The design of a graphical sign involves its creation by the designer followed by testing for its interpretability using established testing methods.But the results of these tests can be misleading due to inexplicable factors like cultural knowledge, immediate environment, and ability to process information at the user’s end, and thus they can demonstrate agreement even for ambiguous signs. This points out another problem in the test results: they do not guarantee the quality of the sign. Signs that aim to become international standards, especially, should achieve maximum possible clarity in their message and quality in their design. which is also why it’s important to ensure that the sign submitted for testing represents the designer’s finest work. This study further investigates the designer’s process of creating a sign and presents a method to achieve a reasonable level of confidence in the designer of its comprehensibility. Then, additional testing of such a sign will be necessary to verify the designer’s prediction.