\chapter{Results}

%TODO some text here
This section shows the results of the experiments described in section 3 on the data sets described in section 4. In the following diagrams, the blue line states the (a) average sentiment of the answers to questions from new contributors/(b) average vote score of questions from new contributors and (c) the number of 1st and follow up questions of new contributors. These lines also have numbers attached to it at every datapoint and shows (a) the number of answers that formed the sentiment average/(b) the number of questions that formed the average vote score. The orange line shows ITS analysis as a 3-segment line.


% pvalues ... 
% maybe average data points per month


%TODO write some text to each result
\pagebreak
\section{StackOverflow.com}
StackOverflow shows a very slight decrease in average sentiment of time before the change had been introduced. When the change occured the average sentiment jumped up. After the change the sentiments reached higher levels and kept rising. The average vote score rose right before and stay fairly constant after the change. this indicates that the vote score was not affected by the change. However, the number of questions from new contributors increased after the change while prir to the change the was fairly constant. The number of follow up questions from new contributors were declinied prior to the change and rose after the change.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../stackoverflow.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on StackOverflow.com}
  \label{stackoverflow_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../stackoverflow.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on StackOverflow.com}
  \label{stackoverflow_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../stackoverflow.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on StackOverflow.com}
  \label{stackoverflow_questionsits}
 \end{subfigure}
\end{figure}
% sentiment falling prior to change
% jump upward at the change
% sentiments rising after change

\section{math.stackexchange.com} 
The math.stackexchange.com community shows a decrease in average sentiments, vote score, and number of questions prior to the change. The measurements make a small jump upward when the change is introduced, however, they continue their downward trend after the introduction of the change. Only the number of follow up questions stabilized and began increasing after the change.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../math.stackexchange.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on math.stackexchange.com}
  \label{math_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../math.stackexchange.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on math.stackexchange.com}
  \label{math_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../math.stackexchange.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on math.stackexchange.com}
  \label{math_questionsits}
 \end{subfigure}
\end{figure}
% sentiments falling prior to the change
% sentiments falling faster than before the change

\section{MathOverflow.net}
MathOverflow shows a constant regresssion before the change, however, average sentiments are low at about 10 months before the change and spiked high directly before the change. When the change is introduced regression makes a small jump up and decreases thereafter. The votes score steadily increased prior to the change and then quickly returned to the level from 3 years before the change. The number of 1st questions are falling prior the change and stabilized thereafter. This data set is sparse compared to the other datasets. Also the vote scores are high compared to other datasets.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../mathoverflow.net/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on MathOverflow.net}
  \label{matho_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../mathoverflow.net/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on MathOverflow.net}
  \label{matho_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../mathoverflow.net/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on MathOverflow.net}
  \label{matho_questionsits}
 \end{subfigure}
\end{figure}
% senitments stable/constant prior to the change
% falling after the change

\section{AskUbuntu.com}
AskUbuntu saw a decrease in average sentiments prior to the change. After the introduction of the change the regression dipped but sentiments keep rising drastically since then. The vote score has a huge range of values prior and after the change, hoewever the graph indicates the the vote score is declining after the change. The number of 1st questions slightly decreased prior the change and started rising after the change.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../askubuntu.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on AskUbuntu.com}
  \label{ubuntu_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../askubuntu.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on AskUbuntu.com}
  \label{ubuntu_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../askubuntu.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on AskUbuntu.com}
  \label{ubuntu_questionsits}
 \end{subfigure}
\end{figure}
%senitments have gradually fallen prior to the change
% sentiments increased after the change
%maybe: sentiments did not change drastically as seen in maths communities

\section{ServerFault.com}
ServerFault shows gradually rising average sentiments prior to the change. At the time of the change the regession makes a jump upward and the average sentiment decrease slowly afterward. The vote score fell prior to the change, made a huge jump upward and quickly returned to the levels just prior to the change. The number of 1st questions, however, saw a drastic change. Prio to the change the number of 1st questions decreased steadily, while after the change the numbers increase at the same pace as they were falling prior to the change. The number of follow up questions also saw the same course direction, falling prior and raising after the change.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../serverfault.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on ServerFault.com}
  \label{fault_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../serverfault.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on ServerFault.com}
  \label{fault_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../serverfault.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on ServerFault.com}
  \label{fault_questionsits}
 \end{subfigure}
\end{figure}
%sentiments fairly stable before and after the change
% small jump in avg sentiments at change date

