deletions | additions       diff --git a/section_Data_analysis_and_results__.tex b/section_Data_analysis_and_results__.tex  index 4e12cba..420e946 100644  --- a/section_Data_analysis_and_results__.tex  +++ b/section_Data_analysis_and_results__.tex 
...
To make sure the tests measured general cognitive ability as desired, we carried out factor analysis to see whether all the loadings were positive. We found...  \subsection{Average items correct by age and class}  Shown on figure~\ref{fig:age_score} Fig.~\ref{fig:age_score}  is the plotted scores by the pupils age. The different grades are colorcoded. \subsection{Error analysis}  To understand how students got the items wrong, we analyzed...