Below is what I could find about the WSI portion of the test.
The Work Styles Inventory (WSI) is a new product now available from Firefighter Selection, Inc. The WSI has been in development for three years. Several Ph.D. and graduate-level professionals conducted extensive research to identify and measure key traits that are needed for predicting job success as a firefighter. This test is designed to measure traits required for maintaining effective relations with co-workers in the station and while working with the public. To help make the WSI more effective, it was designed to measure these critical traits in ways that are less obvious than other personality-type tests. The WSI offers a new dimension to screening entry-level firefighter applicants and contains questions that will predict your applicants’ performance in the following areas:
Effective teamwork while co-habitating in the station environment
Thoroughness and attention to detail
Commitment and devotion
Receiving and responding to orders or instructions
Fire suppression, rescue, and forcible entry duties
EMS duties
Inspection duties
Station and apparatus/equipment maintenance duties (while working independently)
Station and apparatus/equipment maintenance duties (while working with others)
Overall job performance (the sum of all the above)
The WSI is a 40-minute paper-and-pencil examination, and is recommended that it be combined with other written tests. If the WSI is used in combination with other written firefighter tests, weights can be created based on the score achieved on the test. If the WSI is not combined with other written tests, the WSI can be used to create band scores of applicants who pass an initial written test.

