\begin{table}%T1 \caption{\label{tb:FOFparam}Values of free parameters used for creating mock and observed group catalogues.} %\centerline { \begin{tabular}{lllrrllll} \hline \hline\\[-3.2mm] Authors & Sample & $m_{\rm lim}$ & $D_{0}$ & $V_{0}$ & $\frac{\delta \rho}{\rho}$ & $\alpha$ & $M^{*}$ & $\phi^{*}$\\[-3.2mm]\\ \hline This paper & Mock1 & 13.2 & 0.64 & 400 & 19.8 & $-1.02$ & $-19.06$ & 0.0277\\ This paper & Mock2 & 14.0 & 0.37 & 200 & 68.0 & $-1.15$ & $-19.84$ & 0.0172\\ Huchra \& Geller (1982) & HG82 & 13.2 & 0.64 & 400 & 20 & $-1.02$ & $-19.06$ & 0.0277\\ Ramella et al. (2002) & UZC-SSRS2 & 15.5 & 0.25 & 350 & 80 & $-1.1~(-1.2)$ & $-19.1~(-19.73)$ & 0.04 (0.013)\\ Eke et al. (2004) & 2dFGRS & 19.45 & 0.13 & 143 & $-$ & $-$ & $-$ & $-$\\ \cite{Goto:2005p517} & SDSS-DR2 & 17.77 & 1.5 & 1000 & $-$ & $-$ & $-$ & $-$\\ Merch\'an \& Zandivarez (2005) & SDSS-DR3 & 17.77 & $-$ & 200 & 80 & $-1.05$ & $-20.44$ & $-$\\ Berlind et al. (2006) & SDSS-DR3 & 17.5 & 0.14 & 75 & $-$ & $-$ & $-$ & $-$\\ Tago et al. (2006) & 2dFGRS & 19.45 & 0.25 & 200 & $-$ & $-1.21$ & $-19.66$ & $-$\\ Tago et al. (2008) & SDSS-DR5 & 17.77 & 0.25 & 250 & $-$ & $-$ & $-$ & $-$\\ \hline \end{tabular}} \medskip \par Columns: The group catalogue used, $m_{\rm lim}$ is the apparent magnitude limit of the search ($B$-band for mock catalogues, $r$-band for the SDSS and $b_{j}$ for the 2dF, note however that different redshift limits have been applied in individual papers), $D_{0}$ is the projected separation in $h^{-1}$~Mpc chosen at some fiducial redshift, $V_{0}$ is the velocity difference in~km~s$^{-1}$, $\frac{\delta \rho}{\rho}$ is the density enhancement and $\alpha$, $M^{*}$, and $\phi^{*}$ parametrize the \citet{Schechter:1976p592} function. The Schechter parameters for the Mock2 sample are derived from the Millennium Galaxy Catalogue by \cite{Driver:2007p587}. The Schechter parameters for Ramella et al. (2002) refer to the CfA (SSRS2) groups. \end{table}