This page explains why vendors do not agree with downloading all of the articles of a journal, defined as "systematic downloading" and affecting the market value of the work. After this explanation there are recommended search strategies to help analyze a large amount of text.
Systematic downloading refers to the prohibited method content is sometimes retrieved from a library database. There are multiple ways this can occur.
The market value of scholarly material is protected by a license. If an entire electronic journal volume is downloaded from a library to reuse multiple times, that means that the individual avoided purchasing said volume and the vendor is at an unanticipated loss. Vendors do not agree to downloading every article from a title unless text mining is expressly written into a license. In addition, the individual would not be in favor of the third factor of fair use (the amount being used) if they were to use/download the entire content from a journal (considered an individual copyrighted work).