An index:

a. combines two or more metrics into a single indicator
b. is complex to define, usually involves a calculation and is often in the form of a ratio
c. is easily defined with no calculations and with simple dimensions
d. is any quantitative output of an activity or process

Lance is a member of the professional organization iceaa. he always attends its annual conferences because it provides a great opportunity for with members of the same profession. in addition to the conference, iceaa organizes for members who are seeking better employment opportunities.