range scores indicate visual fixations in more fields, though lower visual field function may remain atypical.
Higher scores indicate the student can visually fixate in all visual fields.  Students with CP almost never achieve a perfect score on this indicator due to challenges with lower visual field processing.
Difficulties with visual complexities

Visual complexity is evaluated as it relates to objects, array, sensory environment, and faces.  Lower scores indicate visual attention can be focused on a single-colored near object when there are no competing sensory inputs (including overhead lights).  
Middle range scores indicate the ability to attend to more details or more items at once is improving, though competing sensory input is still visually distracting.  Using backlighting can engage vision.
Scores at the highest level indicate that the student can attend to complex visual arrays even in environments with competing sensory input.
Need for light

Lowest scores indicate that the student attends to sources of light to the point of visual fixation and has trouble looking away from bright lights.
Middle range scores indicate that light can be used as a tool to engage/direct vision (such as through use of a light box or back-lit tablet).
Higher scores may indicate that visual recognition or discrimination may be enhanced by backlighting and there may not be as many difficulties with visual fixations unless the person is tired, hungry, or immediately following a seizure.    
Difficulty with distance viewing

Lower scores on this indicator would indicate best viewing is at a distance of less than 18 inches.
Middle range scores indicate ability to visually attend to items as far away as 10 feet, especially if they are moving (such as recognizing a person who is moving in the distance).  
Higher scores indicate that distance is not a problem for this individual, and is rare for students with CVI.  We should assume that reading books should take place using near vision when possible and without distractions of objects that are moving in the distance.
Difficulty with visual novelty

Low scores indicate the student prefers to look at items that are familiar and is not curious about new things.
Middle scores indicate visual curiosity is growing.  Building visual curiosity can be an important target for bookreading.  Visual curiosity is built from experiences with objects, and does not occur spontaneously with 2D images.  
Higher scores indicate a student is able to use vision to learn about new things.
Absence of visually guided reach

A student scores lowest on this characteristic if he looks, looks away, and then reaches for an item (separate rather than integrated actions).  
Scores in the middle indicate more integrated function of looking and reaching, sometimes facilitated by use of bright or shiny/moving objects.  
This indicator is scored at the highest level for students with motor impairments if their attempts to target an item include visual attention on the item as they are reaching. Problems with visually guided reach may be minimized when we use eye gaze selection on a tablet or computer.   
Atypical visual reflexes

Lowest score means the student doesn’t blink in response to a quick poke at the area just between the eyes at the bridge of the nose (or other visual threat).
Middle scores indicate the blink response to visual threat is inconsistent.
Most students with CVI have an abnormal blink reflex.  It is not something we target for educational interventions.  


Erickson, K. (2017). Comprehensive Literacy Instruction, Interprofessional Collaborative Practice, and Students With Severe Disabilities. American Journal of Speech-Language Pathology, Vol. 26, pp 193–205, May 2017. Downloadable from: https://pubs.asha.org

Lueck & Dutton, Eds. (2015). Vision and the Brain: Understanding Cerebral Visual Impairment in Children. AFB Press.

Roman-Lantzy, C. (2018). Cortical Visual Impairment: An Approach to Assessment & Intervention. AFB Press, 2nd Edition. ISBN-10: 0891286888; ISBN-13: 978-0891286882

Wednesday, June 26, 2019

AAC in the Cloud Presents - Stories of Ourselves: Family Photo Fun

Anybody looking for the slides from this session, please click here

To watch the recorded session on YouTube, please click here

Monday, June 17, 2019

Stories of Ourselves: Building Social-Linguistic Skills of Learners with CVI

Five broad instructional strategies are emphasized in the trifocus framework as synthesized by Bruce and Bashinski (2017): enhancing (partner) sensitivity, utilizing routines, increasing communication opportunities, modifying the communication environment, and augmenting input. Stories of ourselves are a great context for all 5 of these strategies.  

