I have nothing at hand, but learning/task engagement is a concept which also is part of the cognitive load theory (Chandler & Sweller), and 'germane load' measures are very closely related to your question. I would be surprised when nothing can be found , when searching in this direction.
Hi René and Klemens, thanks so much for your responses.
I'm more interested in one scale capable of to measure the engagement in terms of psychological assessments, for instance, like the flow state scales (Kawabata, M., Mallett, C. J., & Jackson, S. A. (2008). The flow state scale-2 and dispositional flow scale-2: Examination of factorial validity and reliability for Japanese adults. Psychology of Sport and Exercise, 9(4), 465-485).
If you know something about this kind of scale to measure engagement, please, answer this question.
Measuring student engagement in virtual environment follows slightly different indicators than the measure of engagement in a face-to-face learning environment. This reference is appropriate to capture the gist of the matter.
Hullinger, H., & Robinson, C. C. (2008). New Benchmarks in Higher Education: Student Engagement in Online Learning. Journal of Education for Business, 84(2), 101-109.
Also, this reference is important to see engagement in a comparative perspective.
Rabe-Hemp, C., Woollen, S., & Humiston, G. S. (2009). A Comparative Analysis of Student Engagement, Learning, and Satisfaction in Lecture Hall and Online Learning Settings. Quarterly Review of Distance Education, 10(2), 207-218.