Constructive criticism, commonly abbreviated to concrit, is basically a useful review of a story, artwork, performance, etc. Here we're mostly concerned with writing.
Constructive criticism is one of the three basic forms of review, the other two being flames and worship. Flames can either be hurtful or amusing depending on the receiving author's mindset, and while worship is nice to get, it's not very helpful. Giving concrit is recommended whenever possible, because it can be very helpful indeed.
A review containing constructive criticism makes useful, specific comments about plot, characterization, or technicalities such as punctuation or spelling, either to point out problems (negative concrit) or to compliment excellent technique (positive concrit). Whether positive or negative, good concrit should tell the author specifically what was done well/poorly, and why, preferably with examples. If negative, it should also offer suggestions for improvement, either of the work in question or of future works. The less ambiguous it is, the more useful it will be to the author.
If possible, reviewers should try to find both positive and negative concrit for a story. (Emphasis on try—this may not always be possible.) This may include showing the author a way to use their strengths to lessen their weaknesses, or simply show the authors what to improve and what they're already good at. Reviewers should also have a good idea of the intent. For example, offer concrit on a trollfic's humor, because humor is the intent behind a trollfic.
Suggested Points of Concrit
If you want to give concrit but you're stuck for what to say, try picking one or two of the following points to start with:
- The plot
- The characters
- The action
- The dialogue
- The background
- The overall story
- The theme
- The technical details (spelling, grammar, canon details), etc.
"Concrit" is also the name of a building material used in HQ, possibly a pun on "concrete." As opposed to the smooth texture of Generic Surface, Concrit seems to be more brick-like. Actual concrit was also the jurisdiction of the former Department of Author Correspondence, which would contact badfic authors deemed salvagable and attempt to help them improve their writing.