The extent of data collection during an IS audit should be determined primarily by what factor?

The extent of data collection during an information systems audit is fundamentally guided by the purpose and scope of the audit. This factor defines the specific objectives that the audit seeks to accomplish, which in turn dictates what data is necessary to adequately assess and evaluate the information systems in question.

Understanding the purpose and scope ensures that the audit is focused and relevant, allowing the auditor to align their efforts with organizational goals, compliance requirements, and risk assessments. For example, if the audit's objective is to evaluate compliance with regulatory requirements, the data collected will be more focused on that specific area. Conversely, if the purpose involves a comprehensive risk assessment, a broader range of data would be needed.

In contrast, the availability of critical information, the auditor's familiarity with the circumstances, and the auditee's ability to find relevant evidence may influence the data collection process, but they do not fundamentally define the extent of data needed. The purpose and scope serve as the guiding principles to ensure that the audit remains efficient, effective, and aligned with its objectives.