P5: Guidelines for Electronic Text Encoding and Interchange

TEI: Linguistic Segment Categories¶17.1 Linguistic Segment Categories

In this section we introduce specialized linguistic segment category elements which may be used to represent the segmentation of a text into the traditional linguistic categories of sentence, clause, phrase, word, morpheme, characters, and punctuation marks.

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TEI: Below the Word Level¶17.1.2 Below the Word Level

It is sometimes helpful to markup explicitly sub-word components such as morphemes, characters, or punctuation.

• m (morpheme) represents a grammatical morpheme.
• c (character) represents a character.
• pc (punctuation character) contains a character or string of characters regarded as constituting a single punctuation mark.

The m element is used to mark up morphologically identified segmentation below the word level. Analogous to the lemma attribute for w, there is a baseForm attribute for the m element, which may be used to indicate the ‘base form’ of an inflected morpheme; where appropriate, m elements may also be organized hierarchically:

<w type="adjective">
 <m type="base">
  <m type="prefix" baseForm="con">com</m>
  <m type="root">fort</m>
 </m>
 <m type="suffix">able</m>
</w>

The distinction between m and w is provided as a convenience only; it may not be appropriate for all linguistic theories, nor is it meaningful in all languages. The intention is to provide a means for those cases where it is considered helpful to distinguish lexical from sub-lexical tokens, to complement the more general mechanism already provided by the seg element, using which the above example could alternatively be marked up as follows:

<seg type="adjective">
 <seg type="base">
  <seg type="prefix">com</seg>
  <seg type="morph">fort</seg>
 </seg>
 <seg type="suffix">able</seg>
</seg>

There is a substantial linguistic difference between characters like letters or diacritics and punctuation marks. The former are used to construct meaningful units like morphemes or words. The latter are functionally independent units acting at the level of syntactic units. A word may consist of a single letter (for example ‘I’ in English), but this does not mean that we should use c instead of w to mark it up.

The c (character) element should be used to mark up any non-lexical character, whether this appears within a word, or outside it. In the following example, the encoder wishes to indicate that the letters are not to be regarded as words:

<phr>
 <c>M</c>
 <c>O</c>
 <c>A</c>
 <c>I</c>
 <w>doth</w>
 <w>sway</w>
 <w>my</w>
 <w>life</w>
</phr>

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The c element may be used for individual characters occurring within a w or m element which it is desired to distinguish for some reason, as in the following examples:

<m baseForm="not">
 <c>n</c>
 <c type="punct">'</c>
 <c>t</c>
</m>

This encoding represents the constituents of a common abbreviation, but does not indicate that it is in fact an abbreviation; the am element (11.3.1.2 Abbreviation and Expansion) may be preferred for the latter purpose. Generally speaking, the use of c use to mark non-lexical punctuation marks is deprecated, since the pc element is provided specifically to distinguish these.

The pc (punctuation character) element should be used to mark up characters which are specifically regarded as providing punctuation, rather than constituting parts of a word. It may be particularly useful when transcribing older written materials, in which an encoding of the original punctuation may be useful for interpretive or analytic purposes, in much the same way as an encoding of the original orthography may be. For example, in the following extract from a Bodleian Library musical manuscript

two different punctuation marks are used to distinguish kinds of pause in the text. The punctus elevatus (which resembles an inverted semicolon) is not a Unicode character, but may still be encoded using the g element. As further described in chapter 5 Characters, Glyphs, and Writing Modes, this element points to a definition for the intended character which may be stored either locally or elsewhere.

deus qui regis omnia
<pc>
 <g ref="#pelev">;</g>
</pc> natus est in bethlehem
<pc>.</pc>o <pc>.</pc> mira gratia...

<!-- elsewhere -->
<char xml:id="pelev">
<!-- definition of the punctus elevatus character -->
</char>

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The pc element carries special attributes to record analyses of the functional behaviour or classification of the punctuation mark it contains. The unit attribute may be used, as on the milestone element to name the kind of unit which the punctuation mark delimits, for example a paragraph or section. The pre attribute may be used to indicate whether the punctuation precedes or follows the unit it delimits. The force attribute indicates the strength of the association between the punctuation mark and its adjacent word.

