A metric is the measurement of a given aspect or characteristic of performance. This is a very high-level term used to describe almost every measurement in analyzing website traffic and marketing campaign performance. It usually needs to be calculated and expressed within a context of time to give a solid frame of reference such as revenue earned in the past 12 months, or percentage of visitors converted to customers in the past month.
Some metrics are the direct measure of some type of performance such as number of units sold, visitors or orders. I usually refer to these as prime, basic or simple metrics, as they can not be broken down any further into any metrics used to create them. However, to develop a clear picture of performance one would have to consider many such basic metrics which most of the time cause inefficiency and inaccuracy of analysis due to the large number of loosely-related metrics.
in such cases, calculated metrics come to ones help by abbreviating the data to be analyzed. These are obtained by combining simple metrics using mathematical formulae to represent a more actionable piece of data. For instance, instead of reviewing the number product views and number of cart addition separately, one can review the product view to cart addition conversion metric which is represented as the percentage of product views that resulted in cart additions.
More to come later.