I just need to get a prolific distaste out of my mind...
Cogent comes from the Latin "co" meaning "with, together" and "agere" for "to drive". Crazy, I know. From "to drive together" of course, we get "convincing" and "relevant", but somewhere in between those two meanings, there was a detour through "forcing". I can see how driving together might be forcing, and then from there, "forcing" would arguably be "convincing", and by being convincing, it would arguably be "relevant".
So, cogent is used mostly with activities of people. Plaintiff's counsel could not make a cogent argument for his client's irrational demands. She gave cogent advice to her younger sister about how to impress her English teacher. She presented a cogent design for the layout of the furniture in the bedroom. Her son's cogent whining made her relent on her prohibition on ice cream. Not as good. Something about whining just isn't inherently persuasive as much as it is annoying, plus, since cogent is persuasive, it requires intent, not just sentience, and not just blunt repetition. My cat's cogent meowing reminded me to clean her litter. Maybe, if I elevate her meowing to talking to me and that she uses it rather effectively to motivate me. Similarly, computers do not generate cogent programs, but rather utilize such programs. So, I would stick to activities of people and only with people, unless you have a really smart pet.
I hope you find this entry cogent and useful!