  Have been analyzed the latest experimental data for $\gamma + p \to K^{+} +
\Lambda$ reaction of $C_{x'}$ and $C_{z'}$ double polarizations. In theoretical
calculation, all of these observables can be classified into four Legendre
classes and represented by associated Legendre polynomial function itself
\cite{fasano92}. In this analysis we attempt to determine the best data model
for both observables. We use the bayesian technique to select the best model by
calculating the posterior probabilities and comparing the posterior among the
models. The posteriors probabilities for each data model are computed using a
Nested sampling integration. From this analysis we concluded that $C_{x'}$ and
$C_{z'}$ double polarizations require two and three order of associated
Legendre polynomials respectively to describe the data well. The extracted
coefficients of each observable will also be presented. It shows the structure
of baryon resonances qualitatively
