Vague definitional descriptors of the Coaching Alliance Common Factor measurement threaten construct validity in coaching research. Further, differing coach and client perceptions of the helping relationship, and coaching and therapeutic client dissimilarities compound the risk. Ten clients representing a global leadership coaching practice identified and prioritized the most helpful Client Characteristics, Coach Qualities, and Client/Coach Relationship during the program. Following, the respondents operationally defined the prioritized descriptors during an interview. Client multi-dimensional meanings, descriptors unique to coaching, and the importance of relationship bonding separated from and related to the work findings in the case study reinforced research’s call for definitional clarification and a distinct coaching model and instrument.