The “Bloom’s Dichotomous Key” or BDK was developed as part of the EOAS Flexible Learning project in Fall 2014 as a means of judging whether a task or test question causes students to engage in higher or lower order cognitive skills. It isn’t about “difficulty” because there can be difficult lower order (eg memory-based) tasks and easy synthesis or creative tasks.
This effort was based on work done by Casagrand and Semsar in the Dep’t of Integrative Physiology at U. of Colorado, Boulder, but we adapted it for use in geoscience, and based on repeated application by the TLF (Francis Jones) and a teaching assistant (Rhy McMillan).
This link provides a one-page flow chart for applying the key. It is “dichotomous” because Blooms level is arrived at by repeatedly considering yes/no questions about what students are being caused to do. The other two pages provide notes and guidelines plus a simplified flowchart figure. The tool is not officially published, but results have been employed as data for several presentations and workshops, both peer reviewed and not.
See the three-page PDF here: bdk-geoscience.