Enhancing partner sensitivity involves understanding how a learner responds to the world around him/her.  Visual (and auditory) processing difficulties may result in behaviors that appear defiant or non-functional.  The term CVI has been used to refer to Cortical Visual Impairments (Roman-Lantzy, 2017, 2018) and Cerebral Visual Impairment (Lueck & Dutton, 2015).  Both terms refer to visual processing challenges that are the result of brain damage rather than damage to the eyes.  We use the term CVI when referring to learners of any age who appear to have normal visual structures, but function in ways that point to problems processing  their visual world.  This affects their ability to safely move around the environment, manipulate objects, watch what other people are doing, and even notice facial expressions.  For those whose brain damage also results in severe physical impairments, it can be difficult to determine how and what they are seeing and hearing.  Fortunately, a team-based approach can heighten awareness and empathy of those surrounding this person, and result in strategies and experiences that can result in real changes to brain function and systematic improvements in social-linguistic skills.  Stories of ourselves can be used to build awareness of how a person functions in his/her world.  During shared reading (Erickson, 2017), partners can be more aware of the visual processing challenges posed by expecting somebody to read facial expressions, look where somebody is pointing, and recognize images on the page.  Only when we are empathetic and sensitive to the challenges can we make appropriate accommodations.  

Utilizing routines can be a tremendous comfort to learners with sensory processing impairments.  Understanding that an activity has a beginning and an end can build confidence to explore.  Stories of ourselves can be used as a way to talk about routine activities.  Deaf-Blind literacy resources suggest use of “Experience Stories” and “Experience Books” as a way to share and review what has happened, while at the same time building new concepts (example here: https://www.wsdsonline.org/video-experience-books/).  In this way, our stories build social-linguistic connections.  Bridge School experts recommend using Home News as a routine for home-school connections (http://curriculum.bridgeschool.org/areas/cc/strategies/connections/homenews).  Sharing a brief personal story within a predictable routine can build social-linguistic skills by incorporating the recorded voices of family members and friends in a context that is relevant and meaningful.  Family bedtime stories can become part of a routine that provides a quiet environment with relatively few distractions.  Routines that incorporate movement and rhythm can also result in short stories about ourselves and what we are doing, and can be sung throughout the day.  Consider Musselwhite’s songboard, “Take the Hat” (currently under revision) and familiar children’s songs like, “I like to eat, eat, eat apples and bananas.”  Consider the attendance routine in preschool when students greet each other with song and movement (Musselwhite, 2015).  The amount of movement and activity can be a sensory overload for some with visual and auditory processing challenges.  Offering this activity during a quiet one-on-one shared reading time, reviewing a story about who came to school today, may allow some learners time to process and attend in a more meaningful way. 

Increasing communication opportunities is the third strategy in the tri-focus approach.  When a student feels safe and secure, he/she is more likely to reach out and explore the world.  Careful observation of self-directed movement and signs of engagement can be key to building joint attention.  Partners need to recognize communication styles and build personally meaningful experiences through joint attention.  Since students with CVI may not have access to the same visual signals as their peers (or partners), we need to carefully consider how to engineer communication opportunities that foster learning social-linguistic patterns.  Building on the idea of maintaining an attitude of empathy and utilizing routines, communication can take place when something unexpected happens.  Stories of ourselves can be a way to talk through the “what if” scenarios.  We can structure personal stories with clear conversational contexts.  For example, a story about what we do when it is time for lunch can help a learner identify environmental cues about lunch time and gain explicit instruction from the story about what he or she could do to let somebody know what he is thinking at the time.  Quite possibly school lunch routines are heavy on sensory input that involves lots of movement, and can be overwhelming for a student with CVI.  Rather than expecting the student to activate a message on a communication device that says, “I am hungry” when it is time for lunch, we need to consider carefully what the person is telling us by his/her responses to the environmental cues.  We can use a personal story that reflects on how somebody might feel and what choices might be offered.  Careful identification of motivators will help conversational partners identify communication opportunities.  However, we need to keep in mind that requesting a motivator is only one function of communication.  Opportunities to complain, question, and comment may need to be strategically planned.  In this way, the context of a personal story can be used to build social-linguistic skills. 

