We do not know the lengths of the documents themselves. We cannot even determine the order of the entries. The loss of page numbers and of global context is the fundamental handicap to writing a good index. Even the best indexing programs cannot work around these obstacles because they are side-effects of the essential nature of online presentations. It is the indexer's responsibility to make accommodations for the environment.
Lost knowledge Let's invent a baseline index.
Notice how much information has been lost. Fortunately for us, these headings are descriptive enough so that we can confidently guess what they mean. Not all authors are as understanding of the user's needs, however. The Power of a Hot Wire From Shouting to Carrier Pigeon Hardware As indexers, it is our responsibility to do better. The web indexer can rate entries.