﻿[Script Info] Title: [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,0:00:00.00,0:00:05.00,Default,,0000,0000,0000,,One of the things we'd like able to do is to compute statistics on lists. Dialogue: 0,0:00:05.00,0:00:10.00,Default,,0000,0000,0000,,Imagine that we've got a set of n nodes and we've got L, which is a list of values-- Dialogue: 0,0:00:10.00,0:00:16.00,Default,,0000,0000,0000,,one for each of the nodes in the network and we want to compute statistics. Dialogue: 0,0:00:16.00,0:00:21.00,Default,,0000,0000,0000,,What are statistics? Astatistic is actually quite a simple idea. Dialogue: 0,0:00:21.00,0:00:24.00,Default,,0000,0000,0000,,It's just a number that summarizes a list of numbers. Dialogue: 0,0:00:24.00,0:00:28.00,Default,,0000,0000,0000,,If we have a list L--say a list of the centrality scores. Dialogue: 0,0:00:28.00,0:00:33.00,Default,,0000,0000,0000,,There's lots of different statistics that we can imagine that would summarized Dialogue: 0,0:00:33.00,0:00:37.00,Default,,0000,0000,0000,,these list of numbers--for example, how many numbers are in the list. Dialogue: 0,0:00:37.00,0:00:42.00,Default,,0000,0000,0000,,What's the largest number in the list? What's the total of all the scores in the list? Dialogue: 0,0:00:42.00,0:00:47.00,Default,,0000,0000,0000,,How many scores are in the list that are between 2 and 3 inclusive? Dialogue: 0,0:00:47.00,0:00:52.00,Default,,0000,0000,0000,,These are all different statistics and some of these are may be more useful than others Dialogue: 0,0:00:52.00,0:00:55.00,Default,,0000,0000,0000,,but there's lots of different statistics that we might want to compute. Dialogue: 0,0:00:55.00,0:01:00.00,Default,,0000,0000,0000,,In general when you're doing an analysis of large structures like social networks, Dialogue: 0,0:01:00.00,0:01:04.00,Default,,0000,0000,0000,,we need some way of summarizing this large amount of data--you can't just present the data Dialogue: 0,0:01:04.00,0:01:09.00,Default,,0000,0000,0000,,in the raw form--it's too much for people to think of all at once. Dialogue: 0,0:01:09.00,0:01:14.00,Default,,0000,0000,0000,,Statistics and computing statistics ends up being a really important operation.