On writing reviews...
We've all seen them on Amazon. The one line reviews that say "This book sucked!" or "This book is great!". They're not very helpful, and one of the reasons they're not very helpful is that they don't tell you _why_ the book sucked or was great. You have no way of knowing whether that person's tastes match yours, and hence whether you can trust their opinion to reflect what you'd think of the book.
The job of the reviewer isn't to say whether she liked or disliked the book--or indeed to say whether the book was good or bad, for it is quite possible to like a bad book and dislike a good book. Ideally, what the reviewer should be doing is providing information that helps other people to decide whether or not a book would be of interest to them. That the reviewer liked/disliked the book is important, but the reason _why_ is more important. If I read a review by someone who disliked a book, but who takes the time to explain what she disliked about it, I may well find that her reasons would be good reasons for me to buy it, and vice versa. We may simply have different tastes; or the book may target a specific audience and be of no interest to those outside that audience. A good reviewer recognises those possibilities, instead of assuming that everyone is looking for the same things in a book.
I have a very specific example in mind. A few days ago as I write this, I was wondering whether it would be worth buying an updated version of an O'Reilly manual. (For those who don't know, O'Reilly publish a much-respected line of IT technical reference books.) The one I'm using is the 1998 edition, and as such dates from the Stone Age in computer terms. It's still useable, but I thought that I should look at whether it was worth buying a newer edition.
It turned out that there were not one but two books that I might want to look at, so I settled down to read the reviews. It rapidly became clear that the technical people didn't think much of one of the books. Too basic, too much repetition of things that were obvious, the author hadn't written the book that they wanted. Most of them were content to slam the book as unworthy of the O'Reilly name. Most of them saw it only as a book that had failed practicing geeks.
The beginners, on the other hand, loved the book. It was pitched to their level, and they appreciated it. That was fine, because that was the sort of book I was looking for. But because they were beginners, I couldn't trust their judgement of whether the book was technically accurate.
And then there were a couple of technical guys who said very bluntly that the book was a failure as far as they were concerned --but who also recognised that ubergeeks were not the only potential audience for the book. _Those_ guys took the trouble to explain why they thought the usual audience for O'Reilly books would find the book a poor buy, while at the same time it was probably a very good book for people who were just starting. They felt that it was at a very basic level and very repetitious, but it was clearly written, accurate and reliable in what it did cover. It was a beginner's tutorial rather than a reference guide, and it did it very well. And they said this without being condescending to people at a basic level.
Those are the reviews that got a "helpful" rating from me. They gave me the information that enabled me to decide whether the book would be useful to _me_, instead of assuming that if they didn't like it, nobody should.
I formed my review-writing habits back in my fanfiction days. I got into fanfiction in the days before net access was that widespread, and I was in an old fandom where most of the existing fiction was in printzines, and wasn't ever going to get online unless someone sat there with a scanner for hours on end. That meant that if you wanted to read it, you had to buy it mail order sight unseen, or at a con where you might not be able to do more than flip quickly through it to get a rough feel for the contents. And zines weren't cheap. So I was very grateful for the advice I received from other fans as to what to buy. That advice didn't just cover the intrinsic quality of the writing, but whether the zine was likely to be to my taste. In return, when I started writing reviews of the zines I bought, I did so with the intention not just of saying whether _I_ liked the zine, but whether I thought other people would like it. I wanted to provide other fans with the information they needed to decide whether to buy a zine, and how much they might be willing to pay to get it, whether or not their tastes were the same as mine. Was it well written? Did it press common pro- or anti- buttons that would make people seek it out or avoid it regardless of quality? Did it have serious spoiler issues? Did it have a lot of coverage of a character who didn't normally get much attention, and thus appeal to fans of that character?
I don't have to _like_ a story to be able to say that it is a well written or badly written story. There were a number of writers in the fandom who were well known for bashing characters they didn't like. I'm unlikely to like a story that bashes my favourite character, but I can still tell whether it was written by someone who knows how to construct a story, or by someone who demonstrates the truth of Sturgeon's Law. And I may not like it, but if it's well written there will be people who _will_ like it, because they don't mind seeing that character bashed. On the other hand, they probably won't want to read it if it's simply a bad story. So they'll want to know--did I dislike it because I wouldn't have liked it no matter how well it was written, or did I dislike it because it was badly written rubbish? A simple "this story sucked" isn't very helpful to them even if they know my tastes, while a more detailed "I did not like this story because..., but it is well-written and I think people who don't mind or like.... will probably enjoy it" gives them a chance to judge whether they might like it even if I didn't.
There's a similar thing for stories that I liked because they happened to hit my buttons, but that I realise are flawed in their execution. People who share my tastes will probably also enjoy them anyway, while others might take or leave such a story.
And I kept any issues I had with the authors or editors out of it. If I couldn't write an unbiased review, I didn't write a review. There were a couple of occasions when I could have written an unbiased negative review, but it might have looked as if I was motivated by spite--and I did not publish those reviews at the time, but waited until much later. That doesn't mean you can't write a review when you're biased, but you must be honest with yourself and your readers that you're biased, whether it's a positive or a negative bias.
I continued in that vein when reviewing commercial material likely to be of interest to my fellow fans--who did I think this was likely to appeal to, was there anyone likely to find it a waste of money no matter how good it was, was there anyone who might enjoy it but should put it off until after they had read or watched or listened to other material?
And I find now that I apply this to general reviews, even to considering whether a book in a series will be accessible to readers who haven't read the earlier books, or contains spoilers for those earlier books. And I wish more people would do the same.
These are some of the things I think about when I sit down to write a review:-
Did I enjoy the book? (Or did I find it useful?)
If I did enjoy it, was it in spite of obvious flaws? Will those flaws bother other people?
If I didn't enjoy it, was it because I wouldn't have enjoyed it no matter how well it was written? If that's the case, do I think that other people with different tastes might enjoy it?
Is it so badly written that nobody's going to like it? (In which case I probably didn't finish it, and unless it's _really_ annoyed me, I'm probably not going to bother spending the time to write a review. Life's too short.)
Does it stand alone, or do you need to read something else first?
I'm not going to write a long, detailed review of everything. I'm not spending a huge amount of time on writing reviews for Amazon when Amazon takes a licence to sell those reviews on to others, with no compensation in return, and on my own blog I may well say in passing, "I've just read such-and-such and it was brilliant!" But I do try to provide a little bit of detail beyond "It was good/bad." It's more helpful to other people. And I know that if I want to influence people to read/avoid a book, I'm more likely to succeed if I provide them with solid reasons for doing so. After all, why should I expect others to pay attention to the sort of single-sentence review that I routinely ignore?