Dependent Tiers

Status: Reference Last updated: 2026-04-09 08:40 EDT

Dependent tiers appear on lines beginning with % immediately after an utterance. They provide annotations linked to the main tier content.

CHAT defines four structural categories of dependent tiers:

1. Structured linguistic tiers — parsed into typed AST nodes with word-level alignment
2. Phon phonological tiers — syllabification and segmental alignment from the Phon project
3. Bullet-content tiers — free-form text with optional inline timing markers
4. Text tiers — plain text with no structural alignment

Structured Linguistic Tiers

These tiers have rich, parsed representations in the data model. Each token aligns 1-to-1 with an alignable word on the main tier (excluding retraces, pauses, and events). Terminators (., ?, !) must match the main tier terminator.

%mor — Morphological Analysis

The %mor tier carries part-of-speech tags, lemmas, and morphological features for each word on the main tier. See The %mor Tier for full documentation covering the UD-style format, data model, divergences from Universal Dependencies, and migration from traditional CHAT MOR.

Format: POS|lemma[-Feature]*, with ~ separating post-clitics.

*CHI:	she's eating cookies .
%mor:	PRON|she~AUX|be-Pres-S3 VERB|eat-Prog NOUN|cookie-Plur .

%gra — Grammatical Relations

The %gra tier encodes dependency syntax using Universal Dependencies relation labels. Each entry has the format index|head|relation, where indices are 1-based and head 0 indicates ROOT.

*CHI:	I want cookies .
%mor:	PRON|I VERB|want NOUN|cookie-Plur .
%gra:	1|2|SUBJ 2|0|ROOT 3|2|OBJ 4|2|PUNCT

The %gra tier aligns with %mor chunks (clitics expand into multiple chunks). Validation checks sequential indices (E721), ROOT structure (E722 missing root, E723 multiple roots), and circular dependencies (E724).

%pho / %mod — Phonological Transcription

The %pho tier records actual pronunciation; %mod records target/model pronunciation. Both use the same format: space-separated phonetic tokens aligned 1-to-1 with main tier words.

*CHI:	I want three cookies .
%pho:	aɪ wɑnt fwi kʊkiz .
%mod:	aɪ wɑnt θri kʊkiz .

Phonological tiers support IPA, UNIBET, X-SAMPA, or custom notation systems. They are used for child language, speech disorders, L2 learning, and dialectal variation studies.

Parsing strategy: We deliberately parse only the minimal word/group-level structure in %pho and %mod needed for coarse alignment with the main tier. The full IPA phoneme content is stored as opaque strings — deep phonological analysis is handled by Phon, and we avoid duplicating that work. The Phon extension tiers (%modsyl, %phosyl, %phoaln) follow the same strategy.

%sin — Gesture and Sign Annotation

The %sin tier codes gestures and signs aligned with speech. Each token is either 0 (no gesture) or g:referent:type (e.g., g:ball:dpoint for a deictic point at a ball).

*CHI:	that ball .
%sin:	g:ball:dpoint 0 .

Multiple simultaneous gestures use bracket grouping: 〔g:toy:hold g:toy:shake〕.

%wor — Word Timing

The %wor tier carries word-level timing annotations for media synchronization. Words may include inline bullets with millisecond timestamps. Word text is display-only (“eye candy”) — timing data comes from the bullet fields.

%wor is not a flat “all tokens except punctuation” tier. It follows a word-level alignment rule:

• Regular words count.
• Fillers (&-um, &-uh, &-you_know) count — they are real spoken words with known phoneme sequences.
• Fragments (&+...) do NOT count — incomplete phoneme sequences; the FA engine cannot reliably anchor partial phonological material.
• Nonwords (&~...) do NOT count — interactional/gestural sounds without stable lexical phoneme content for alignment.
• Untranscribed placeholders (xxx, yyy, www) do NOT count — they have no known phoneme sequence; CTC forced alignment cannot produce timings for unknown material.
• Replacements keep the original spoken word slot for %wor; the replacement text matters for %mor, not %wor. If the original slot is untranscribed or a fragment/nonword, it is still excluded.
• Retrace scope does not change %wor membership.
• Overlap markers do not change %wor membership.

%wor is a timing-annotation tier. Its word count equals the number of Wor-domain words and may differ from a naive main-tier word count. There is no downstream positional indexing into %wor; the %wor count is not validated against the main-tier word count.

*CHI:	I want cookies .
%wor:	I want cookies .

Exact corpus-shaped contrast:

*CHI:	<one &+ss> [/] one play ground .
%wor:	one •321809_321969• play •322049_322310• ground •322390_322890• .
# &+ss is a fragment — excluded from %wor regardless of retrace context.

*EXP:	&+ih <the what> [/] what's letter &+th is this ?
%wor:	the •49103_49163• what •49183_50205• what's •50205_50405• letter •50405_50685• is •50946_51046• this •51086_51586• ?
# Fragments &+ih and &+th excluded; regular words remain.

