How many editions of a book have been published?

I asked my friend Steve Loyola to help out with this one. Steve runs Best Book Buys.com and spends much of his day munging around in the miasma that is publication and book data. Here’s his useful response:
When all else fails, I head to the Library of Congress Catalog website: They have a Basic Search that lets you search on only one field, and a Guided Search that lets you search on more than one field at a time. The Guided Search will help us more with this question. On the Guided Search page, I entered “Perspective Drawing” in the first search field, changed “all of these” to “as a phrase”, and changed the “As” field to “Title: All (KTIL)”. On the second line, I entered “James, Jane” and changed the “As” to “Name: Personal Name (KPNC)”:

Clicking “Begin Search” shows us two entries: “Perspective drawing : a directed study” (1981) and “Perspective drawing: a point of view” (1988). At first these look like they could be two completely different books, but clicking on the second title reveals more details, including the fact that this is a 2nd edition. I’m not 100% sure but I suspect that the 1988 book is the second edition of the 1981 book.
Finally, regarding signs that there might be a 1980 edition (as shown on sites like Amazon.com and BestWebBuys.com), I believe this is simply a data inconsistency problem. I think those 1980 editions are really the 1981 edition. Sometimes book details are not perfect. It may be that this book was originally planned to be published in 1980 but wasn’t actually released until 1981. If there were separate 1980 and 1981 editions, they would have different ISBNs.
You can find price comparisons for both books here:
• Perspective Drawing: A Directed Study (1981)
• Perspective Drawing: A Point of View (2nd edition) (1988)