Gordon Bateson's Essay (auto-grade) plugin allows the teacher to set some pre-defined target phrases. These target phrases are the 'important concepts' that the student should include in the essay.
I think that this plugin is best suited for formative assessments, where the teacher wants the student to really write a real essay, but the computer can quickly check whether the student has indeed written all the important concepts that the teacher expected the student to include.
With this plugin, the student can re-submit an essay that the computer marked (scored) as incomplete, until the essay has all the target phrases. Then it would be a good time for the human teacher to read the essay and approve the mark or highlight the grammar or conceptual errors in the essay.
The teacher can choose whether to show the target phrases that the student has met. That is very directed feedback.
Or the student can get a sub-optimal mark for the submitted essay, and the student must then think what important element the teacher expected to be included in the essay, that the student has not included yet. This would be my preferred style to use for University level essays, as too many of my students have little inclination to think carefully before answering a computer quiz (the result of too many multiple choice questions in many computer quizzes).
You can read my pathology question example with six target phrases in the plugin documentation. A few years ago, I used to make essay questions like this for paper-based (drill or for-real) exams, and the scoring guide had all the six target ideas that the student was expected to write, and each one was worth one point. Manually marking such assessments for 50 students every week was not much fun, but I can now have the computer check for these six important ideas automatically. Although I ought to check all the essays and substract points for grammar, spelling, wrong answers or lies in the essay.
I have not yet used this plugin for summative assessments, but I will write the results when I have them.