AAC Research

Core Words vs Fringe Words in AAC: The Difference, the Research, and How to Balance Both

STSabiKo Team
January 9, 202614 min read
AACcore vocabularyfringe vocabularycore wordsfringe wordsresearchSLPlanguage development

If you've been reading about AAC or talking with a speech-language pathologist, you've probably heard the terms "core words" and "fringe words." These two categories describe different types of vocabulary, and understanding the difference is one of the most practical things you can learn as a parent, teacher, or therapist supporting someone who uses AAC.

This guide covers what each type is, what the research actually says about prioritizing core vocabulary, how core-word device layouts compare to noun-based ones, and which fringe words to add for the activities in your child's life.

What Are Core Words?

Core words are a small set of high-frequency words that people use constantly in everyday conversation. They show up in every topic, every setting, and every age group. Linguists sometimes call them "function words" because they serve as the building blocks of sentences.

Characteristics:

CategoryExamples
PronounsI, you, it, my, that, this
Verbswant, go, get, put, make, help, like, see, look
Adjectivesmore, big, little, good, different, same
Prepositionsin, on, up, off, out, with
Negationno, not, don't
Social wordshi, bye, please, thank you, yes
Determinersthe, a, some, all

What Are Fringe Words?

Fringe words (also called "fringe vocabulary" or "extended vocabulary") are topic-specific words that carry concrete meaning. They tend to be the nouns and proper nouns that name specific people, places, things, and ideas.

Characteristics:

CategoryExamples
Foodcookie, apple, juice, pizza, milk
Animalsdog, cat, fish, dinosaur, horse
Peoplemom, dad, grandma, teacher, friend's name
Placesschool, park, store, home, playground
Toys/activitiesball, blocks, iPad, swing, bike
Clothingshoes, hat, jacket, socks

Side-by-Side Comparison

DimensionCore WordsFringe Words
FrequencyVery high (majority of daily speech)Lower (minority of daily speech)
FlexibilityWork across all topics and settingsTied to specific topics or contexts
Word typesVerbs, pronouns, adjectives, prepositionsMostly nouns and proper nouns
Number needed200 to 400 words cover most communicationThousands of words, constantly growing
AbstractnessOften abstract ("more," "not," "that")Usually concrete ("cookie," "dog," "park")
Symbol representationHarder to represent with picturesEasier to represent with pictures
Sentence buildingForm the structure of sentencesFill in the specific content
PersonalizationSame for everyoneUnique to each person's life
Teaching approachModel across many contexts all dayTeach in relevant moments and activities

How They Work Together

Core words and fringe words aren't competing categories. They're partners. Every meaningful sentence combines both types.

Core words appear in almost every sentence, providing the grammatical glue. Fringe words drop in to specify the topic. You need both, but if you had to prioritize, core words give far more communicative power per word learned.

A child who learns 20 core words can build hundreds of different sentences. A child who learns 20 fringe nouns can label 20 things but can't yet ask for them, refuse them, describe them, or talk about them in any flexible way.

What the Research Says

The research on core vocabulary is some of the most consistent and practically applicable evidence in the entire AAC field.

The frequency numbers

Yorkston, Dowden, Honsinger, Marriner, and Smith (1988) conducted one of the earlier frequency analyses for AAC purposes. They found the 100 most frequently occurring words covered approximately 60% of all words spoken in their samples. The top 500 covered roughly 80%.

Banajee, DiCarlo, and Stricklin (2003) studied toddlers aged 2 to 3 in daycare settings. They found roughly 250 words accounted for the vast majority of the children's communication, and most were core vocabulary, not the object labels many early AAC systems emphasized.

Baker, Hill, and Devylder (2000) analyzed vocabulary use across multiple environments and found core words remained consistent regardless of where communication happened.

Cross, Baker, Klotz, and Badman (1997) confirmed that a small core set is remarkably stable across ages, contexts, and ability levels.

