Network analysis glossary
Ego networks
An ego network is the part of a network seen from one person: that person (the ego), everyone they are directly tied to (the alters), and the ties among those alters. It is how most personal network research is done, because it needs only one person's account rather than a whole group's.
Updated · Netgraf
How ego networks are collected
- Name generator: ask the ego to list people for a stated purpose, such as "who did you discuss important matters with in the last six months?"
- Name interpreter: for each alter, record attributes such as relationship type, how long known and how often in contact.
- Alter ties: ask whether each pair of alters knows each other. This is what turns a list into a network.
What it reveals
Two ego networks of the same size can be very different. If the alters all know each other (high clustering) the ego is embedded in one close group. If they fall into separate clusters that connect only through the ego, the ego is a broker spanning structural holes, which Burt links to faster promotion and better ideas.
Mapping one in Netgraf
Put the ego in the centre, add each alter with their role as the subtitle, draw a tie from the ego to every alter, and then draw the ties between alters. Colour the ties by kind (family, business, social) and the separate spheres of a life separate themselves on the map. The PayPal Mafia is effectively a set of overlapping ego networks around a handful of founders.