Introspection is a reflective exercise that looks within ourselves to find the answers. Here's the danger of introspection - I will end up doing what is right in my own eyes. This is due to the fundamental premise that introspection does not include the counsel and advice from others (especially advice I do not like to hear but I know it's true!).
Self-Discovery, on the other hand, is a reflective experience which incorporates the elements of feedback, assessment and validation which is role-focused. Self-Discovery is about finding out how I can be a better husband, father, friend, etc. And the outcome of my reflective process is validated not by my own standards but by the standards of my audience - my wife, my children, my colleagues, etc.
It is important that as we pause during this time of the year to take stock, be careful not to do in isolation of your life roles. Life is measured more by the effectiveness of your roles rather than the measurement of bottom-line results.