Modifying the communication environment for students with CVI may include reducing competing sensory information and reducing the complexity of visual information (Tietjen, 2019).  Different strategies may be appropriate, depending on the level and severity of CVI.  Using the results of the Range for CVI (Roman-Lantzy, 2018) and recognizing the potential for change over time can result in significant changes in social-linguistic connections.  Some students with less severe CVI may benefit from consistently-worded descriptions of key visual features of elements in their environment.  Communication partners who are sensitive to sensory needs and necessary adaptations can find meaningful ways to use movement and auditory signals separate from visual processing requirements.  We need to recognize that some students with CVI turn away or close their eyes when they are really paying attention to choices being offered through auditory channels.  Stories of ourselves can be used to inform others about what the learner does when listening to choices.  Through personalized stories, we can describe environmental adaptations that provide a secure environment that facilitates personal expression and engagement.  

Augmenting input is often understood to mean pointing to symbols on an AAC system as we speak.  Some learners with CVI may not be able to see what the person is pointing at or to visually recognize the referent.  In this case, the “augmentative input” is not matched to personally meaningful social-linguistic constructs.  We may actually be introducing elements that result in increased stress.  To avoid toxic stress, Scoggin (2018 Fall Special Topics Workshop, Connections Beyond Sight and Sounds) recommends building a feeling of competence by giving the learner time to process information through channels that are accessible and personally meaningful to him/her, building anticipation based on familiar routines and interests, waiting for the individual to initiate movement, following the child’s lead, and imitating what he/she does.  When an individual has something to say and does not use symbolic language, we can notice the way they orient their bodies and use their vocal expressions to the best of their abilities (Communication Matrix).  Rather than expecting the person with CVI to imitate a communication partner, the partner also needs to learn how to mirror the communication skills of the individual.  Therefore, augmented input can vary from individual to individual.  For those with the most severe levels of CVI, input may be primarily auditory.  But if the student has some functional vision, we need remember to include that as an anchor that can build joint attention.  Augmenting input can come in the form of drawing attention to visual information through an auditory channel.  Stories of ourselves can be used as the context for providing a concrete visual anchor while we introduce ways to access auditory messages to talk about the item.  For example, a story about a favorite toy can include a concrete representation of the toy.  During shared reading about a personally meaningful item/event, visual attention may be focused on the item in the book.  For some this may require a physical connection with some tactile elements of the toy/event. Once we have established a joint reference, we can use a story to provide examples of how a child may respond to choices from an auditory scanning system.  A robust auditory scanning system must incorporate multiple communicative functions.  Using a story that explains what can happen when a learner indicates that he/she “has something to say about that,” and chooses one of the auditory options, can explicitly and selectively demonstrate communicative branching to build social-linguistic connections.  For example, in the context of reading a story about playing with his/her favorite brightly colored ball, auditory branching from the communication system may offer choices such as: me/mine, want, more, like, questions, all done, you/yours.  Using a PODD auditory scanning book can provide consistent structure to a branching system (explore resources from Porter, Burkhart, and Farrall). Therefore, a personal story may include what happens when the learner selects the auditory option for “me/mine” and is given the ball to play with.  After some time interacting with the ball, the partner waits for attention to return to the story before going on to the next page.  Giving the student a way to turn the page electronically may be the best way to signal that he/she is ready to move on.  The next page of the book can show the same ball, but this time signal that a different auditory option can be selected.  The context of the book, therefore, offers a concrete structure for choosing a different item from the auditory scanning options and expands experiences.  If the individual does not select a different item from the auditory list, the communication partner may need to demonstrate this.  Turning to the next page can be like choosing the second item from an auditory scan (e.g., recurrence).  Then when it is time to go to the third page, the auditory scan can again be initiated and used to signal that this book is about what happens when the third item in the list is selected (e.g., commenting - leading to expressions of pleasure).  A fourth page can demonstrate choosing another branch (e.g., questioning - leading to asking who/where).  The last page in the book can demonstrate what happens when we choose a termination message (e.g., all done).  

