The major question which internal control questionnaires are designed to answer is
‗How good is the system of controls?‘ Its primary purpose being to evaluate the system. One of the most effective ways of designing an internal control questionnaire is to phrase the question so that all the answers can be given as YES or NO, when a NO, will indicate a weakness in the system.
Whereas internal control questionnaires tend to ask separate questions in relation to each individual aspect of internal control, internal control evaluation questionnaires tend to concentrate on key questions.
Internal control questionnaires and internal control evaluation questionnaires both have an important role to play in the evaluation of systems. ICQs have the added advantage that they can infact help to document the system as well, whereas internal control evaluation questionnaires are perhaps more useful in focusing attention on the more important aspects of control systems.