Of all the major skills needed for effective data processing, disk filing techniques are the most difficult to acquire.
The oddities of Apple DOS don't make it any easier, so this book looked as though it might be a welcome offering to the novice.
It's much more than the title suggests, being a complete tutorial on writing data-handling programs in Applesoft Basic rather than on disk-files alone.
It contains complete listings of several suites of programs, some of which look comprehensive. Each chapter introduces new concepts in Basic, with a question-and-answer section to check progress. But in the attempt to lead the novice gently, the author uses some quite appalling programming techniques.
The book, no doubt, contains useful information - but the poor technique obscures it.