Canned response is a preset repository of questions or answers. This feature helps the users to fetch the questions from repository rather than to type them manually. Admin has the option to feed the questions in canned response as and when required.
This feature is denoted by the icon 
and is located just next to the spell checker icon in the Create Evaluation screen as shown-
Clicking Canned Response icon will open up a Canned Response window which is shown as follows-
The user can select the question based upon the set categories. When the question is selected from the screen, the pre-set answer gets visible on the message box located below in the window as shown-
For the selected question 1 in the box above in the screen, the relative answer is displayed in the message box below in the window.
Click 
button to add the answer in the Create Evaluation screen.
Also check on Canned Response for more information.
Video