| isolation_index {webtrackR} | R Documentation |
Isolation Index
Description
Given two groups (A and B) of individuals, the isolation index captures the extent to which group A disproportionately visit websites whose other visitors are also members of group A.
Usage
isolation_index(grp_a, grp_b, adjusted = FALSE)
Arguments
grp_a |
vector (usually corresponds to a column in a webtrack data frame) indicating the number of individuals of group A using a website |
grp_b |
vector (usually corresponds to a column in a webtrack data frame) indicating the number of individuals of group B using a website |
adjusted |
logical. should the index be adjusted (defaults to FALSE) |
Details
a value of 1 indicates that the websites visited by group A and group B do not overlap. A value of 0 means both visit exactly the same websites
Value
numeric value between 0 and 1. 0 indicates no isolation and 1 perfect isolation
References
Cutler, David M., Edward L. Glaeser, and Jacob L. Vigdor. "The rise and decline of the American ghetto." Journal of political economy 107.3 (1999): 455-506. Gentzkow, Matthew, and Jesse M. Shapiro. "Ideological segregation online and offline." The Quarterly Journal of Economics 126.4 (2011): 1799-1839.
Examples
# perfect isolation
grp_a <- c(5, 5, 0, 0)
grp_b <- c(0, 0, 5, 5)
isolation_index(grp_a, grp_b)
# perfect overlap
grp_a <- c(5, 5, 5, 5)
grp_b <- c(5, 5, 5, 5)
isolation_index(grp_a, grp_b)