10 Adham Beykikhoshk, Ognjen Arandjelovi´c, Dinh Phung, Svetha Venkatesh, and Terry Caelli Original tweet: Pre-processed result: Original tweet: Pre-processed result: 4.2 Methods and results 4.2.1 Power law: Zipf’s distribution 101 autism: Genetic analysis of individuals with autism finds gene deletions - Using powerful genetic sequencing. http://is.gd/UhprQK 101 autism genet analysi individu autism find gene delet use power genet sequenc url #Apple #Censorship & Dr. Brian Hooker Interview exposing CDC Cover-up of the Vaccine & Autism Link on .@rediceradio http://youtu.be/19uvPtg6SPI appl censorship dr brian hooker interview expos cdc cover vaccin autism link atus url In this section we describe a series of experiments aimed at discovering the properties of the collected data. We start with a generic quantitative linguistic analysis and proceed with increasingly domain-specific considerations which examine tweet content and the potential differentiation between the ASD-related and the control corpora. The first experiment we conducted was set to find out if tweets, both in the ASD corpus as well as the control group, obey the so-called Zipf’s law. In its general form, this empirical law posits that the frequency P$_{i}$ of an ‘event’ is approximately a power function of its fre- quency rank r$_{i}$ , i.e. P$_{i}$ ∝ r a i where r$_{i}$ is the rank ( r$_{i}$ = 1 , . . . ) of the event when events are ordered by their frequency of occurrence from high to low and a < − 1 . Zipf’s distribution can be seen to be a type of a power law probability distribution. This statistical regularity is observed in a variety of domains ranging from deadly quarrel [36] and wealth distribution