So there you have it!  When we use principles that incorporate a tri-focus approach, and apply that to personally meaningful and accessible learning opportunities, we can put in place a plan that addresses the needs of all students, including those with CVI.


Bridge School experts (unnamed and undated) recommend using Home News as a routine for home-school connections.  http://curriculum.bridgeschool.org/areas/cc/strategies/connections/homenews  

Bruce & Bashinski (2017).  The Trifocus Framework and Interprofessional Collaborative Practice in Severe Disabilities.  Published by American Journal of Speech-Language Pathology, Copyright ASHA.  Download from https://doi.org/10.1044/2016_AJSLP-15-0063 

Burkhart (undated).  PODD links for ordering, handouts, and workshops.  http://www.lindaburkhart.com/podd.htm

Communication Matrix (undated).  www.communicationmatrix.org 

Erickson, K. (2017). Comprehensive Literacy Instruction, Interprofessional Collaborative Practice, and Students With Severe Disabilities. American Journal of Speech-Language Pathology, Vol. 26, pp 193–205, May 2017. Downloadable from: https://pubs.asha.org 

Farral, J (2019). Literacy, AAC and Assistive Technology.  Resource includes links to workshops and blog posts.  For 2015 PODD Tips from Interactive Speech Pathology, link to http://www.janefarrall.com/getting-hands-on-with-podd/ 

Lueck & Dutton, Eds. (2015).  Vision and the Brain:  Understanding Cerebral Visual Impairment in Children.  AFB Press. Includes Chapter 4 by Fazzi, Moliaro & Hartmann, titled: “The potential impact of visual impairment and CVI on child development.” AFB Press.  ISBN-10: 089128639X; ISBN-13: 978-0891286394.

Musselwhite (currently under revision).  Singing to Learn CD.  Order form http://www.aacintervention.com/home/180009852/180009852/docs/Software%202-06.pdf 
Based on Caroline’s Tips 1-4 from 2015.    http://www.aacintervention.com/page/180009852/180103625/2015-TIPS-1-4

Porter, G.  (2009). Pragmatic Organization Dynamic Display (PODD) Communication Books: A Promising Practice for Individuals With Autism Spectrum Disorders. Article from Perspectives on Augmentative and Alternative Communication 18(4):121-129 · December 2009. DOI: 10.1044/aac18.4.121

Roman-Lantzy, C. (2018). Cortical Visual Impairment: An Approach to Assessment & Intervention. AFB Press, 2nd Edition. ISBN-10: 0891286888; ISBN-13: 978-0891286882

Roman-Lantzy, C. (2019). Cortical Visual Impairment Advanced Principles.  Including chapter by
Mark Tietjen on “What’s the Complexity” Framework. AFB Press. ISBN-10: 1616480076; ISBN-
13: 978-1616480073

Scoggin (2018).  Part of the annual Technical Assistance training opportunities offered by Connections Beyond Sight and Sounds. This event was originally scheduled as the 2018 Summer Institute, but due to logistics, was rescheduled as the 2018 Fall Special Topics Workshop. “Emergent Literacy Ideas for Complex Learners” — presented by Kathee Scoggin.  Downloadable PPT and other materials from the workshop can be found here:  http://marylanddb.org/2018/05/08/2018-summer-institute-registration-open/

Washington Sensory Disabilities Disabilities Services (undated).  What is an “experience book?” Found at https://www.wsdsonline.org/video-experience-books/ 

Tuesday, April 16, 2019

It’s Imperative! Listening in on Spanish Conversations Out and About, AAC in our Community

In English-speaking homes in Arizona, parents communicative interactions with young children use many declarative statements (you like that) and interrogatives (do you like that).  I have noted that many Spanish-speaking parents here in Arizona use language with their young children that is quite loaded with imperatives.  This would be a great language study for somebody!  For now, I only have anecdotal reporting to rely on.

