For an employee feedback system, what should be the design for a feedback master table in which user will post their feedback against a person on a single criteria

start with some paper, a pencil and a rubber (eraser for the Australiains amongst us)

try to identify the main entities (so that will be things like employees, comment types)
identify as many attributes of those entitites (eg their name,contact numbers, dates and times)

refine your design
be prepared to revisit what you have already done reworking and improving the design as you knwoledge of what you want to do expands, and as your knowledge of how you do it expands.

read the relevent refeences on things like normalisation, entity design and so on.

here's a couple of well reviewed references, but I'm sure there are more out there
Fundamentals of Relational Database Design -- r937.com
The Relational Data Model, Normalisation and effective Database Design

thanks ya.. i have done the initial design. But the problem is for an employee say jack all the members in his team will be entering feedback. For ex. the criteria is communication skill and the option are excellent, poor, satisfactory. For this, his all other team mates will be answering. how should i capture this in the database.

Practicing "safe" data retrieval are you? ;-)

what have you thought about so far?

Sorry,i couldnt understand tat..