Selective dissemination of information

What is Selective Dissemination of Information (SDI)?

SDI, or sometimes called current awareness services or more plainly as selectivity, is the ability of a service to notify a client of material that matches the interests of the client.

This involves:

In that way, the client can decide whether or not to go ahead with acquiring the material or to wait for other information.

It should be remembered that SDI is usually more than just presenting the title, author's name and source reference to a client. It also involves some scanning and abstracting of all the main ideas or concepts in the material. As Tom Whitehall, author and editor of Practical Current Awareness Services from Libraries, said:

"Notifications of potentially useful material need to contain enough information about the item for a client to decide whether it is worthwhile obtaining and reading the original. A title, author's name and source reference is seldom enough." (1)

Good selectivity is also dependent on the ability of the individual or computerised system to keep up with the changing information needs of the clients. As Whitehall said:

"Good selectivity is also dependent on scanners' keeping up with changes in the work of their clients." (2)

And good selectivity involves arranging and presenting the information in a simple and pleasing manner for ease of use and quicker browsing by the clients. As Whitehall said:

"The arrangement of lists and bulletins and the reading load presented to the client by a current awareness service are crucial considerations, as is ease of access to the original material." (3)

Thus the whole purpose of SDI is to save time and money for the clients by making them aware of certain things — products, services and sources of information — relevant to their area of interest.

It is essentially a form of advertising/publishing for the information service provider (e.g. the librarian), to let interested people know of what is available in their field of interest.

Can people make money from this service?

There is a potential for libraries to turn SDI into a commercial venture and so increase the funds available to libraries when developing a better service. This involves getting clients to subscribe to the services by paying an annual subscription fee.

Or libraries may choose to do nothing more than freely alert people to new publications at no cost to the client.

It all depends on the demand on librarians to provide such services to clients.

How selective information is distributed?

The usual way to distribute selective information to clients is either by letter, email or, if the request from clients is common, by bulletin board on the Internet.

SDI is usually a personal service and, as such, it is usually done by letter or email to each client. As Whitehall said:

"SDI is a more personal service—each client receives notifications of just those items which seem useful to him or her." (4)

However, with the exponential growth of information accumulating together with an increasing demand for easy, up-to-date and low-cost access to selective information, the best medium available to do the job properly is via the Internet.

Why computerised/online SDI services?

There are two main types of SDI services: (i) the in-house SDI service where individuals scan through the material; and (ii) the computerised SDI service where a machine does literally all the work.

Why the move to computerised SDI in recent times? Whitehall puts it this way:

"[Some companies] explained that the move to computerised SDI avoided labour-intensive manual techniques, and was necessary anyway because of the rapid expansion of the world's literature." (5)

There is also another argument favouring the computerised SDI approach:

"...the user is the only reliable judge of relevance, and using an intermediary between him and the published literature is a system of doubtful merit. Instead a system where the researcher selects his own literature by his search profile, which he adjusts himself, is preferable." (6)

But others felt the move was more to do with minimising the cost of the service without much regard for whether it was the best option. D. V. Arnold, author of Structure of information services, published in Aslib Proceedings in December 1972, said:

"Computerised SDIs supplied from outside are by no means necessarily the final and even the best answer, and it must be acknowledged that much of the pressure to use them has been dictated by financial stringency." (7)

If there is a cost, what's the most expensive part of SDI? It seems manual scanning is considered the most expensive part of delivering SDI services. As Whitehall explains:

"...senior management...have forced information units to disband in-house provision of current awareness [services] because they saw the manual scanning involved as labour-intensive and noticeably costly." (8)

And who is responsible for this move towards computerised SDIs—the technology, or people?

Whitehall makes it clear that it is the people—namely, senior management—who have to be credited or blamed for the change:

"The age of "new technology" alone is not sufficient to explain the large-scale movement towards computerisation....Part of the praise, or blame, has to be laid at the door of senior management, whose needs to introduce more cost-efficiency into company operations have to be acted upon by middle managers such as librarians and information officers.

'In its most extreme form the need of senior management for cost-efficiency has caused the complete abandonement of information services....

