Finally, TIMIT includes demographic data about the speakers, permitting fine-grained study of vocal, social, and gender characteristics.

Like the Brown Corpus, which displays a balanced selection of text genres and sources, TIMIT includes a balanced selection of dialects, speakers, and materials.

For each of eight dialect regions, 50 male and female speakers having a range of ages and educational backgrounds each read ten carefully chosen sentences.

Moreover, even at a given level there may be different labeling schemes or even disagreement amongst annotators, such that we want to represent multiple versions.

A second property of TIMIT is its balance across multiple dimensions of variation, for coverage of dialect regions and diphones.

Moreover, notice that all of the data types included in the TIMIT corpus fall into the two basic categories of lexicon and text, which we will discuss below.

Even the speaker demographics data is just another instance of the lexicon data type.These are organized into a tree structure, shown schematically in 1.2.At the top level there is a split between training and testing sets, which gives away its intended use for developing and evaluating statistical models.Structured collections of annotated linguistic data are essential in most areas of NLP, however, we still face many obstacles in using them.The goal of this chapter is to answer the following questions: Along the way, we will study the design of existing corpora, the typical workflow for creating a corpus, and the lifecycle of corpus.Two sentences, read by all speakers, were designed to bring out dialect variation: The remaining sentences were chosen to be phonetically rich, involving all phones (sounds) and a comprehensive range of diphones (phone bigrams).