Many of us have witnessed periodic use of these imperative phrases, sometimes at a Mexican restaurant, the supermarket, or even on the playground.  In Spanish the grammar markers are so important they are included before and after exclamations.  Check out the images I found using my Bitmoji!

¡Mira! = Look!
¡Ven! = Come here!

Here are 3 more examples, some of which may not be recognizable to people who are not familiar with Spanish.  Would you be able to match these images to the imperative statements?
¡Dámelo! = Give me that!

¡Díme! = Tell me!

¡Ayúdame! = Help me!

Aided language input is a process of pointing to symbols as we speak, as a method to share meaning and grow expressive abilities of people who have limited verbal speech.  To reflect what parents are telling their children, the communication systems we use should also incorporate these forms: declarative, interrogatives and imperatives.

Take a look at the AAC systems you are currently using with your students, and reflect on whether they are truly robust and offer language experiences that will help the people we are supporting to build skills.  Here are a few links to AAC communication displays that you can download and try out:

Considering bilingual English/Spanish AAC options?

We are constantly growing our lexicon and thinking of new ways to share ideas with others. Think about how we use words and language.  Be careful not to judge others for the choices they make about how to share their ideas.

Most importantly - Have fun! 

Practical ideas and tips on bilingual issues and AAC can be found here - 

Also, please check out a core vocabulary resource that I created, 40 Spanish Words in 4 Months, at www.aacintervention.comhere (Tip #5).


Wagner, D. K., (2018, November). Building Augmentative Communication Skills in Homes Where English and Spanish Are Spoken: Perspectives of an Evaluator/Interventionist, Perspectives on AAC, 3, 172-185.  Download link:  https://pubs.asha.org/doi/10.1044/persp3.SIG12.172 

Friday, March 15, 2019

Book Creator: Create, Read and Publish

Book Creator
Create, Read, and Publish

Students who are developing literacy skills need daily opportunities to use/practice with letters, select words from their AAC systems, read books of their own choice, and write for authentic purposes and audiences.  Book Creator is a great tool for this.  Here are a few websites from those who use Book Creator with students who have complex communication and emergent literacy instructional needs.  
Find the Book Creator sample books by category.  LINK:  https://bookcreator.com/resources-for-teachers/example-books/ 

This post by Diane Brauner, August 2016, provides tips and examples for students with vision impairments.  TITLE: Book Creator App: Create Your Own Accessible Books on iOS, Android and Windows Tablets.  LINK: http://www.perkinselearning.org/technology/posts/book-creator-app-create... 
The image below shows page editing overview in the iPad app.  We added personal images, text and recordings.  You can choose the color for the page and text.  Before adding photos, be sure to markup and modify as needed to draw attention to visual information in the image.

And from Tracy Wilkes, March 2019, we learn even more about sending home books, publishing and making school libraries. TITLE:  Using Book Creator To Make Engaging Literacy Materials.  LINK: http://www.pathstoliteracy.org/technology/using-book-creator-make-engaging-literacy-materials 
Here is an image of a published story written by Alexa, one of our participants in our Out and About AAC in the Community events.  LINK:  https://read.bookcreator.com/iM9O0VXRYMQ6IXWYCkCaLsFee882/S-QK7waLShOaagInaXubJw

Jon Smith posted this on the Book Creator site, January 2014, sharing that not only can you post stories written with and by students who have autism, but you can also track where they are downloaded on a map.  TITLE:  Using Book Creator to support students with autism.  LINK:  https://bookcreator.com/2014/01/using-book-creator-support-autistic-students/ 

WriteOurWorld.org is a US-based charity, supported by Book Creator, that empowers multilingual youth worldwide to embrace their languages and cultures while building skills for their future through digital book authoring.  Explore a growing inventory of multicultural ebooks created by kids for kids. You can read and listen in two languages!