'A less extreme approach is for management to "interfere" in the operation or organisation of an existing information service, by looking askance at manual operations, and pointing to the increased cost-efficiency of computerisation." (9)

But some argue that the move to computerised SDIs for greater cost-efficiency has come at the expense of (i) a less personalised service where the clients needs are not always and thoroughly catered for with adequate depth, quality and concise information; and (ii) certain computerised SDI services have the tendency to be large and broad to help satisfy a very large number of clients.

Whitehall believes the real solution lies in a balance between in-house and computerised SDIs:

"The information units in organisations where senior management is content to take a more passive role, or where the benefits of complete information are seen as vital to company survival, are the ones which have profited from the 1980s. They have had money made available for computers and yet have been able to retain traditional, more effective current awareness methods as well." (10)

At any rate, the move to computerised SDIs certainly began in the 1970s:

"The early seventies proved to be a turning point, with economic factors replacing the needs of the users as the number one priority." (11)

Then in the 1990s, online SDIs became the natural extension to computerised SDIs. Because, with the advent of the Internet, there came certain advantages.

The power of the Internet

The internet is not just an excellent tool for communicating ideas with vast numbers of people around the world. It has the power of reducing the cost:

With respect to SDI services, Whitehall states that:

"...computers mean that time can be saved in [SDI] bulletin compilation, and that the production of current awareness notifications can be made more flexible. New technology also means the possibility of a local network on which current information can be used as soon as it has been extracted from the literature. More immediate access is possible to new information, and also wider dissemination of the material occurs." (12)

He also argues that with computers it is easy to build up an in-house 'current awareness' database of material and then to have it easily indexed, searched and accessed by a wide group of people in a way that meets the precise needs of every client.

So this brings us to the question of how many libraries have gone computerised and online in providing automatic SDI services and how quickly can specific information be found.

In 1986, not enough libraries were taking advantage of online SDI bulletin according to Whitehall:

"A few organisations have made their information bulletin available on-line....However, widespread use of an on-line bulletin is seen as taking five to ten years, as professionals of the "punched-card" generation retire and younger people with a background of on-line computing come into the organisation." (13)

Today, one can expect a reasonable number of libraries would have made the transition to online SDI services. But further research is required in this area.

The problem with the Internet

Assuming people know their local library has a quality online SDI service, then how quickly people can find specific and relevant information depends on how well the online service can pick out, present and organise the information.

Similarly, if people don't know which SDI service is actually best on the Internet, searching for a suitable SDI service online can be a bit tricky. Even the so-called online search engines like Google and Yahoo are not powerful enough to search through the maze of web sites to select the very best SDI service.

As Angus Kidman, editor-in-chief of Australian Personal Computer, wrote in the October 2000 issue:

"...the fundamental problem with search engines: they're not very good and they miss a lot of stuff." (14)

Other barriers to online SDI include the presence of different languages spoken by people around the world and how non-English speaking material can be easily missed in SDI services. The next for automatic translation of such information is a must, such as the free Google Translate service.

What needs to happen here? Should we ask the librarian to do all the work of finding specific information for clients by choosing the best SDI service web sites and even do the actual service itself, including translating foreign material into a readable format? Should we ask Google and other online services to provide better search engines?

Or do we ask for better quality information in a suitable digital format to be made available to libraries from publishers so library users can use computers to do the worldwide scanning and selecting of information on their own?


If librarians are really serious about providing truly in depth and quality information selection using a computerised SDI system, then they must consider developing a special kind of electronic analytic catalogue system.

One such system is the PDF format for publications combined with Adobe Acrobat Catalog for cataloguing PDF publications. All that is required is for all publishers to start providing their journals and books in the PDF format, distribute them to libraries via the email system, letting the librarians use their computer to automatically catalog the PDF publications overnight (where each word in the publications is turned into an access point), and then make available online both the catalog and the PDF publications for people to access.

Such a system should solve many of the problems the clients and librarians may have about traditional SDI services. All that remains is a powerful foreign language translation service to convert all text into any language we want.

Certainly, Google is well on its way to achieving just that for users. Does this mean we have the ultimate virtual librarian in our midst? Do we really need libraries and librarians at all?