The software techniques used in search-engines are being constantly improved, but they are still far from perfect. We therefore offer a word of caution about the behaviour of some queries. Often the results expected by users are very different from those actually obtained.
The frequent disappointments and complaints about problems with today's search-engines can be better managed if some unsolved technical and operational problems are taken into consideration:
- The design of a program capable to deal with complex queries is a difficult task, mainly due to the ambiguity of ordinary language. In consequence, the search programs often contain errors and behave unpredictably. In a multilingual environment, like the EUROPA server, this type of problem is especially acute.
- A considerable number of documents on the web servers are not adequately structured to be retrieved via a search-engine. For instance, the differences between presentation information and content information are often unclear for the search program.
- The user instructions must be addressed to an extensive and varied population, where experts mix with first time users. This often leads to unsatisfactory results in the structure and contents of the manual.