## Original tweet: 

101 autism: Genetic analysis of individuals with autism finds gene deletions - Using powerful genetic sequencing. http://is.gd/UhprQK 

## Pre-processed result: 

101 autism genet analysi individu autism find gene delet use power genet sequenc url 

## Original tweet: 

#Apple #Censorship & Dr. Brian Hooker Interview exposing CDC Cover-up of the Vaccine & Autism Link on .@rediceradio http://youtu.be/19uvPtg6SPI 

## Pre-processed result: 

appl censorship dr brian hooker interview expos cdc cover vaccin autism link atus url 

## 4.2 Methods and results 

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. 

## 4.2.1 Power law: Zipf’s distribution 

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 

