What is the best technique to represent similarily among different methods? Lets say I have 3 different methods. I am trying to find the best technique to represent similarities (or differences) among these methods. 

One way I thought of is to create a table and create my own correlation methodology (e.g., high, medium, and low). However, I am not sure if this is the best way to do it. 



Here is the corresponding LaTeX code I created (just in case):

\documentclass{article}
\usepackage{booktabs}

\begin{document}
\begin{table}
    \centering
\begin{tabular}{llll}
    \toprule
             &amp; Method 1 &amp; Method 2 &amp; Method 3 \\
    Method 1 &amp; High &amp; High  &amp; Low \\
    Method 2 &amp; Medium &amp; Low &amp; Low \\
    Method 3 &amp; Low &amp; Low  &amp; Low \\
    \bottomrule
\end{tabular}
\caption{Level of correlation among different methods}
\end{table}
\end{document}
I assume that the high, low and medium corresponds to some analytical values and are dependent on various factors. So how about to assign some values to all constraints and so to this high, low and mediums also. Then finally show as an shaded matrix plot e.g.,