According to the Scrum Guide1, the Scrum Master is accountable for establishing Scrum as defined in the Scrum Guide. They do this by helping everyone understand Scrum theory and practice, both within the Scrum Team and the organization. The Scrum Master serves the Developers in several ways, including:
Coaching them in self-management and cross-functionality;
Helping them to create high-value products;
Removing impediments to their progress;
Facilitating Scrum events as requested or needed; and,
Coaching them in organizational environments in which Scrum is not yet fully adopted and understood.
The Scrum Master serves the Product Owner in several ways, including:
Helping find techniques for effective Product Goal definition and Product Backlog management;
Helping the Scrum Team understand the need for clear and concise Product Backlog items;
Helping establish empirical product planning for a complex environment; and,
Facilitating stakeholder collaboration as requested or needed.
The Scrum Master serves the organization in several ways, including:
Leading, training, and coaching the organization in its Scrum adoption;
Planning and advising Scrum implementations within the organization;
Helping employees and stakeholders understand and enact an empirical approach for complex work; and,
Removing barriers between stakeholders and Scrum Teams.
Therefore, two things that are true about the Scrum Master role are:
The Scrum Master teaches the Development Team to keep the Scrum meetings to their time-box, as they help everyone understand Scrum theory and practice.
The Scrum Master helps those outside the team interact with the Scrum Team, as they serve both the Product Owner and the organization.
The other options are not true about the Scrum Master role, as they imply that they have authority or responsibility over things that are not within their accountability.
References: Scrum Guide
