Funny video spoof on the ever so hilarious "What Does the Fox Say" song.  

Principles for ethical standards...........written in 2010    Here is the document:    http://www.nasponline.org/standards/2010standards/1_%20Ethical%20Principles.pdf

The APA is offering a number of “emerging measures” for further research and clinical evaluation. These patient assessment measures were developed to be administered at the initial patient interview and to monitor treatment progress. They should be used in research and evaluation as potentially useful tools to enhance clinical decision-making and not as the sole basis for making a clinical diagnosis. Instructions, scoring information, and interpretation guidelines are provided; further background information can be found in DSM-5. The APA requests that clinicians and researchers provide further data on the instruments’ usefulness in characterizing patient status and improving patient care at http://www.dsm5.org/Pages/Feedback-Form.aspx.
Measure:

"

The "but you are free to accept or to refuse" technique is a
compliance procedure in which someone is approached with a
request by simply telling him/her that he/she is free to accept or to
refuse the request. This semantic evocation leads to increase
compliance with the request. Furthermore, in most of the studies
in which this technique was tested, subjects have been asked to
give money to a confederate. A new evaluation of the effect of this
technique was tested in an experiment in which subjects in the
street have been approached to respond to a survey. The results
show that, when the semantic evocation of freedom is included in
the request, a higher compliance rate occurred. The commitment
theory was used to explain such results"

Translation?  If we give students choices; if we let them know particiaption is voluntary - participation/motivation/engagement is likely to increase.