Special Topics - Measuring the User Experience: Collecting, Analyzing, and Presenting Usability Metrics - page 220

Using these rules, the distance matrix for the preceding participant would
look like what's shown in Table 9.7 .

Table 9.7 Distance matrix for one participant in the fruit card-sorting example.
Apples Oranges Strawberries Bananas Peaches Plums Tomatoes Pears Grapes Cherries

Apples — 0 1 1 0 1 0 1 1 1

Oranges — 1 1 0 1 0 1 1 1

Strawberries — 1 1 0 1 1 0 0

Bananas — 1 1 1 0 1 1

Peaches — 1 0 1 1 1

Plums —— 1 1 0 0

Tomatoes — 1 1 1

Pears — 1 1

Grapes — 0

Cherries —

Table 9.7 Distance matrix for one participant in the fruit card-sorting example.

CARD-SORT ANALYSIS SPREADSHEETS

Donna Maurer has developed an Excel spreadsheet for the analysis of card-sorting
data. She uses some very different techniques for exploring the results of a card-sorting
exercise than the more statistical techniques we're describing here, including support
for the person doing the analysis to standardize the categories by grouping the ones
that are similar. The spreadsheet and instructions can be downloaded from http://www.
rosenfeldmedia.com/books/cardsorting/blog/card_sort_analysis_spreadsheet/ .

In addition, Mike Rice has developed a spreadsheet for creating a co-occurrence matrix
from card-sorting data. This type of analysis allows you to see how often any two
cards were sorted into the same group. His analysis spreadsheet works with the same
spreadsheets that Donna Maurer uses for her analyses. Mike's analysis spreadsheet,
and the instructions for using it, can be found at http://www.informoire.com/
co-occurrence-matrix/ .

We're only showing the top half of the matrix for simplicity, but the bottom
half would be exactly the same. The diagonal entries are not meaningful because
the distance of a card from itself is undefined. (Or it can be assumed to be zero
if needed in the analyses.) So for any one participant in the study, the entries
in this matrix will only be 0's or 1's. The key is to then combine these matrices
for all the participants in the study. Let's assume you had 20 participants do the
card-sorting exercise with the fruits. You can then sum the matrices for the 20
participants. This will create an overall distance matrix whose values can, in the-
ory, range from 0 (if all participants put that pair into the same group) to 20 (if
all participants put that pair into different groups). The higher the number, the