\section{SuperUser.com}
SuperUser shows only sightly decreasing average sentiment and vote score up to the change. At the change time the regressions take a dip down and the regression shows a downward trend after the change. Indeed the average sentiments and vote score dipped considerably when the change is introducted. The average sentiment recovers about 13 months later, while the vote score does not recover as well. The number of 1st questions are decrasing prior to the change and then went through the roof indicating a huge wave of new users. This drastic influx of new users may explain the crash of the average sentiment and vote score that occured at the same time. Data available in the future will show if the recovery is persistent.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../superuser.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on SuperUser.com}
  \label{super_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../superuser.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on SuperUser.com}
  \label{super_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../superuser.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on SuperUser.com}
  \label{super_questionsits}
 \end{subfigure}
\end{figure}
%sentiments fairly stable until the change date
%after change sentiments took a samll dive 
% recovery after after 13 months to not quite the previous levels

\section{electronics.stackexchange.com}
On electronics.stackexchange.com the average sentiment and votes decrease continuously prior to the change. At the change date the regressions makes a little jump upward but the trend from before the change continues afterward. Similarly to SuperUser, the average sentiment recover at about 12 months after the change is introduced and future data will be necessary to determine if the recovery is persistent. The number of 1st questions rose continuously prior the the change and decreased thereafter. The number of follow up questions fell slightly prior to the change and stabilized afterward.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../electronics.stackexchange.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on electronics.stackexchange.com}
  \label{ele_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../electronics.stackexchange.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on electronics.stackexchange.com}
  \label{ele_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../electronics.stackexchange.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on electronics.stackexchange.com}
  \label{ele_questionsits}
 \end{subfigure}
\end{figure}
%sentiments were falling continuously before and after the change
% recovery started after 12 month after the change
% more data in the future will be required to determine if upward trend in the end continues

\section{stats.stackexchange.com}
On stats.stackexchange.com the average sentiment is steadily decreasing prior to the change. The regression dips when the change is introduced. However, the average sentiment after the change indicate a slight upward trend. The vote score also decreased prior to the change but does not recover afterward. However, the number of 1st questions and follow up questions are raising prior to the change and increase even faster after the change. 
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../stats.stackexchange.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on stats.stackexchange.com}
  \label{stats_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../stats.stackexchange.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on stats.stackexchange.com}
  \label{stats_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../stats.stackexchange.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on stats.stackexchange.com}
  \label{stats_questionsits}
 \end{subfigure}
\end{figure}
% sentiments steadily decreasing prior to the change
% dip in avg sentiment at the change date
% sight upward trend after the change

\section{tex.stackexchange.com}
On tex.stackexchange.com the average sentiment is low compared to the other investigated data sets. Prior to the change the average sentiment only slightly decreases. When the change is introduced the regression takes a dip down and after the change the average sentiment increases drastically. Future data will be required to see if this upward trend continues or evens out. In stark contrast, the vote score shows a downward trend, although there is a short window around the change date where vote scores are higher compared to before and after change. The number of 1st questions have downward trend before the change and an upward trend afterward. The downward trend of the number of follow up questions is uninterrupted by the change.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../tex.stackexchange.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on tex.stackexchange.com}
  \label{tex_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../tex.stackexchange.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on tex.stackexchange.com}
  \label{tex_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../tex.stackexchange.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on tex.stackexchange.com}
  \label{tex_questionsits}
 \end{subfigure}
\end{figure}
%avg sentiment fairly low compared to the other investigated communities
% avg sentiment slowly decreasing prior to the change
% large dips in avg snetiment after the change
% trend after change strongly upward

\section{unix.stackexchange.com}
On unix.stackexchange.com the average sentiment is decreasing prior to the change. When the change is introduced the regression take a small dip down, however, the average sentiment increases fast after the change. The vote score shows continuous downward trend. The number of 1st and follow up questions are falling slightly prio to the change and increase afterward.
\begin{figure}[H]
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../unix.stackexchange.com/output/its/average_sentiments-i1.png}
  \caption{An interrupted time series analysis of the sentiments of answer to questions created by new contributors on unix.stackexchange.com}
  \label{unix_its}
 \end{subfigure}
 \begin{subfigure}[t]{0.5\textwidth}
  \includegraphics[scale=0.37]{../unix.stackexchange.com/output/votesits/average_votes-i1.png}
  \caption{An interrupted time series analysis of the vote score of questions created by new contributors on unix.stackexchange.com}
  \label{unix_votesits}
 \end{subfigure}\\
 \begin{subfigure}[c]{0.5\textwidth}
  \includegraphics[scale=0.37]{../unix.stackexchange.com/output/questionits/average_questions-i1.png}
  \caption{An interrupted time series analysis of the number of questions created by new contributors on unix.stackexchange.com}
  \label{unix_questionsits}
 \end{subfigure}
\end{figure}
%sentiments decreasing prior to the change
%snetiments rising after the change
% little jump upwards at change date