*EXP:	what's is dis [: this] ?
%wor:	what's •37050_37471• is •37491_37631• dis •37631_38131• ?

*CHI:	xxx snack .
%wor:	snack •884668_885168• .
# xxx has no phoneme sequence — excluded from %wor; only snack appears.

*CHI:	&~um a boat .
%wor:	a •1073779_1073799• boat •1076861_1077361• .
# &~um is a nonword — excluded from %wor.

*CHI:	&-mm [<] bananas are good .
%wor:	mm •1949506_1949566• bananas •1949566_1949766• are •1949846_1949987• good •1950067_1950567• .
# &-mm is a filler — included in %wor (real spoken word with alignable phoneme sequence).

flowchart TD
    A["Main-tier word candidate"] --> B{"Timestamp token /\nomission / empty?"}
    B -->|Yes| OUT["Excluded from %wor"]
    B -->|No| C{"Untranscribed?\n(xxx/yyy/www)"}
    C -->|Yes| OUT
    C -->|No| D{"Fragment or nonword?\n(&+ or &~)"}
    D -->|Yes| OUT
    D -->|No| IN["Counts for %wor\n(word or filler &-)"]

    style IN fill:#afa,stroke:#333
    style OUT fill:#faa,stroke:#333

Phon Phonological Tiers

These tiers originate from the Phon project and provide syllable-annotated phonological transcription and segmental alignment. They were originally serialized as %x-prefixed user-defined tiers (%xmodsyl, %xphosyl, %xphoaln) and are being promoted to official CHAT tiers. Phon stores phonological data in its own XML format; the CHAT representation is generated by PhonTalk.

%modsyl / %phosyl — Syllabified Phonology

%modsyl is a syllabified version of %mod (target pronunciation); %phosyl is a syllabified version of %pho (actual pronunciation). Each phoneme is annotated with a syllable position code (N=nucleus, O=onset, C=coda, etc.). Words are space-separated and align 1-to-1 with the corresponding %mod or %pho tier.

*CHI:	the best .
%mod:	ðə bɛst .
%modsyl:	ð:Oə:N b:Oɛ:Ns:Ct:C .
%pho:	ðə bɛs .
%phosyl:	ð:Oə:N b:Oɛ:Ns:C .

Alignment: Content-based — stripping position codes (:N, :O, :C, etc.) and stress markers (ˈ, ˌ) from %modsyl should yield the same phonemes as %mod. Same for %phosyl → %pho.

%phoaln — Phone Alignment

%phoaln provides segmental alignment between target and actual IPA, showing phoneme-by-phoneme correspondence. Each pair uses source↔target notation; ∅ marks insertions or deletions.

*CHI:	the best .
%phoaln:	ð↔ð,ə↔ə b↔b,ɛ↔ɛ,s↔s,t↔∅

Alignment: Positional, word-by-word — word N in %phoaln aligns with word N in both %mod and %pho.

Parsing strategy: Same as %pho/%mod — we parse just enough structure for alignment (word boundaries for %modsyl/%phosyl, alignment pairs for %phoaln). IPA phoneme content is treated as opaque strings.

Validation (E725–E728)

Because these are derived views, word counts must match between each syllabification tier and its parent IPA tier:

These checks are gated on ParseHealth — if either tier in a pair has parse errors, the alignment check is suppressed to avoid false positives.

Known PhonTalk Export Issue

The PhonTalk XML→CHAT converter writes %mod/%pho through a OneToOne alignment path that maps IPA words to orthography words and silently drops extras. The syllabification tiers (%modsyl, %phosyl, %phoaln) bypass this path and include all IPA words. In child phonology data where children produce more IPA words than orthographic targets (~4% of Phon corpus files), this creates tier-to-tier word count mismatches. The mismatches originate in the Phon XML source data (orthography↔IPA word count discrepancies) and are inconsistently handled during CHAT export. This is being investigated in collaboration with the Phon team.

Bullet-Content Tiers

These tiers contain free-form text with optional embedded timing markers (•START_END•) and picture references (•%pic:"file.jpg"•). They do not align word-by-word with the main tier.

%cod remains bullet-content in the shared TalkBank AST, but current clan-core coding commands derive a semantic %cod item stream on top of that parsed content so selectors such as <w4> scope the following code instead of being counted as codes themselves.

Example with timing:

*CHI:	gimme that .
%act:	reaches toward shelf
%com:	child is pointing to picture

Text Tiers

These tiers contain plain text with no bullets, timing, or structural alignment:

User-Defined Tiers

Tiers prefixed with %x (e.g., %xcod, %xact) are user-defined dependent tiers. They are preserved during parsing and roundtrip but receive no structural validation beyond basic format checks.