In the following, we use the term automated text generation
[23] to refer to both template-based
and linguistically motivated generation methods.
Template-based generation methods require only a partial representation of the content to be conveyed. Furthermore, this method can be easily integrated into application programs; only little linguistic knowledge is required. On the other hand, as large portions of text are fixed within templates, the texts produced with this method tend to be monotonic and the activation of the same templates with different values for template variables results in repetitive sentences structures.
The large number of templates required for a flexible or multilingual realization of figure captions is a further disadvantage of the template-based generation method.
Linguistically motivated generation methods are appropriate for the
generation of flexible text, as these methods concentrate on the
generation of coherent and cohesive texts using a large variety of syntactic
structures. To establish cohesion in text appropriately, choices of
definite descriptions (pronouns, nominal groups) and the aggregation
of parallel structures are an important means. However, for these
methods a formal representation (domain knowledge, user models and a
representation of the context) and large linguistic resources
(grammars and lexica) are necessary which leads to a high initial
overhead with respect to the amount of work to be invested.