COOL links: ride the wave

Michael Miller and L. Jay Wantz

Intelligent Automation, Inc., Rockville, MD 20850, U.S.A. and

As the Web evolves it is likely to become more user-centered, where navigation and search are more personalized and individualized. Signs of this are already surfacing in various guises including filters and other censorship tools, the use of cookies as user profile repositories, and metadata-aided search. Whether the user-centered approach will become the predominant model is open to debate, but it does appear that it will continue to make inroads. With minimal adaptations the technology available today can better manage and deliver the vast amount of information on the Web by meeting the user's needs, goals, and preferences. This paper discuss one such adaptation: COOL links. These are multi-ended, computed hyperlinks, which foster a new model of Web navigation, applicable to a variety of disparate domains, including education and marketing.

Multi-ended hyperlink; Computed hyperlink; User-centered navigation; Individualization; User profiles

1. Introduction

Today's Web navigation features user manually selecting their own path through single-ended "hot" links. This user-directed approach, though successful and useful for many purposes, has a number of drawbacks, which, as more and more information becomes available on the Web, seem to loom larger. In particular, navigation is often punctuated by frequent and lengthy searches and dead-end paths through irrelevant, undesired, unsolicited or inappropriate information. The result is that the user is often unaware of relevant aspects of a collection of resources until he or she has navigated through much unwanted material. In addition, it is not unusual that clicking on a link leads to surprises, irrelevant paths, or a feeling of being lost in "cyberspace."

Traditional navigation ignores an individual's specific preferences, needs, or other abilities (e.g., reading level). This can be particularly problematic when the user is under time, or learning and comprehension constraints, as in educational situations. An alternative is automated guidance toward material that is of interest, contextually relevant, and appropriate for the user. In an educational setting it would be useful for a learner to be guided along a path of Web resources which meet his or her educational needs. In the commercial arena it would be useful to direct the Web user to those products and services in which he or she might be especially interested.

Notable examples of such non-traditional approaches are: Walden's Paths [1], WebWatcher [2] and Letizia [3]. These systems have shown some promise, especially in locating pages similar to those already found to be of interest to the user, but stop short of locating Web resources for specific users with specific educational needs and goals. With minimal adaptations and the technology available today, the vast amount of information on the Web can be even better managed and delivered to the meet the user's needs, goals, preferences and attributes. COOL links [5] are one such adaptation.

2. Not all link types are created equal

Most familiar to the Web community is the HTML "hot" link, denoted by the familiar href tag in an anchor block. Each link of this type is intended to refer to the address of exactly one resource, which itself is denoted statically in the HTML. Thus, one of the prime attributes and attractions of these links is that they are unambiguous. Another is that the HTML author knows exactly where a viewer of the page will "go" if a link is clicked.

Other link types exist — for instance multi-ended links — and have been implemented in a variety of hypermedia applications, but typically not the Web. At first it seems that a multi-ended link — one which "refers" to multiple resources — applied to the Web would be ambiguous. To which of the multiple resources is the user taken when the link is clicked?

COOL links are an example of multi-ended, Web links that are not ambiguous. This is accomplished by letting these links "refer" to a collection of resources only until click-time. Then a single resource is selected from the collection by some evaluation scheme. A COOL link could look something like:


where metadata_description_of_resource_i refers to (the location of) some metatdata characterization of the resource located at url_of_resource_i. (Note: The element COOLREF does not currently exist in any HTML standard. It is a used for exposition purposes. Our current implementation of COOL links uses a Javascript simulation of the COOLREF element. The url_of_resource_i terms are also for the reader's benefit. Most metatdata standards permit metadata to reside outside of the described resource. In those cases the metadata itself contains a reference to the resource's URL.)

The resources associated with a COOL link are unordered. There is no special significance given to those that appear closer to the start of the link description than those that appear nearer the end. Instead, when a COOL link is clicked the metadata of each component resource is evaluated and compared against a separate set of input parameters, for instance the user's profile, and the "best-fit" resource is returned.

Presumably, each distinct resource in a COOL link collection provides different benefits to different users (though each resource may contain information about the same subject or topic). The burden of choosing a link component from the collection is placed upon the browsing tool (or a plug-in) at runtime.

In summary, the four-part COOL link machinery contains: (i)The link itself, (ii)selection algorithm(s), (iii)external input features such as user profiles, and (iv)meta-descriptions of the link's associated resources.

3. Applications

COOL links are applicable in a variety of domains and in a variety of different ways, including:

Education: Students tend to progress at their own pace, learn differently, and have a diverse set of skills, even though they are following the same lesson. Ideally, an instructor takes a student's characteristics into account, and teaches accordingly. COOL links can serve as a tool to facilitate lesson individualization in an electronic learning environment. As students navigate Web-based lesson material templates, they can be guided on a path that is most appropriate to their learning goals and capabilities. A link selection mechanism determines a path dynamically as a student browses through courseware containing COOL links. An instructor or lesson developer can create a single lesson plan template which contains different material for use by students with differing needs. Attributes like the pedagogical "appropriateness," associated grade level, and readability index of a resource in relation to a student's profile may weigh heavily on the choices made by the selection mechanism.

User-centric navigation: A great deal of research has been carried out on Web trails, paths and guided tours [4]. Trails tend to be contextually relevant and interesting to the user, but are not necessarily shaped by characteristics of the individual user himself. Taking these characteristics into account leads to user-centric navigation (UCN) — the automated guidance of an individual through the Web [5]. UCN is a paradigm shift from the more passive modes of hypertext navigation as it facilitates the development of dynamic trails based upon context, user interaction and user needs.

Advertising, marketing and sales: The colour, size, cost, or style of a particular consumer item in relation to a consumer's preferences may affect his or her desire to purchase an item. Additionally, other attributes of the consumer like background, gender, age, career and income will affect the likelihood of a purchase. With advertising and sales a mainstay of the Web, sellers are looking for ways to direct those most interested in their products to their pages. COOL links, together with user profile data, are one way to accomplish some amount of successful marketing, and in the process eliminate large numbers of unwanted hits.

4. Conclusion

As the Web continues to grow, more and more information will become available. Experience has shown that the more information available, the harder it will be to find what we want unless some measures are taken to better tailor navigation and searching technologies. There will continue to be times that traditional user-directed Web navigation will be entertaining and informative, but there will be other times when it will be frustrating and wasteful. Multi-ended, computed COOL links offer a new way to view the Web, with minimal impact on the existing Web architecture. With the current emphasis placed on metadata and user profiling, and the mounting frustrations stemming from wasted time spent searching for resources, we hope that COOL links will continue to make inroads into the Web, especially as new applications highlight their benefit and exemplify their utility.


This research and development was supported (in part) by DARPA contract #N66001-95-C-8626, and US Department of Defense Education Activity (DoDEA) contract #N66001-97-M-C528.


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