In the following example, the paragraph marker (¶) has been tagged as a strong punctuation mark, preceding the unit it marks, which is named ‘para’:

<p>
 <pc unit="para" force="strong" pre="true">¶</pc>Incipit...
</p>

The w, m, c, and pc elements can be used together to give a fairly detailed low-level grammatical analysis of text. For example, consider the following segmentation of the English S-unit I didn't do it.

<w>I</w>
<w>
 <m baseForm="do">did</m>
 <m>n't</m>
</w>
<w lemma="do">do</w>
<w>it</w>
<pc>.</pc>

This segmentation, crude as it is, succeeds in representing the idea that did occurring as a morphological component of the word didn't has something in common with the word <do>. A further advantage of segmenting the text down to this level is that it becomes relatively simple to associate each such segment with a more detailed formal analysis, for example by providing a baseform, or morphological analysis at whichever level is appropriate. This matter is taken up in detail in section 17.4 Linguistic Annotation.

TEI: Global Attributes for Simple Analyses¶17.2 Global Attributes for Simple Analyses

When the module described by this chapter is selected, an additional attribute is defined for all elements:

• att.global.analytic provides additional global attributes for associating specific analyses or interpretations with appropriate portions of a text.

  ana	(analysis) indicates one or more elements containing interpretations of the element on which the ana attribute appears.

The ana attribute may be specified for any element. Its effect is to associate the element with one or more others representing an analysis or interpretation of it. Its target should be one of the elements described in the section 17.3 Spans and Interpretations below, or some other interpretative element such as note, on which see section 3.8 Notes, Annotation, and Indexing or fs, on which see chapter 18 Feature Structures.

TEI: Spans and Interpretations¶17.3 Spans and Interpretations

The simplest mechanisms for attaching analytic notes in some structured vocabulary to particular passages of text are provided by the span and interp elements, and their associated grouping elements spanGrp and interpGrp.

• span associates an interpretative annotation directly with a span of text.
• spanGrp (span group) collects together span tags.
• interp (interpretation) summarizes a specific interpretative annotation which can be linked to a span of text.
• interpGrp (interpretation group) collects together a set of related interpretations which share responsibility or type.

These elements are all members of the class att.interpLike, and thus share the following attributes:

• att.interpLike provides attributes for elements which represent a formal analysis or interpretation.

  type	indicates what kind of phenomenon is being noted in the passage. Sample values include: 1] image; 2] character; 3] theme; 4] allusion
  inst	(instances) points to instances of the analysis or interpretation represented by the current element.

• att.responsibility provides attributes indicating who is responsible for something asserted by the markup and the degree of certainty associated with it.

  cert	(certainty) signifies the degree of certainty associated with the intervention or interpretation.
  resp	(responsible party) indicates the agency responsible for the intervention or interpretation, for example an editor or transcriber.

The type attribute of the span and interp elements may be used to indicate that the annotations are of specific types, for example thematic or structural. The annotation itself is supplied as the content of the span or interp element. In the case of the span element, the span of text being annotated is indicated by values of the from, to or target attributes, used in combination as follows. If only the from attribute is supplied, then the span is coterminous with the element indicated by its value; if both from and to are supplied, the span runs from the start of the element indicated by the from attribute up to the end of the element indicated by the to attribute; if the target attribute is used, the span is defined by aggregating the contents of the (possibly non-contiguous) elements pointed to by its values. It is an error to supply only the to attribute; to supply more than one pointer value for either to or from attributes; or to supply either of these in conjunction with the target attribute. In the case of interp (see below), the span is indicated by a pointer from a link element or some similar mechanism. The resp attribute indicates the annotator responsible for this annotation.

Spans may also be used to represent structural divisions within a narrative, particularly when these do not coincide with the structure implied by the element structure. Consider the following narrative:

Note the use of an empty anchor element to provide a target for the ‘reconciliation’ unit which is normally part of the narrative pattern but which is not realized in the text shown.

The same analysis may be expressed with the interp element instead of the span element; this element provide attributes for recording an interpretive category and its value, as well as the identity of the interpreter, but does not itself indicate which passage of text is being interpreted; the same interpretive structures can thus be associated with many passages of the text. The association between text passages and interp elements must be made either by pointing from the text to the interp element with the ana attribute defined in section 17.2 Global Attributes for Simple Analyses, or by pointing at both text and interpretation from a link element, as described in chapter 16 Linking, Segmentation, and Alignment.

