I'd also point out, mostly because I often do, that constructive critique isn't merely or even necessarily principally correction, the paradigm most of us bring with us from an early lifetime of attending schools. Nobody achieves excellence or prominence simply by eliminating negatives and focusing mostly on fixing where they fall short. In fact, particularly in my world of musical performance, but I believe in writing as well, the world forgives many stumbles or bad habits as long as there's a steady show of delightful traits. Excellence is not principally the absence of blemish. It is its own quality, without which the rest is for naught. Much as it might surprise anyone who reads or receives my critiques, I never go into a piece thinking "What can I find wrong with this?" or "What can I find to change?" I go in at least pretending to myself that I expect to find nothing to comment on. When a phrase or an observation kindles a spark of enthusiasm, I mark it. Because those are the moments that create and define good writing and notable writers. Encouragement isn't only about not discouraging writers, about keeping them in the game. It's more importantly about recognizing what makes them good, what may in time (or perhaps already) make them excellent, and making sure it's not accident or coincidence -- making sure they know it and develop it. Equally, and more often in most writing, when something sounds off -- a lapse in tone, a discordant element, a fumbled idiom, a non-intentional grammatical error, a missed opportunity -- I mark and often explain that as well. So I see nothing wrong with a purely positive critique, though I can't recall giving one. The closest was a piece of flash fiction in which I marked and gushed over many details and overall, yet pointed out that "oak" is a stronger, more iconic symbol than "oak tree," and highlighted a fumbled parallelism, and not much more. Finding fault with something faultless never improves it. It fosters a breeding ground for mediocrity and homogeneity. But I agree that superficial "good job, loved it, keep up the good work" doesn't add value. Positive or negative, people need to explain -- if not specifically why, then at least how it affected them as a reader, and which words, phrases, ironies, or other elements in particular.