Card sorting is a method of determining the optimum organization--the Information Architecture (IA)--of a website. Elements of the website are represented by cards and the participants are asked to group the cards wth other cards that they would expect to find together. This method is perfect if you are embarking on a redesign.
The type of card sort you decide to perform will depend on what and how much information you seek and need. This method also requires some background knowledge about best practices. We recommend reading about Card Sorting on Usability.gov.
The ratings on the left refer to our experience using an open group card sort. Other types of card sorts may have slightly different outcomes.
How to do Card Sorting
Online vs. In-Person
The first decision you'll have to make is whether to conduct the card sort yourself in-person or to use one of the many online applications to conduct the card sorts remotely. There are benefits and shortcomings to each:
In-Person: you can watch the decision making in action, and hear about why your users group different elements together, especially if you recruit groups of users to perform the card sort collaboratively. The downsidse are the amount of time it takes, the difficulty scheduling your subjects to come in, especially if you want to have groups perform the card sort, and analyzing the results yourself.
Online: you do not need to set aside time to observe the card sorts, and it is easier to recruit subjects, because they can do it whenever they have time; so the potential to have more subjects involved is higher. Another benefit to the online version is that the application will do the results analysis for you. The downside is that you do not get to watch the subjects as they make the decisions or have a chance to ask clarifying questions.
Preparing the Cards
Regardless of whether you are conducting an open or closed card sort (see the description above), you will need to identify the elements of your website that you want to have sorted by the card sort participants. Recommendations for the number of elements varies widely. We used around 50 items, and found that it worked well.
Online - you will enter the names of the website elements into the software.
In-Person - you will create index cards or sticky notes with the names of the website elements for people to physically manipulate and group.
Collecting and Analyzing Card Sorting Data
This pertains only to In-Person Card Sorts.
Collecting the Data
You will want to capture the groupings your users create. If you are going to have back-to-back card sort sessions, you may want to take a picture of the groups as they are laid out on the table so that you can quickly reuse the cards you created. If you have more time, you can simply gather the cards into their groups and transfer that information into your organization scheme.
Your organization scheme will depend on the method you will use to analyze the data, but you will most likely start by entering the groups into a spreadsheet.
Analyzing the Data
The goal with card sorting is to create a dendrogram that clusters the cards that are most commonly grouped together.
Here are some guides for conducting the analysis
Card Sorting Tools
Low Tech - Index Cards
Online Sorting Applications
OptimalSort seems to be the most popular choice for online card sorts, and they seem to have bought up just about all of their competitors. At $109/month, it isn't cheap. It does allow unlimited users, unlimited cards, and logo customization.
This is another pay site that supports both open and closed sorting with unlimited users and cards. It is even available for tablets.
This one seems to be the most affordable choice at $24.95/month, but probably doesn't have all of the bells and whistles. It does allow unlimited number of users, but isn't clear on the number of cards.
I'm sure there are many choices out there. For affordability, we went with the open source product called R. You can download it from The R Project for Statistical Computing site.
You'll need to enter this code into the software, remembering to change the last line of code so that it reads the location on your computer where you stored the csv file with the group data you collected.