Binger, Magallanes, San Miguel, Harrington, and Hahs-Vaughn (2024) examined how toddlers combine core and fringe words in natural utterances, reinforcing that even very young children rely heavily on core words to build multi-word combinations, with fringe words serving as content anchors.

Why core words are more powerful than nouns

Generativity. Core words combine with each other and with fringe words to produce an almost unlimited number of messages. "Want" + any noun = a request. "Not" + any word = a negation. A child who knows 10 core words and 5 nouns can produce dozens of unique messages. A child who knows 15 nouns can label 15 things.

Context independence. "Cookie" is relevant at snack time but useless on the playground. "More" is useful during meals, play, reading, music, and bath time. Core words travel with the child from setting to setting.

Motor planning efficiency. On a communication device, each word lives at a specific screen location. With consistent placement, users develop motor plans that let them navigate without visually searching. A child who uses "more" 20 times a day develops a fast, automatic motor plan within weeks. A noun used once a day may never develop that automaticity. AAC systems like SabiKo that keep core words in consistent positions support this.

Does teaching core words improve outcomes?

Boenisch and Soto (2015) analyzed the oral vocabulary of typically developing school-age children and confirmed that a small set of core words dominated everyday speech across all children studied. This matters because it shows the core vocabulary pattern isn't an artifact of simplified communication systems. AAC systems built around core words aren't limiting. They're mirroring the structure of natural language.

Clendon and Andersen (2017) presented a case study of a literacy-based AAC intervention incorporating core vocabulary. The participant showed increases in both the frequency and diversity of communication.

Trembath, Balandin, and Togher (2007) studied vocabulary selection across Australian English and Italian contexts, finding that core vocabulary provides a stable foundation across different languages and cultural settings.

Core-Word Layouts vs Noun-Only Layouts

The core/fringe distinction shows up directly in how AAC devices are organized, and the two philosophies produce very different results.

A core vocabulary system puts high-frequency words on the home screen: pronouns (I, you, it, my, that), verbs (want, go, like, make, get, put, help), adjectives (more, big, little, good, not, all), social words (yes, no, hi, please), and question words (what, where, who). Nouns live on secondary pages. The words you need most often require the fewest button presses. LAMP, Unity by PRC, PODD, and Proloquo2Go's Crescendo all work this way.

A noun-based system organizes the home screen around topics: Food, Drinks, Animals, People, Places, Toys, Colors, Body parts. Tapping a category opens a page of nouns. Action and descriptive words are usually buried in their own category or scattered across pages.

The problem with noun-first organization

Labeling without communicating. A child who points to a picture of "juice" is labeling. Are they requesting juice? Commenting that there is juice? Telling you they don't want juice? Asking where it is? Without core words, the partner has to guess.

Limited communicative functions. A system built primarily around nouns supports requesting and maybe commenting. It does very little for anything else:

FunctionCore Words NeededNoun-Only Equivalent
Requesting"want," "more," "please"Point to desired item (limited)
Refusing"no," "stop," "don't want"No clear equivalent
Commenting"look," "I see," "big," "funny"Point to item (ambiguous)
Asking"what," "where," "who"No equivalent
Greeting"hi," "bye"No equivalent
Protesting"no," "stop," "not," "yucky"No clear equivalent
Directing"go," "put," "come," "help"No equivalent

Vocabulary ceiling. Noun-based systems hit a ceiling quickly. Each noun only adds one more label. Core vocabulary systems scale differently: each new core word multiplies the possible combinations, so communicative power grows exponentially rather than linearly.

Constant customization required. A noun-organized system needs different vocabulary for the kitchen, classroom, playground, doctor's office, and grandma's house. Core words are useful everywhere, so the customization burden is much lower.

For a broader guide to evaluating apps, see choosing the right AAC app.

Transitioning from a noun-heavy setup

You don't need to throw everything out and start over.