One obvious advantage of using interp rather than span elements for the Sigmund text is that the interp elements can be reused for marking up other texts in the same document, whereas the span elements cannot. On the other hand, the use of interp elements may require the creation of special text elements not otherwise needed (e.g. the seg and the join in the revised encoding of the text), whereas the use of span elements does not.

TEI: Linguistic Annotation¶17.4 Linguistic Annotation

By linguistic annotation we mean here any annotation determined by an analysis of linguistic features of the text, excluding as borderline cases both the formal structural properties of the text (e.g. its division into chapters or paragraphs) and descriptive information about its context (the circumstances of its production, its genre or medium). The structural properties of any TEI-conformant text should be represented using the structural elements discussed elsewhere in this chapter and in chapters 3 Elements Available in All TEI Documents, 4 Default Text Structure, and the various chapters of Part III. The contextual properties of a TEI text are fully documented in the TEI header, which is discussed in chapter 2 The TEI Header, and in section 15.2 Contextual Information.

Other forms of linguistic annotation may be applied at a number of levels in a text. A code (such as a word-class or part-of-speech code) may be associated with each word or token, or with groups of such tokens, which may be continuous, discontinuous, or nested. A code may also be associated with relationships (such as cohesion) perceived as existing between distinct parts of a text. The codes themselves may stand for discrete and non-decomposable categories, or they may represent highly articulated bundles of textual features. Their function may be to place the annotated part of the text somewhere within a narrowly linguistic or discoursal domain of analysis, or within a more general semantic field, or any combination drawn from these and other domains.

The manner by which such annotations are generated and attached to the text may be entirely automatic, entirely manual or a mixture. The ease and accuracy with which analysis may be automated may vary with the level at which the annotation is attached. The method employed should be documented in the interpretation element within the encoding description of the TEI header, as described in section 2.3.3 The Editorial Practices Declaration. Where different parts of a language corpus have used different annotation methods, the decls attribute may be used to indicate the fact, as further discussed in section 15.3 Associating Contextual Information with a Text.

As one example of such types of analysis, consider the following sentence, taken from the Lancaster/IBM Treebank Project (Leech and Garside (1991)).

Our discussion focuses on the way that this sentence might be analysed using the CLAWS system developed at the University of Lancaster but exactly the same principles may be applied to a wide variety of other systems.⁷² Output from the system consists of a segmented and tokenized version of the text, in which word class codes have been associated with each token. CLAWS offers outputs in a variety of non-XML and XML formats: for example, the simplest format for the sample sentence would be:

The_AT0 victim_NN1 's_POS friends_NN2 told_VVD police_NN2 that_CJT Kruger_NP0 
drove_VVD into_PRP the_AT0 quarry_NN1 and_CJC never_AV0 surfaced_VVD

This approach requires the text to be fully segmented, using the linguistic segment elements described in section 17.1 Linguistic Segment Categories, so that the scope of the ana attribute used to point to each interpretation is clearly defined. A further analysis into phrase and clause elements can be superimposed on the word and morpheme tagging in the preceding illustration. For example, CLAWS provides the following constituent analysis of the sample sentence (the word class codes have been deleted):

[N [G The victim's G] friends N] [V told [N police N] [Fn that 
[N Krueger N] [V [V& drove [P into [N the quarry N]P]V&] and 
[V+ never surfaced V+]V]Fn]V]

Each linguistic segment so far discussed has been well-behaved with respect to the basic document hierarchy, having only a single parent. Moreover, the segmentation has been complete, in that each part of the text is accounted for by some segment at each level of analysis, without discontinuities or overlap. This state of affairs does not of course apply in all types of analysis, and these Guidelines provide a number of mechanisms to support the representation of discontinuities or multiple analyses. A brief overview of these facilities is provided in chapter 20 Non-hierarchical Structures; also see 16 Linking, Segmentation, and Alignment. These mechanisms all depend to a greater or lesser degree on the use of pointing elements of various kinds.