All of the above are forms of feedback. The first two positive, and the latter negative... but none of them were constructive feedback. Why did they love it? Why was it good? Why did it suck? From what those readers wrote, I really got no idea of what moved them, good or bad.
'Constructive' feedback consists of identifying those items that stood out from the story, good or bad, and relating them to the author in a way that they know why it made you feel the way it did. Why did it move you? Why did it make you excited, angry, happy, upset, delighted, disgusted or horny?
'Constructive' feedback also provides the author with your comments in a manner designed to identify strengths or shortcomings in such a way that not offensive or emotional. It sticks to the facts of the story without attacking the author. This is especially important when identifying things you consider to be shortcomings in a story.
When I read something like - "Your story sucked, asswipe! Why do you write such crap?" I personally tend to just toss it in the trash with the remainder unread. That's the common response most people have when they feel attacked by someone – an immediate defensive reaction is to stop paying attention to what the writer is saying and fight back, or defend yourself.
When I read something like - "The main characters in your story lacked any depth and I couldn't really relate to them. That kept me from getting into your story." - or - "The way you kept switching between past and present tense in your story really made it hard to follow." I get a much clearer picture of what a reader didn't like in a story and it's presented in a manner that doesn't immediately make me react defensively. It makes me go back and look at my story and see where I made those mistakes, or think of ways to strength my writing style to make my stories more enjoyable to the readers. Those are examples of negative reactions presented in a constructive manner, to help an author become a better writer.
Positive feedback with specific instances of what moved you help reinforce good things in an author's style. Examples of some positive constructive feedback are: "I liked the way you build up the suspense." "I knew exactly how the woman in your story felt because of your vivid imagery in describing her thoughts." "I liked the way you used rich descriptive phrases in your story to show me what was going on." All three examples pointed out specific things that the reader enjoyed and made the story a better experience for them. That tells me what I am doing right! It's important for me as an author to know what my readers enjoy most as well, so I can continue to include that in my stories, or work to make that even richer for my readers.