  1. Add core words to the home screen. Most apps let you customize the home page. Add 5 to 10 high-frequency core words alongside existing categories.
  2. Start modeling the core words. When your child points to "cookie," model "want cookie." When they point to "outside," model "go outside."
  3. Keep the nouns accessible. Your child knows where they are and relies on them. Just don't let them be the only thing on the home screen.
  4. Gradually increase core word access. Over time, consider switching to a core-word-first layout if your app supports one.
  5. Give it time. Your child may initially seem less fluent because the layout changed. That's normal. Most children adapt within a few weeks.

Fringe Vocabulary Ideas by Activity

Core vocabulary gives your child the structure of language. Fringe vocabulary gives them the content. "I want" is a powerful phrase, but "I want trampoline" is a complete, actionable message. Children are also more motivated to communicate about things they care about.

These lists are starting points, not prescriptions. Your child's fringe vocabulary should reflect their actual life.

Mealtime. cookie, apple, juice, milk, water, pizza, crackers, banana, spoon, plate, bowl, napkin, hungry, full, yummy. See AAC during mealtimes.

Bath time. bubbles, water, towel, soap, duck, boat, shampoo, splash, wash, pour, wet, warm, cold, dirty, clean.

Playground and outdoor play. slide, swing, ball, sand, bike, climb, push, kick, throw, run, jump, dig, catch, high, fast. See AAC at the playground.

School and classroom. teacher, pencil, paper, scissors, glue, backpack, crayon, computer, recess, lunch, circle time, homework, line up, draw, color. See talking to school about AAC.

Getting dressed. shirt, pants, shoes, socks, jacket, hat, zipper, button, underwear, pajamas, dress, boots, tight, itchy, favorite.

Grocery store. cart, basket, bread, cheese, eggs, cereal, fruit, vegetables, ice cream, chicken, bag, money, checkout, heavy, buy. See AAC at the grocery store.

Doctor and dentist visits. doctor, nurse, dentist, medicine, shot, sticker, thermometer, bandage, teeth, toothbrush, tummy, hurt, sick, scared, brave. See AAC at the doctor's office.

Holidays and birthdays. cake, candle, present, balloon, party, costume, pumpkin, tree, egg, card, sing, wrap, blow, surprise, celebrate.

Bedtime. bed, pillow, blanket, teddy, book, light, story, dream, night-night, lullaby, sleepy, dark, cozy, scared, hug.

Favorite hobbies and interests. music, paint, swim, dance, build, puzzle, movie, game, song, drum, car, train, horse, robot, sticker. This is the most personal category. Replace these with whatever your child actually loves.

Practical Tips for Balancing Both

Start with core words, then layer in fringe. Begin with high-frequency core words your child can use across situations. Once those are becoming familiar, add fringe words that matter to their daily life. See how to teach core words.

Model both types throughout the day. During snack time, model "I want crackers" (core + fringe) or "more juice please." Show how core words combine with fringe words to create real communication. See AAC modeling at home.

Customize fringe vocabulary before activities. Going to the park? Make sure "swing," "slide," and "sand" are accessible. Core words stay the same across situations. Fringe words change.

Don't overload the system with nouns. A child with 200 food labels but no way to say "want," "don't like," or "more" can only point to pictures of food.

Follow your child's interests for fringe words. If they love trains, "train," "track," and "fast" belong on the device long before "stethoscope." Motivation drives learning.

Add five to ten fringe words at a time. Give your child a chance to learn where they are before adding more. Adding 50 at once makes the device cluttered and harder to navigate.

Revisit fringe words regularly. Core words are stable and you'll teach the same ones for years. Fringe words need updating as interests change, seasons shift, and new topics come up at school.

Ask their therapist and teachers. SLPs and classroom teachers see your child in contexts you might not, and can identify vocabulary relevant to school routines and peer interactions.

The Bottom Line

The evidence consistently supports organizing AAC systems with core words as the primary, most accessible vocabulary. Core words are the engine of communication: small in number, massive in impact, and they work everywhere. Fringe words are the color and detail that make communication personal and specific.

Your child doesn't need to choose between core and fringe vocabulary. They need both, working together, with core words as the foundation.

For a full reference of core words to include, see the core words list for AAC. For strategies and activities, see how to teach core words.

References

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