A good therapy dog candidate is one that is laid back, feels relaxed around new people — adults and kids alike — and that can achieve a fairly rigorous level of training. (doorcountyhumanesociety.org)
Because moving to a more rigorous level improved my son's math skills. (educationnext.org)
On the one hand, if content and performance standards are set at a very rigorous level for all students, many will inevitably fail. (educationnext.org)