Tuesday, November 21, 2006

Document Retrieval vs. Fact Retrieval - In Search for a Qualified User Interface


Today, if you are looking for information in the Web, you enter a set of keywords (query string) into a search engine and in return you will receive a list (= ordered set) of documents that are supposed to contain those keyword(s) (or their word stem). This list of documents (therefore 'document retrieval') is ordered according to the document's relevance with respect to the user's query string. 'Relevance' - at least for Google - refers to PageRank. To make it short, PageRank reflects the number of links referring to the document under consideration, each link weighted with its own relevance being adjusted by the number of total links starting at the document that contains this link (in addition with some black magic that is still under copyright restriction, see U.S. Patent 6285999).
But, is this list really what the user expects for an answer? O.k. meanwhile, we - the users - have become used to this kind of search engine interface. In fact, there exist books and courses about how to use search engines in order to get the information you want. Interesting fact is that it is the user, who has to get adapted to the search engine interface....and not vice versa.
Instead it should be the other way around. The search engine interface should get adapted to the user - and even better to each different user! But, how then should a search engine interface should look like? In fact, there are already search engines that are able to give the answer to simple questions ('What is the capital of Italy?'). But, they stil fail in answering more complex questions ('What was the reason for Galileo's house arrest?').

In real life - at least if you happen to have one - if you are in need for information, you have different possibilities to get it:

  1. If there is somebody you can ask, then ask.
  2. If there is nobody to ask, then look it up (e.g. in a book).
  3. If there is nobody to ask, and if there is no way to look it up, then think!

Let's consider the first two possibilities. Both do also have their drawbacks: Asking somebody is only helpful, if the person being asked does know the answer. (O.k., there is also the social aspect that you might get another reward just by making social contact...instead of getting the answer). If the person does not know the answer, maybe she/he knows, whom to ask or where to look it up. But we might consider this fact as being a kind of referential answer. On the other hand, even if the person does know the answer, she/he might not be able to communicate the answer. Maybe you speak different languages (not necessarely different languages in the sense of 'English' and 'Suaheli', but also consider a philosopher answering the question of an engineer...). Sometimes you have to read in between the lines to understand somebody's answer. At least, in some sense we have to 'adapt' to the way the other person is giving the answer to understand the answer.
Considering the other possibility of looking up the information, we have the same situation as if asking the www search engine. E.g., if we look up an article in an encyclopedia, we use our knowledge of how to access the encyclopedia (alphabetical order of entries, reading the article, considering links to other articles...being able to read...).
Have you realized that in both cases we have to adapt ourselves to an interface. Even when asking sombody, we have to adopt to way this person is talking to us (her/his level of expertise, background, context, language, etc.). From this point of view, adapting to the search engine interface of Google seems not to be such a bad thing at all....

If it comes to fact retrieval, the first thing to do is to understand the user's query. To understand an ordinary query (and not only a list of interconnected query keywords), natural language processing is the key (or even as they say the 'holy grail'). But even, if the query phrase can be parsed correctly, we have to consider (a) context and (b) the user's background knowledge. While the context helps to disambiguate and to find the correct meaning of the user's query, the user's background determines its level of expertise and the level of detail in which the answer is best suited for the user.

Thus, I propose that there is no such thing as 'the perfect user interface'. Anyway, different kind of interfaces might serve for different users in different situations. No matter how the interface will look like, we - the users - will adapt (because we are used to do that and we learn very quickly). Of course, if the search engine is able to identify the circumstances of the user (maybe she/he's retrieving information orally with a cell phone or the user is sitting in front of a keyboard with a huge display) the search engine may choose (according to the user's infrastructure) the suitable interface for entering the query as well as for presenting the answer...

2 comments:

Steffen said...

Hi Harald,

this post reminds me somehow on an old vision from John Sculley (former Apple CEO) named Knowledge Navigator (Wikipedia / Video). Already in 1987, people thought about the perfect user interface -- in this case ending up with a personal software agent that interacts with the user in natural language. The video is quit funny -- especially for deadline-stressed scientists ;-)

Cheers,
Steffen

hs said...

Hi Steffen,
thanks for your comment! I didn'tknow the Apple Knowledge Navigator, but the vision is quite interesting. A multi-modal agent based interface combined with natural language understanding....unfortunately, out of reach yet...