A day in the life of BBCi Search - part 3

 by Martin Belam, 27 March 2003

Advanced Search

'Advanced Search' is a general term describing different types of search syntax, including using quote-marks to force exact phrase matching, using '+' or '-' modifiers on search terms, or using Boolean constructions with AND, OR or NOT.

BBCi Search does not offer an explicit advanced search option, except on the BBC News area of the site. There are two reasons for this.

Firstly, the mix of technologies used on the site makes it difficult to provide a consistent advanced search option. When a search is made on the BBCi website, software internally known as "the wrapper" uses the referring URL to determine which of the search technologies employed by the BBC is required to answer the query. In some cases, the wrapper can make as many as four separate calls to different back-end technologies. All of these behave in different ways and understand different advanced search syntaxes, making it impossible to provide uniform functionality across the different indexes of the site. BBCi Search supports the advanced search syntax of each of its separate technologies, so the techniques can be successfully used on the site - but it is not made explicit to the users.

a diagramatical representation of the archectecture of BBCi Search

Secondly, the target audience for the service have shown in user-testing that they are unlikely to use such an advanced search service, and even find the provision of it confusing.

BBCi Search is aimed at novice and inexperienced internet users, and its goal is to provide the best results with the greatest simplicity for the user. The label "Advanced Search" implies that you have to be an 'expert' to use it, which is off-putting, and it also implies that because you are using the 'non-advanced' interface, you are somehow missing out.

Nevertheless we find that through prior learned behaviour, a proportion of BBCi users enter search strings that contain advanced search syntax. Analysing this behaviour shows that users were most likely to attempt to use advanced search between 6am and 9am in the morning, and between 3pm and 10pm in the evening, when around 5% of searches showed some attempt to use advanced search. Notably at the peak time for site usage, over the lunch period, users were only half as likely to use advanced techniques - around 2.5% of searches.

Further analysis of these searches themselves revealed that 1 in 5 attempts to use advanced search fail. This is because the users have either misunderstood advanced search syntax, for example, enclosing a one word search within quotes, or users have failed to spell all the words of their search correctly.

In part four of this article I will be looking at the level of incorrectly spelt words contained within search terms.

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