|Expanding Access to Science and Technology (UNU, 1994, 462 pages)|
|Session 3: New technologies and media for information retrieval and transfer|
|Information retrieval: Theory, experiment, and operational systems|
We must first of all ask the question, Why does a user (scientist) approach an information retrieval system? The simple answer must be because of a need or wish or imagined need for information. However, the user's perception of this information need deserves some exploration.
In Taylor's classic paper, "Question-Negotiation and Information Seeking in Libraries" , four stages are identified:
(1) the visceral need (i.e. the user's gut feeling of a need for information);
(2) the verbalized need (the user's first attempt to put the information requirement into words);
(3) the formalized need (the user's expression of the requirement in terms acceptable to the system);
(4) the compromised need (the user's revised expression of the requirement after negotiation with the system).
The last two stages relate to the user's interaction with the system, which is discussed later.
Belkin has further analysed the origins of the visceral need. A user has a state of knowledge of the world, an internal knowledge structure of great complexity. The perception of an information need arises from a perceived problem with some part of this knowledge structure (which may not be a simple gap but some internal inconsistency, conflict with evidence, or whatever). Belkin has called this the "anomalous state of knowledge," or ASK 
The ASK hypothesis potentially has strong consequences for the design of information retrieval systems. Most systems in effect demand that the users specify the piece of information that they require, and aim to provide the items that fit the specification. The ASK hypothesis suggests instead a problem-solving approach, where the system cooperates with the user in an attempt to solve the perceived problem (or resolve the anomaly).
Although some of the ideas discussed below predate the ASK hypothesis and involve a rather more traditional approach to IR system design, the ASK idea will inform my discussion throughout. Something like the problem-solving approach will recur in later sections.