What is "substantial doubt"?

A study tries to determine if perceptual differences exist among key groups of audit opinion users and professional auditors concerning the meaning of the so-called "substantial doubt" expression used in the context of Statement on Auditing Standards Nos. 59 and 64. Results of a survey of 5 samples of audit opinion users reveal statistically significant differences among subject groups. In comparison to auditors, bankers and financial analysts perceive substantial doubt as a relatively high numerical probability, while judges and legislative staff members view substantial doubt as a relatively low numerical probability value. This suggests that financial statement users may believe that substantial doubt connotes greater assurance of an audit client's financial demise than intended by auditors.