Card sorting is a technique that many information architects (and related professionals.) use as an input to the structure of a site or product. With so many of us using the technique, why would we need to write an article on it?
While card sorting is described in a few texts and a number of sites, most descriptions are brief. There is not a definitive article that describes the technique and its variants and explains the issues to watch out for. Given the number of questions posted to discussion groups, and discussions we have had at conferences, we thought it was time to get all of the issues in one place.
This article provides a detailed description of the basic technique, with some focus on using the technique for more complex sites. This article does not cover some issues such as the use of online tools, which will be covered in a future article.
Why
Card sorting is a quick, inexpensive, and reliable method, which serves as input into your information design process. Card sorting generates an overall structure for your information, as well as suggestions for navigation, menus, and possible taxonomies.
While card sorting might not provide you with final structure, it can help you answer many questions you will need to tackle throughout the information design phase. For example, more than likely there will be some areas that users disagree on regarding groupings or labels. In these cases, card sorting can help identify trends, such as:
- Do the users want to see the information grouped by subject, process, business group, or information type?
- How similar are the needs of the different user groups? >
- How different are their needs?
- How many potential main categories are there? (typically relates to navigation)
- What should those groups be called?
Card sorting can help answer these types of questions, making you better equipped to tackle the information design phase.
Definition
Card sorting is a user-centered design method for increasing a system’s findability. The process involves sorting a series of cards, each labeled with a piece of content or functionality, into groups that make sense to users or participants.
According to Information Architecture for the World Wide Web, card sorting “can provide insight into users’ mental models, illuminating the way that they often tacitly group, sort and label tasks and content within their own heads.”
Card sorting is a great, reliable, inexpensive method for finding patterns in how users would expect to find content or functionality. Those patterns are often referred to as the users’ mental model. By understanding the users’ mental model, we can increase findability, which in turn makes the product easier to use.
Method
There are two primary methods for performing card sorts.
- Open Card Sorting: Participants are given cards showing site content with no pre-established groupings. They are asked to sort cards into groups that they feel are appropriate and then describe each group. Open card sorting is useful as input to information structures in new or existing sites and products.
- Closed Card Sorting: Participants are given cards showing site content with an established initial set of primary groups. Participants are asked to place cards into these pre-established primary groups. Closed card sorting is useful when adding new content to an existing structure, or for gaining additional feedback after an open card sort.
Closed card sorting will be detailed in a future article.
Advantages and disadvantages
As with any other method, card sorting has both advantages and disadvantages. Keeping these in mind will help you determine whether the technique is appropriate for your situation and make decisions about how you run the activity.
Advantages
- Simple – Card sorts are easy for the organizer and the participants.
- Cheap – Typically the cost is a stack of 3×5 index cards, sticky notes, a pen or printing labels, and your time.
- Quick to execute – You can perform several sorts in a short period of time, which provides you with a significant amount of data.
- Established – The technique has been used for over 10 years, by many designers.
- Involves users – Because the information structure suggested by a card sort is based on real user input, not the gut feeling or strong opinions of a designer, information architect, or key stakeholder, it should be easier to use.
- Provides a good foundation – It’s not a silver bullet, but it does provide a good foundation for the structure of a site or product.
Disadvantages
- Does not consider users’ tasks – Card sorting is an inherently content-centric technique. If used without considering users’ tasks, it may lead to an information structure that is not usable when users are attempting real tasks. An information needs analysis or task analysis is necessary to ensure that the content being sorted meets user needs and that the resulting information structure allows users to achieve tasks.
- Results may vary –The card sort may provide fairly consistent results between participants, or may vary widely.
- Analysis can be time consuming – The sorting is quick, but the analysis of the data can be difficult and time consuming, particularly if there is little consistency between participants.
- May capture “surface” characteristics only – Participants may not consider what the content is about or how they would use it to complete a task and may just sort it by surface characteristics such as document types.
When should card sorting be used?
Card sorting is a user-centered, formative technique. It should be used as an input to:
- designing a new site
- designing a new area of a site
- redesigning a site
Card sorting is not an evaluation technique and will not tell you what is wrong with your current site.
Card sorting is not a silver bullet to create an information structure. It is one input in a user-centered design process and should complement other activities such as information needs analysis, task analysis, and continual usability evaluation. It is most effective once you have completed:
- research into what users need out of the site
- a content (functionality) audit/inventory (for an existing site) or detailed content list (for a new site). For an existing site, it is crucial that the content inventory is examined carefully to include only content that is needed by users.
Card sorting will provide benefit to most sites, but can be challenging to use against some sets of information. The table below summarizes when card sorting works well and provides good results, and when it is challenging both to run and to analyze.
