At some point in the editing stages of any writing project it is extremely helpful to have another person read the work and give feedback, preferably in the form of constructive criticism. While the final draft and any changes made are ultimately the decision of the author, having other eyes on the piece often reveals where work actually needs to be done. Authors overlook all kinds of faults, major and minor, in what they write because they can see the vision in their head. The problem is in translating this vision so readers can catch a glimpse of it too. When plot holes get left unfilled or description is severely lacking, it's a frustration to the reader.
This is where beta readers come in. Beta readers give the feedback and suggestions which can take a mediocre second (or third or fourth) draft (I would never give anyone a first draft to read) and help the author turn it into an amazing published book.
In order to do so, beta readers need to be able to give constructive criticism because neither saying "Oh, it's good. I loved it" or tearing the whole thing to shreds is helpful to the author. A good beta reader will note both good and bad points of the story/setting/characters, be able to point out anything they found confusing, and generally pass along suggestions for improvement.
This is where beta readers come in. Beta readers give the feedback and suggestions which can take a mediocre second (or third or fourth) draft (I would never give anyone a first draft to read) and help the author turn it into an amazing published book.
In order to do so, beta readers need to be able to give constructive criticism because neither saying "Oh, it's good. I loved it" or tearing the whole thing to shreds is helpful to the author. A good beta reader will note both good and bad points of the story/setting/characters, be able to point out anything they found confusing, and generally pass along suggestions for improvement.