[R] test for difference in the order of self generated sequence

[Kaiya Liu]

Hello,

I have an experiment in which we ask subjects to generate a list of thoughts
after being exposed to a stimuli. The thoughts were then coded into two
categories (e.g. A & B). The objective is to show that the order in which
thoughts are generated is affected by the experimental conditions. Can
somebody tell me what functions in R can help me do the test or point me to
the appropriate reference? Thanks!

Example data: Subject 1 in condition 1 generated 5 thoughts. The first,
second, and 5th thought is in category A, thought 3 and 4 are in category B.
Subject 2 only generated 4 thoughts.

-------Condition-------------A-----------------B--------
n1       1                                1, 2, 5                  3, 4
n2       2                                3, 4                      1, 2
-----------------------------------------------------------

Kaiya Liu