Resources - Who's who in the Who's Who stakes?. The venerable Who's Who is available online from both KnowUK and Xreferplus. IWR pits them against each other in a head-to-head test to find out which of the two interfaces offers the best access to this indispensable resource. Mark Chillingworth adjudicates.

It has been considered as the ultimate accolade - an entry in Who's Who. But the venerable A&C Black title serves as an indispensable resource for information professionals and researchers. Who's Who 2005 and Who Was Who 1897-2004 have been added to the Xreferplus and KnowUK information platforms from reference specialists Xrefer and ProQuest, respectively. So how do they compare, and what do they offer?

Who's Who was first published by A&C Black in 1897 and became a cultural icon as the big red book of who is and was important. Unlike the extensive articles in the Dictionary of National Biography from Oxford University Press, Who's Who is a more condensed information resource, with each entry receiving a brief, but highly detailed biography.

Xreferplus is a clean and well designed interface. Once logged in, users are taken to the main Xreferplus menu of topics - such as art, medicine, food, music, geography and quotations - with the link to Who's Who listed in the biography channel. All listings are in alphabetical order and as a result the Who's Who titles appear at the bottom of the list.

KnowUK has split the Who's Who 2005 and Who Was Who titles within its interface, unlike Xrefer, which groups them together. KnowUK's biography channel is focused around the search engine, with a search panel at the top of the window and a list of biography resources that can be selected by ticking the boxes. Users can also search Who's Who in Education and Who's Who for Northern Ireland and Scotland as separate resources.

Xreferplus has a search panel at the top of the window, but its setup suits browsing and we found it easier to discover a wider range of information by browsing rather than using the search engine. Users can browse channels for occupation, companies, education, addresses, birthdays and recreations. All pages within Xrefer are clean and simple, with the pink corporate branding adding some colour to the resources.

KnowUK has a bolder look to its pages with blue frames and stripes across the screen dividing the sections of core data and biography. Because the KnowUK interface is built around a search engine that allows you to browse a number of biographical databases, it is not obvious that you can search by university, town, company and birth years. Searching by dates is not as clear on KnowUK as there is no interface ...