From the abstract:
This study constitutes an update of its predecessor released last year. The silken thread, being drawn a second time, this new document should be reviewed in relation to its 2018 first edition. Releasing any successor version recommends dual explanation: what has not changed and what has changed. The former far outnumbers the latter. First among matters not changed is study objective. Institutions still must make data base acquisition decisions – and need to know what they are buying. Vendors build these systems – and need feedback enabling improvements. These considerations recommend a method for objective evaluation. The present effort aims at offering one such method.
Study method has not changed, except in one detail. This time, six legal databases are addressed: CASEMAKER, FASTCASE, LEXIS, WESTLAW, GOOGLE SCHOLAR, and BLOOMBERG LAW. The approach remains a combination of inductive and deductive logic. Induction operates from the “back forty” wherein six topics embedding similar questions are run through these systems. Deduction operates from the “front forty” wherein data, empirically derived, draws back into general overview.