COM 411

```{r setup, include=FALSE} knitr::opts_chunk$set(echo = F) knitr::opts_knit$set(root.dir = './') source("resources/preamble.R") f <- function (x) {formatC(x, format="d", big.mark=',')} bold <- function(x) {paste('{\\textbf{',x,'}}', sep ='')} gray <- function(x) {paste('{\\textcolor{gray}{',x,'}}', sep ='')} wrapify <- function (x) {paste("{", x, "}", sep="")} p <- function (x) {formatC(x, format='f', digits=1, big.mark=',')} library(igraph) ```## Today's Dad Joke I accidentally swallowed a bunch of scrabble tiles. My next trip to the bathroom could spell disaster. ## Housekeeping > - Exam on Thursday! ## Last Class > - Only 9 people were here!

# Ego networks ## Sources of ego networks > - Surveys of individuals > - "Extraction" from complete network > - Usually one step from ego ## What can we measure about ego networks? > - Degree centrality (size) > - Density > - Groups > - Distance > - Homogeneity > - Homophily > - Composition ## How can we use ego network data? > - GSS data > - Changes over time > - Comparison by location > - Predicting individual outcomes > - Health > - Employment > - Happiness # Review ## Network representations > - Matrices > - Edgelists > - Directed/undirected > - Ego > - Bipartite / 2 mode > - Projections ## R > - Vectors > - Matrices > - Data frames > - Creating an igraph network object > - Viewing/setting attributes on nodes/edges ## Network measures >- Degree Centrality >- Closeness Centrality >- Betweenness Centrality >- Eigenvector Centrality >- Density >- Centralization ## Homework > - Study! :)