Use Cases for Taxonomy Development

Developing use cases in the initial design of a taxonomy is something I did not learn about until I went into consulting, but it is a useful approach to taxonomy and metadata design in any circumstance, regardless of the involvement of an external taxonomy consultant.
The use case technique comes from the field of systems analysis, and especially software and systems engineering, but use cases are increasingly applied in the development of systems and structures for knowledge management, content management, information management, etc. Typically use cases for a taxonomy are not limited to the taxonomy alone but are for the design of all metadata and the broader information or knowledge management system. “System” means the combination of software, content, metadata/taxonomies, and users.

What is a use case?

A use case describes a scenario of how a user uses a system to accomplish a particular goal. A use case should not be confused with a case study. It need not be long and detailed, although they may vary in their descriptive length. All use cases include:

1. A designated user type and role (sometimes called “actor”), which could be as simple as an internal organization job title. Examples of external users could be designated as: undergraduate college student, paralegal, pharmaceutical corporate librarian, experienced online shopper, etc.
2. A task that the user is engaged in which uses the system. This will likely be described in more detail than the description of the user. Taxonomy use cases would typically involve a specific aspect of one of the following tasks: indexing/tagging, using search to find information, using browse to find information, discovering/exploring for related information and finding/retrieving certain content items
3. A goal and perhaps ultimate purpose of the user’s task.

I had participated in a consulting project once whereby the stakeholders were advised to create use cases that went so far as identifying fictitious personas, a practice that is often done in marketing planning. I don’t think it’s necessary to go that far in taxonomy use case development, although it might be useful if there are users of the taxonomy who are external customers/clients.

Why create use cases for taxonomies and other metadata?

The task of developing taxonomies and other metadata can benefit from use cases in particular ways:

• It grounds the taxonomy in reality, ensuring that it is designed to be usable, rather than being an academic taxonomy on a subject domain.
• It engages the users and other stakeholders in the taxonomy development process, who then become more interested in supporting/promoting or using the taxonomy, especially when the taxonomy serves their user needs and solves their problems.
• It provides sample situations which can then be utilized for testing the draft taxonomy before the taxonomy and content are fully implemented in the system. As a taxonomist who has led taxonomy testing activities among sample users, I have personally found used cases to be valuable for this purpose. 

What are examples of use cases for taxonomies and other metadata?

The following brief fictitious use case examples are of the kind that could be used for taxonomy development.

Internal organization use cases:

• A subject-matter-expert author who is required to tag authored documents with subject categories so that users can find documents by subject.
• A digital asset manager in an advertising agency, who needs to ensure that image files are assigned the proper copyright information.
• A content manager at a publishing company who, as a major responsibility, needs to assign full metadata to XML file content for various downstream purposes to assembly digital content products.
• A marketing copywriter seeking an expert on a specific subject among a company’s employees to give feedback on the accuracy of a blog post the copywriter is writing and who is inclined to browse subjects if available. 
• A manager who wants to find historical information on product offered in order to prepare a presentation about the product.
• A digital marketer who needs to update the public website with seasonal images that were not used last year (but two years ago is OK).

External/customer use cases:

• An undergraduate student who uses the default search to look for information on the events leading up to the fall of the Berlin Wall for a history class paper.
• An experienced online shopper who is searching to purchase carry-on luggage and wants to filter results by price, color, and positive reviews.
• A corporate librarian conducting competitive intelligence research on market strategies of leading competitor companies in the same industry and who would like to use advance and/or Boolean searching, if possible.
• A lawyer specialized in commercial law who need to find out where and how to file a financing statement in the proper jurisdiction for a client of his who to secure a loan, but lacks experience in legal research.
• A cancer patient searching for an oncologist with a certain type of cancer specialty, acceptance of certain insurance, within a certain geographic region, and with a number of good patient reviews.
• A compliance officer who needs to find regulations and associated policies and procedures that pertain to various departments and products lines of his employer, who knows the names of statutes but not the titles of associated regulations.

How are taxonomy use cases utilized?

In addition to serving the purposes of engaging stakeholders and ensuring the taxonomy is content- and user-focused, use cases can have additional specific applications, such as:

• Identifying or validating who all the different types of users are, so that their issues and feedback can be taken into consideration in the future.
• Suggesting improvements in the user interface design.
• Developing walk-through scenarios, with specific search criteria or topics of browsing spelled out, for offline testing of the taxonomy usability (including adequate depth and breadth) for both indexing/tagging and retrieval. (Read more at the post "Testing Taxonomies.")
• Providing scenarios that can be used in other taxonomy/knowledge management project research, such as ROI (return on investment) research.