The fact of the matter is that human knowledge is very messy so organizing it according to fixed rules is difficult. That's why people have trouble finding things in their own houses - even though they live there and made up the rules, it still doesn't make sense. If you want to understand how technology is changing cataloging, you first need to understand how technology is changing the information resources that we use. The important thing to know is that technology is directly responsible for three related trends which affect how information resources are created, distributed, and accessed. The first of these trends is the rise of electronic resources.
Electronic resources are much more amorphous and interactive than their print counterparts.
They are more flexible in the sense that they can be changed to fit an individual's needs. They are easy to transmit and convert. However, they are also much more unstable. Electronic resources are frequently moved, deleted, or modified. The second major trend is the decentralization of information.