A is related to B and C. How do I show that B and C might, by this context, be related as well?Example:Here are a few headlines about a recent Broadway play: David Mamet's Glengarry Glen Ross, Starring Al Pacino, Opens on BroadwayAl Pacino in 'Glengarry Glen Ross': What did the critics think?Al Pacino earns lackluster reviews for Broadway turnTheater Review: Glengarry Glen Ross Is Selling Its Stars HardGlengarry Glen Ross; Hey, Who Killed the Klieg Lights?Problem:Running a fuzzy-string match over these records will establish some relationships, but not others, even though a human reader could pick them out from context in much larger datasets.  How do I find the relationship that suggests #3 is related to #4? Both of them can be easily connected to #1, but not to each other. Is there a (Googlable) name for this kind of data or structure? What kind of algorithm am I looking for?Goal:Given 1,000 headlines, a system that automatically suggests that these 5 items are all probably about the same thing.To be honest, it's been so long since I've programmed I'm at a loss how to properly articulate this problem. (I don't know what I don't know, if that makes sense). This is a personal project and I'm writing it in Python. Thanks in advance for any help, advice, and pointers! 
How do I express subtle relationships in my data?
algorithms;python;data structures
It's called cluster analysis, which is basically grouping objects into clusters with similar properties.  It's a huge topic, but that should give you a place to start.