Not to view all tasks by all the technicians

Not to view all tasks by all the technicians

Dear all

When a technician adds a new task in his/her home tab in service desk the task can be viewed by all the other technicians when they click on "Show all" .
I want to know Is there any way to make some tasks private which can be viewed by the technician who has created the task?

Thanks in Advance
Negin