During the task estimation activity of a Sprint Planning meeting, the role that is typically not directly involved is the "Product Owner" (Option 4).
The key roles involved in Sprint Planning and task estimation are typically:
Developers: These team members are responsible for breaking down user stories into tasks and estimating the effort required to complete them.
Testers: Testers are part of the development team and are involved in task estimation, particularly when estimating testing-related tasks.
Scrum Master: The Scrum Master facilitates the Sprint Planning meeting and ensures that the Scrum process is followed but doesn't usually participate in task estimation.
The Product Owner's primary involvement is in providing clarity on user story requirements and prioritization. They may offer insights during the Sprint Planning meeting but are not directly involved in task estimation, as this is primarily a responsibility of the development team.
