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Encoders of text often find it useful to indicate that some aspects of the encoded text are problematic or uncertain, and to indicate who is responsible for various aspects of the markup of the electronic text. These Guidelines provide several methods of recording uncertainty about the text or its markup:
There are three methods of indicating responsibility for different aspects of the electronic text:
No special steps are needed to use the note and respStmt elements, since they are defined in the core module and header respectively. The alt element is only available when the module for linking has been selected, as described in chapter 17. Linking, Segmentation, and Alignment. To use the certainty, precision or respons elements, the module for certainty and responsibility should be selected.
These three elements are all members of an attribute class called att.scoping from which they inherit the following attributes:
| target | points at one or more sets of zero or more elements each. |
| match | supplies an XPath selection pattern using the syntax defined in Kay (ed.) (2017) which identifies a set of nodes, selected within the context identified by the target attribute if this is supplied, or within the context of the parent element if it is not. |
These attributes enable statements about certainty, precision, or responsibility to be made with respect to the whole of a document, or any part or parts of it which can be identified using standard XML location methods. Several examples are given in the discussion of the certainty element below; the same mechanisms are available for all three elements discussed in this chapter.
Many types of uncertainty may be distinguished. The certainty element is designed to encode the following sorts:
The following types of uncertainty are not indicated with the certainty element:
The advantage of this technique is its relative simplicity. Its disadvantage is that the nature and degree of uncertainty are not conveyed in any systematic way and thus are not susceptible to any sort of automatic processing.
To record uncertainty in a more structured way, susceptible of at least simple automatic processing, the certainty element may be used:
| locus | indicates more exactly the aspect concerning which certainty is being expressed: specifically, whether the markup is correctly located, whether the correct element or attribute name has been used, or whether the content of the element or attribute is correct, etc. |
| degree | indicates the degree of confidence assigned to the aspect of the markup named by the locus attribute. |
checked: my. This namespace prefix must be associated with an appropriate namespace definition, either on the certainty element itself, or on one of its ancestor elements.As noted in 17. Linking, Segmentation, and Alignment, the target attribute may take any general teidata.pointer as values and may thus also contain an XPath expression of arbitrary complexity. Because full support for XPath is not provided by current processors, it is not generally recommended TEI practice. There are however some simple cases in which XPath syntax is to be preferred, notably those in which the xml:id attribute is used to identify a single element occurrence. The usage #A (to indicate the element whose xml:id attribute has the value A) is syntactically much simpler than the equivalent xpath2 expression //*[@xml:id='A'] and is hence preferred throughout these guidelines.
For similar reasons, the certainty element may specify both a target value (expressed as an URI) and a match value (expressed as an XPath). The former defines the context within which the latter is to be evaluated. As previously noted, if no value is supplied for target, the context within which the value of match should be evaluated is the parent element of the certainty element itself.
The certainty element and the other TEI mechanisms for indicating uncertainty provide a range of methods of graduated complexity. Simple expressions of uncertainty may be made by using the note element. This is simple and convenient, and can accommodate either a discursive and unstructured indication of uncertainty, or a complex and structured but probably project-specific expression of uncertainty. In general, however, unless special steps are taken, the note element does not provide as much expressive power as the certainty element, and in cases where highly structured certainty information are needed, it is recommended that the certainty element be preferred.
As noted above, certainty about the accuracy of an encoding or its content is not the same thing as the precision with which a value is specified. In the case of a date or a quantity, for example, we might be certain that the value given is imprecise, or uncertain about whether or not the value given is correct. The latter possibility would be represented by the certainty element discussed in the previous section; the former by the precision element discussed in this section.
The elements concerning which statements of precision are to be made are identified using the same target and match attributes inherited from the att.scoping class discussed in the previous section and in the same way. Other aspects are provided by other attributes as further discussed below.
| precision | characterizes the precision of the element or attribute pointed to by the precision element. |
| stdDeviation | supplies a standard deviation associated with the value in question. |
Suppose however that the precision with which the value of such an attribute can be specified is variable. For example, suppose an event is dated ‘about fifty years after the death of Augustus’. In this case, the precision of one end of the range (the death of Augustus) is higher than the other, assuming we know when Augustus died. We can say that the latest possible date is probably 50 years after that, but with less confidence than we can attach to the earliest possible date.
In general, attribution of responsibility for the transcription and markup of an electronic text is made by respStmt elements within the header: specifically, within the title statement, the edition statement(s), and the revision history.
In some cases, however, more detailed element-by-element information may be desired. For example, an encoder may wish to distinguish between the individuals responsible for transcribing the content and those responsible for determining that a given word or phrase constitutes a proper noun. Where such fine-grained attribution of responsibility is required, the respons element can be used.
| locus | indicates the specific aspect of the encoding (markup or content) for which responsibility is being assigned. |
This element allows one or more aspects of the markup to be attributed to a given individual. This element inherits the target and match attributes from the att.scoping class, in the same way as the certainty and precision elements. Its locus attribute functions in the same way as that on the certainty element (see 22.1. Levels of Certainty). It inherits the resp and cert attributes from the att.global.responsibility class.
The module described in this chapter makes available the following additional elements:
The selection and combination of modules to form a TEI schema is described in 1.2. Defining a TEI Schema.