\subsubsection{Ranking}
\label{3_ranks}

\begin{subfigs}{3_ranks}{%
        Experiment \#1. Boxplots of the ranking (lower is better) of each visual hand rendering
        %
        and pairwise Wilcoxon signed-rank tests with Holm-Bonferroni adjustment:
        %
        ** is \p[<]{0.01} and * is \p[<]{0.05}.
    }
    \subfig[0.24]{3-Ranks-Push}[Push Task]
    \subfig[0.24]{3-Ranks-Grasp}[Grasp Task]
\end{subfigs}

\figref{3_ranks} shows the ranking of each visual hand rendering for the Push and Grasp tasks.
%
Friedman tests indicated that both ranking had statistically significant differences (\p[<]{0.001}).
%
Pairwise Wilcoxon signed-rank tests with Holm-Bonferroni adjustment were then used on both ranking results (see \secref{3_metrics}):

\begin{itemize}
    \item \textit{Push Ranking}: Occlusion was ranked lower than Contour (\p{0.005}), Skeleton (\p{0.02}), and Mesh (\p{0.03});
          %
          Tips was ranked lower than Skeleton (\p{0.02}).
          %
          This good ranking of the Skeleton rendering for the Push task is consistent with the Push trial results.
    \item \textit{Grasp Ranking}: Occlusion was ranked lower than Contour (\p{0.001}), Skeleton (\p{0.001}), and Mesh (\p{0.007});
          %
          No Hand was ranked lower than Skeleton (\p{0.04}).
          %
          A complete visual hand rendering seemed to be preferred over no visual hand rendering when grasping.
\end{itemize}