Friday, March 8, 2019

CVI Resources Follow-up to AAC in the Desert 2019

 Compiled by Dorney, Hanser, Sheldon, Musselwhite & Wagner

Following AAC in the Desert, 2019, this list was composed for people who are interested in learning more about how to support the language and literacy skills of students who have Cortical Vision Impairments (CVI).  We have also included links that Kathryn Dorney shared on the Facebook Group AAC for SLPs.

Our Presentations and Publications:
  • Hanser & Wagner, ATIA 2018 & 2019.  Using PowerPoint to Adapt Books for Students with CVI 
  • Hanser, Tips for 2017. www.aacintervention.com Tip #7:  Making PowerPoint Books for Students with CVI
  • Wagner, ISAAC 2018.  Using PowerPoint Books to Support Communication & Literacy for Students with CVI
  • Wagner, Tips for 2018. www.aacintervention.com Tip #6: Building Vision for Communication, An Example for PHASE I Applications. Tip # 7: Integrating Vision with Communication, Examples for PHASE II CVI

Resources for Collaborative Input

CVI Webinars & Videos

CVI Websites for Continuing Ed, Tips and Ideas

  • Drawing from the work of Gordon Dutton, and including ideas and strategies shared by parents, caregivers and those affected by CVI, this website provides information about visual characteristics and profiles for CVI, processing at different levels of the brain, and functional vision.  Language learning emphasis is on the individual, drawing from experiences that are perceivable, meaningful and motivational, in order to build knowledge and understanding https://cviscotland.org/documents.php
  • WonderBaby.org is dedicated to helping parents of young children with visual impairments as well as children with multiple disabilities. Here you’ll find a database of articles written by parents who want to share with others what they’ve learned about playing with and teaching a blind child, as well as links to meaningful resources and ways to connect with other families. http://www.wonderbaby.org/  

Look for Some Electronic Books...

CVI Friendly Book Authoring Apps
  • Pictello App (currently $19.99)
  • Book Creator App (currently $4.99) 
  • Explain Everything App ($13.99 Explain EDU version)

Downloading/Resizing Videos


Bruce & Bashinski (2017). The Trifocus Framework and Interprofessional Collaborative Practice in Severe Disabilities. American Journal of Speech-Language Pathology, Vol. 26, pp 162–180, May 2017. Copyright © 2017 American Speech-Language-Hearing Association. Downloadable from: https://pubs.asha.org

Erickson, K. (2017). Comprehensive Literacy Instruction, Interprofessional Collaborative Practice, and Students With Severe Disabilities. American Journal of Speech-Language Pathology, Vol. 26, pp 193–205, May 2017. Downloadable from: https://pubs.asha.org

Justice, L. M., & Pullen, P. C. (2003). Promising interventions for promoting emergent literacy skills: Three evidenced-based approaches. Topics in Early Childhood Special Education, 23, 99-113.

Porter, G., & Burkhart, L. (2010). Limitations with using a representational hierarchy approach for language learning. Retrieve from http://www.lburkhart.com/handouts/representational_hierarchy_draft.pdf 

Roman-Lantzy, C. (2018). Cortical Visual Impairment: An Approach to Assessment
& Intervention. AFB Press, 2nd Edition. ISBN-10: 0891286888; ISBN-13: 978-0891286882

Roman-Lantzy, C.  (2019). Cortical Visual Impairment: Advanced Principles 
(Includes chapter by Mark Tietjen on “What’s the Complexity” Framework).  
American Printing House for the Blind..  ISBN-10 / ISBN-13: 1616480076 / 978-1616480073