- Indicating the need for abstract theory even in applications and showing the inadequacy of existing results for certain apparently simple real-world problems
- Attempting to deal with the existence problems for various classes of random families that figure in the main results of the subject
- Providing a treatment of conditional expectations and of conditional probabilities that is more complete than in other existing textbooks
Since this is a textbook, essentially all proofs are given in complete detail (even at the risk of repetition), and some key results are given multiple proofs when each argument has something to contribute.