The cancellation score is a measure of a professional's reliability. We encourage professionals not to cancel jobs. Of course, some cancellations do happen due to emergencies. A few cancellations over a long period of time is probably normal; however, a high cancellation to completion ratio may suggest a lack of reliability and should be considered during the hiring process.
To avoid surprises (regardless of a professional's cancellation score), use the in-app Chat and Call features to stay in touch with a confirmed professional.