Requirements Engineering (RE) activities require intensive communication to capture clients' requirements. As culture influences the way in which people communicate and interact, individuals' culture might influence the implementation of RE activities. In this paper, we discuss the differences between formal approach (using the framework we propose) and case-study-based approaches for the identification of cultural influences in RE. We compared the results of the application of our framework with the results of case studies conducted by other researchers from several cultures. The results showed that the framework provided a much higher degree of precision than expected: the framework identified almost all of the cultural influences mentioned in the identified cases studies. This provides evidence of the accuracy and validity of our framework, which can provide similar conclusions based on information about the cultures involved rather than in-depth analysis.