Which type of document is recommended to be excluded from the Training Set data source?

The recommended type of document to exclude from the Training Set data source is Excel files with mostly numbers. This is because training data typically needs to contain textual information that can be analyzed and understood in the context of the project. Documents that primarily consist of numerical data do not provide the qualitative insights that textual documents can. Training sets are usually designed to enhance understanding of language patterns, terminology, and semantics, which are better represented in textual formats like Word documents, reports, and presentations, as they include narratives or descriptions that can be valuable for training purposes.

While reports with diagrams, Word documents, and presentations all contain elements that can support training and understanding, Excel files focusing primarily on numerical data may not contribute effectively to the training objectives, which include discerning language use, context, and communication strategies. Therefore, excluding such files helps maintain the quality and focus of the training set data.