In this formula K equals the number of file folders, also called clusters; each folder holds a number of documents. We will use M to mean the number of documents that are in any one file folder. We will designate the file folder as i.

And this, Calli, is why we have jargon such as "Where K denotes the total number of clusters and m is the sum of all members in cluster i."

It took me more than twice as many words to get the point across, but that is totally unnecessary if the person reading the article understands the jargon. I spent many years as a writer who specialized in taking jargon and turning it into the language of the common folk, and there is a fine balance between being verbose and not getting the jargon simplified so the common folk can understand it at the first reading.

TEd