When someone reads an author's unfinished work, the author will get the most out of the reader's work if the author debriefs the reader. "How did you like it?" is not the kind of question the author should ask.
My first questions are meant to tell me if the reader understood the story. Why did Velma like Tara? Why did Tara leave home? What would have happened if Velma had found the magic ring that she was looking for? I ask these questions because (1) I need to know that the reader understood the story in order to judge whether the answers to the rest of the questions are meaningful and (2) I want to know if I wrote clearly.
After those first questions, I ask general questions. When were you bored during the story? When were you confused about something during the story? Where did you have to slow down or re-read?
Then come what are, for me, the most important questions. Did you want to know the answer to the mystery that Velma and Tara were trying to find? Was the answer obvious? Did it make sense? Did you like Velma? Why? Did you like Tara? Why not? Did you know where this scene took place? Why did it seem logical that Velma would think of Levin as someone who would not protect her? Did you think that Levin would protect Velma? Why? Did the scene where Velma was going down the stairs drag on too long? Did that scene seem necessary? Why? Was the magic in the story "believable?"
If the author has found the right reader and debriefed the reader properly, the writing can progress from good to great.