  The $N^*(1535)S_{11}$ coupling strength to the $K^+\Lambda$ channel,
$g_{N^*(1535)\Lambda K^+}$, is extracted from the latest and largest
$K^+\Lambda$ photoproduction database by using an isobar model. It is found
that the coupling is small. In term of the coupling ratio the best result is
$R\equiv |g_{N^*(1535)\Lambda K^+}/g_{N^*(1535)\eta p}|=0.460\pm 0.172$, much
smaller than that obtained from the isobar analysis of the $J/\psi$ decays,
i.e., $1.3\pm 0.3$, but consistent with the results of the unitary chiral
approach of the same decay processes as well as the partial wave analysis of
kaon photoproduction, i.e., $R=0.5\sim 0.7$. The different results of $R$ found
here and in literature to date suggest that a more solid definition of the
coupling constant, especially in the case of $N^*(1535)S_{11}$ state, is
urgently required, before a fair comparison can be made.

Nuclear Theory;High Energy Physics - Phenomenology;Nuclear Experiment