The Self-Monitoring Scale by Snyder (1974) was found to have a stable factor structure that does not align with his five-component theoretical model. The authors describe sets of items that better reflect the theoretical structure and find that four of the five components are positively related to social anxiety. This challenges Snyder's theory and suggests a need for a narrower definition of self-monitoring. A revised 13-item Self-Monitoring Scale was developed, measuring sensitivity to others' expressive behavior and ability to modify self-presentation. A 20-item Concern for Appropriateness Scale was also introduced, measuring cross-situational variability and attention to social comparison information. Both scales have acceptable internal consistency and yield subscale scores. The theory of self-monitoring posits that individuals regulate self-presentation based on situational cues. However, recent studies failed to validate this theory, prompting a reevaluation of the scale. Factor analysis revealed three factors: acting ability, extraversion, and other-directedness, which do not align with Snyder's five components. The scale's factors correlate differently with other variables, indicating a mismatch between the scale and the construct. Study 1 examined the relevance of extraversion for self-monitoring and found that four items load together to define an extraversion factor. Study 2 developed five sets of items for each component of self-monitoring, resulting in a revised scale with four factors: cross-situational variability, acting ability, ability to modify self-presentation, and concern for appropriateness. Study 3 further refined the scale, leading to a 28-item version with four factors. Study 4 found that the revised scale better aligns with the theoretical structure and has higher internal consistency. The revised scale measures sensitivity to others' expressive behavior and ability to modify self-presentation, which are not directly related to social anxiety. The Concern for Appropriateness Scale measures cross-situational variability and attention to social comparison information, which are positively related to social anxiety. The revised self-monitoring scale and the Concern for Appropriateness Scale have acceptable internal consistency and are recommended for use. The findings suggest that Snyder's original five-component model is not valid, and the revised scales provide a more accurate measure of self-monitoring.The Self-Monitoring Scale by Snyder (1974) was found to have a stable factor structure that does not align with his five-component theoretical model. The authors describe sets of items that better reflect the theoretical structure and find that four of the five components are positively related to social anxiety. This challenges Snyder's theory and suggests a need for a narrower definition of self-monitoring. A revised 13-item Self-Monitoring Scale was developed, measuring sensitivity to others' expressive behavior and ability to modify self-presentation. A 20-item Concern for Appropriateness Scale was also introduced, measuring cross-situational variability and attention to social comparison information. Both scales have acceptable internal consistency and yield subscale scores. The theory of self-monitoring posits that individuals regulate self-presentation based on situational cues. However, recent studies failed to validate this theory, prompting a reevaluation of the scale. Factor analysis revealed three factors: acting ability, extraversion, and other-directedness, which do not align with Snyder's five components. The scale's factors correlate differently with other variables, indicating a mismatch between the scale and the construct. Study 1 examined the relevance of extraversion for self-monitoring and found that four items load together to define an extraversion factor. Study 2 developed five sets of items for each component of self-monitoring, resulting in a revised scale with four factors: cross-situational variability, acting ability, ability to modify self-presentation, and concern for appropriateness. Study 3 further refined the scale, leading to a 28-item version with four factors. Study 4 found that the revised scale better aligns with the theoretical structure and has higher internal consistency. The revised scale measures sensitivity to others' expressive behavior and ability to modify self-presentation, which are not directly related to social anxiety. The Concern for Appropriateness Scale measures cross-situational variability and attention to social comparison information, which are positively related to social anxiety. The revised self-monitoring scale and the Concern for Appropriateness Scale have acceptable internal consistency and are recommended for use. The findings suggest that Snyder's original five-component model is not valid, and the revised scales provide a more accurate measure of self-monitoring.