Ask a cross-section of people in the organization to complete it. Here are a few things to consider when interpreting the results of the questionnaire. One person's 5 is another's 3. The value lies in understanding the meanings people give to their scores. However, low to mid-range scores should be cause for concern.
Lower scores indicate fertile soil for the growth of resistance.
If so, this probably indicates that most people agree about support for change on that scale. Perhaps non-management staff consistently rate things low while supervisors rate things high. A pattern of high scores may indicate that the resistance will be Level 1 resistance limited to the change itself. The culture and history are such that people probably feel free to speak their minds. Therefore, conversations about the change should be easier to facilitate.