Dependent Tiers

Status: Reference Last updated: 2026-10-20 (commit f7e32e22)

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

Chatter represents dependent tiers in four broad structural categories:

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 typed representations, but they do not share one universal word count. %mor uses morphosyntactic units; %gra uses MOR chunks, including clitics and a terminator chunk when present. %pho, %mod and %sin use their own positional domains, which handle pauses, groups and retraces differently. %wor is a separate timing sidecar, not a structural count-validity check. See the alignment rules for domain-specific membership and terminator handling.

%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|NSUBJ 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). Two of those describe the tier AS A WHOLE and are withheld when the tier in hand is not the one you wrote: E721 and E722, when the parser had to reject a relation it could not represent, or when %mor-to-%gra alignment has already reported a count or index fault. E723 and E724 are always reported, because dropping a relation cannot create a second root or close a cycle, so a violation among the relations that survive is one the transcript contains.

%pho / %mod, Phonological Transcription

The %pho tier records actual pronunciation; %mod records target/model pronunciation. Both align to Pho-domain units on the main tier. Simple word sequences align word by word, but pauses and phonological groups also affect the unit inventory; this is not a count of whitespace-separated words alone.

*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. Timing data comes from the bullet fields. Word text is not lexical authority, but consumers may compare it with chatter’s canonical generated display sequence to refuse stale same-count timing reuse.

⚠ IMPORTANT: %wor word text is the cleaned form, by design. When chatter serializes a %wor word it writes the word’s cleaned text, the spoken form with surface markers removed, NOT the raw main-tier surface form. This is a deliberate convention (see WorTier::write_chat in crates/talkbank-model/src/model/dependent_tier/wor.rs), chosen for human readability and because %wor exists to anchor timing, not to re-state the main tier’s orthography. The generated %wor text and the TextGrid export both use this cleaned form.

Consequence you must know: surface markers carried on a word, prosodic lengthening (wabe:), and similar in-word notation, are not preserved in %wor output. A main-tier word wabe: becomes wabe on %wor. This means a %wor line containing such words does not byte-roundtrip (parse, serialize, reparse changes the surface text), and that is expected, not a bug. %wor is a cleaned, timing-only view; the main tier remains the faithful record of surface forms. Do not “fix” the %wor serializer to emit raw text without an explicit decision to change this convention.

%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.
• Fragments (&+...) do NOT count under the current policy.
• Nonwords (&~...) do NOT count under the current policy.
• Untranscribed placeholders (xxx, yyy, www) do NOT count.
• 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.

These are the named FilteredLexicalV1 membership rules, not empirical proof of what every acoustic aligner can or cannot time. Inclusion does not establish a known pronunciation or accurate interval. The timing contract owns the policy and its checked consumer transitions.

%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. CHAT validation does not require the %wor count to match the current main tier. Timing consumers first require equal counts and then require every %wor display token to match the canonical token derived from its main-tier position. A mismatch refuses timing reuse without making the legacy CHAT file invalid.

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

For example, <one &+ss> [/] one play ground contributes two distinct one slots, then play and ground: the retraced word remains, while the fragment does not. gonna [: going to] contributes the original gonna slot, not two replacement slots. These are membership examples, not measured timing intervals. Equal counts or matching display text do not prove acoustic accuracy or immutable common origin.

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. Chatter accepts both unprefixed names and %x-prefixed aliases (%xmodsyl, %xphosyl, %xphoaln, %xphoint), and serializes the prefixed form. See Phon Tiers for interval syntax and the complete validation contract; input aliases do not certify any exporter’s output.

%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.) from %modsyl must reproduce the corresponding %mod word exactly, including stress markers (ˈ, ˌ). The same applies to %phosyl → %pho. Pause fillers must reproduce the same pause token rather than phone:CODE units.

%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: Word-by-word, with independent source positions. A one-sided pause such as (..)↔∅ consumes a %mod slot but no %pho slot; ∅↔(..) does the reverse. Other alignment words consume both source slots, including ordinary non-pause insertions and deletions.

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.

Count diagnostics establish a mismatch in the supplied CHAT, not its cause. See Interpreting mismatches before changing a transcription or attributing a discrepancy to an exporter.

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 is bullet-content in the shared TalkBank AST. In the %cod coding convention, a word selector such as <w4> scopes the code that follows it (it names which main-tier word the code applies to) rather than being a code in its own right.

Example without optional 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 the extension point for project-specific annotation. Their content does not acquire the structural alignment contract of a standard tier merely by resembling its name. The extension is still subject to parsing and applicable format checks; a %x prefix is not a blanket guarantee that malformed input will be accepted.

The Supported Set Is Closed

Chatter recognizes the standard tier set and the %x user-defined extension. An unsupported dependent-tier name is reported as E605 (UnsupportedDependentTier), not merely a warning. Recognition is necessary, not sufficient: a recognized tier can still contain invalid syntax or violate its domain’s rules. The implementation enforces the supported contract; its output alone does not settle a disputed format rule or prove a data defect.

Deliberate Divergence from CLAN: Retired Legacy Tiers

When TalkBank standardized morphology on a single Universal Dependencies %mor tier (plus %gra for relations), several legacy dependent tiers were retired. CLAN’s check still accepts three of them, so on these chatter is intentionally stricter, a deliberate, documented divergence:

The modern UD-%mor workflow has one morphology tier (%mor) plus %gra; the older training/translation/variant tiers are no longer part of the format chatter validates. %umor is rejected by both validators and is listed only for completeness. Note that %xtra (with the %x prefix) is a perfectly valid user-defined tier; only the bare %tra is retired.

This is one instance of a general principle: where chatter intentionally departs from CLAN/CHECK behavior, the divergence is documented rather than left implicit. See CHECK Parity Audit.

This page last changed: 2026-10-20 (commit f7e32e22). The whole book last changed: 2026-10-27 (commit 5bfee2f9).