kCura likes to use the term 'assisted review' for the Technology Assisted Review or predictive coding. It has a protocol posted to its site here, that it recommends be distributed to the reviewers actually making coding decisions.
The protocol warns users not to select documents as examples which don't use text even if they are very responsive. Relativity's assisted review technology uses Latent Semantic Indexing which is based on text - not individual keywords or phrases but concepts mainly conferred in complete paragraphs. Short documents are not considered good examples. The protocol specifically recommends reviewers against selecting spreadsheets with lots of numbers as these are not utilized in LSI either.
The system only makes decisions based on the bodies of email messages - not the headers which contain subject, date, author and recipient information, or footers with the standard disclaimers.
Oddly the protocol warns reviewers against select JPEG images of documents as responsive documents, since the system won't render the text in a searchable format. You would think that this would be a problem eliminated in the processing phase.
The protocol recommends using a 'Four Corners' test to determine if a document is a good example for the assisted review. One shouldn't selected documents as responsive examples on the basis of their relation to something else. A document isn't a good responsive example if you judge it to be so based on its being attached to a responsive document, its inclusion in a relevant date range, responsive network share, or key custodian's data set. So an email that attaches a responsive document should not be included in the training set.
If draft documents are subject to a carve out agreement, they should not be used even if they contain language that is otherwise responsive.
Coders are given two options to classify responsive documents, distinguishing between those that are good examples and those that are not.
Reviewers can make use of documents that only contain isolated passages of responsive text, by selecting text in the viewer, right clicking and choosing Assisted Review . . . Assisted Review add to Excerpt Text.