Self-report bias and mono-method bias pose significant threats to the validity of research in organizational behavior, hindering the development of theories. This paper presents a conceptual framework to understand factors influencing employees' motivation to bias their responses to organizational researchers. Using a longitudinal, multitrait-multimethod dataset, the paper illustrates various aspects of the problem and argues that traditional methods for controlling self-report bias are insufficient. The results suggest the need for developing a theory of method effects and companion analytic techniques to improve the accuracy of psychological research in business settings. Theoretical advances in organizational behavior and psychology depend on empirical confirmation. Theories supported by numerous studies become dominant, while those with mixed or null results fade. However, there is ongoing concern about the accuracy of commonly used methods in organizational research. Accurate measurement of organizational behavior is essential for advancing the field, but it is often considered a major shortcoming due to reliance on self-reports, which are easy to obtain and often the only feasible way to assess constructs. Sackett and Larson found that over a third of studies in organizational behavioral journals used questionnaires, with most relying solely on self-reports. Self-reports are prone to response bias, and common method variance can inflate inferences about correlations and causality. Schmitt suggested the need for a theory of method bias to understand and control for it. This paper applies existing knowledge of self-report and mono-method bias in business settings to constructs assessed in employee assistance and corporate health promotion research. It examines a general conceptual framework for understanding potential motivational biases in self-report questions and applies it specifically to corporate health promotion constructs.Self-report bias and mono-method bias pose significant threats to the validity of research in organizational behavior, hindering the development of theories. This paper presents a conceptual framework to understand factors influencing employees' motivation to bias their responses to organizational researchers. Using a longitudinal, multitrait-multimethod dataset, the paper illustrates various aspects of the problem and argues that traditional methods for controlling self-report bias are insufficient. The results suggest the need for developing a theory of method effects and companion analytic techniques to improve the accuracy of psychological research in business settings. Theoretical advances in organizational behavior and psychology depend on empirical confirmation. Theories supported by numerous studies become dominant, while those with mixed or null results fade. However, there is ongoing concern about the accuracy of commonly used methods in organizational research. Accurate measurement of organizational behavior is essential for advancing the field, but it is often considered a major shortcoming due to reliance on self-reports, which are easy to obtain and often the only feasible way to assess constructs. Sackett and Larson found that over a third of studies in organizational behavioral journals used questionnaires, with most relying solely on self-reports. Self-reports are prone to response bias, and common method variance can inflate inferences about correlations and causality. Schmitt suggested the need for a theory of method bias to understand and control for it. This paper applies existing knowledge of self-report and mono-method bias in business settings to constructs assessed in employee assistance and corporate health promotion research. It examines a general conceptual framework for understanding potential motivational biases in self-report questions and applies it specifically to corporate health promotion constructs.