1. An automatic, computer implemented, method for estimating the probability of interaction (PTI) between a plurality of avatars sharing the same online virtual environment; each said avatar being associated with a different member of an online social network, said online social network existing independently of said online virtual environment, and comprising non-anonymous real-world data from non-anonymous real-world users; said online virtual environment being a graphical virtual world environment; said method comprising: using at least one computer to obtain non-anonymous real-world user data from said social network; obtaining an online virtual environment comprising a virtual world populated with a plurality of avatars, wherein each said avatar is associated with a different member of said online social network, and each avatar has linked social network comprising at least some non-anonymous real-world user data from said social network; wherein said avatars comprise graphical representations of said users, and wherein said avatars are capable of user directed movement in said virtual world; using said at least one computer to determine a time history of virtual world interactions between said members and computing at least one virtual world PTI predictor value; wherein said at least one virtual world PTI predictor value is a virtual world PTI predictor value consisting of virtual world interactions between members and other in said online virtual world environment over a defined time interval, and in which determining the time history of virtual world interactions between said members and interactions between members and other members is done by computing a plurality of different virtual world PTI predictor values over a range of different time intervals; using said at least one computer and information obtained from said online social network to determine a degree of social connection similarity between said members and generating a social connection PTI predictor value; using said at least one computer to determine an overall PTI using an aggregate function of said at least one virtual world PTI predictor value and said social connection PTI predictor value; using said overall PTI to control said online virtual environment; wherein controlling said online environment further comprises distributing said avatars in a parent virtual room in which the number of avatars exceeds an upper desirable limit, into first and second child virtual rooms in which the number of avatars does not exceed the upper desirable limit, said method comprising: determining which said avatars and corresponding members are presently engaged in conversations, each conversation comprising one or more avatars, thereby creating a total conversation set and repeating the steps of: 1: performing a selection process by selecting pairs of conversations C 1 and C 2 from said total conversation set in which a summation function of the overall PTI values between the members of C 1 and members of C 2 are lowest, putting the C 1 members into the first child virtual room, putting the C 2 members into the second child room, and then eliminating this selected pair of conversations from the total conversation set; 2: repeating said selection process using the remaining total conversation set, thus selecting conversations C 1 next and C 2 next, further determining which of said first or second child room to place members of C 1 next and members of C 2 next by determining the summation function of the overall PTI values between the members of the selected conversations and the members of the child rooms, and assigning the respective selected conversation members to the respective child room that has the maximum summation function of the overall PTI values.