The spectroscopic-factor amplitudes for the triton-cluster transfer are used in distorted wave born approximation (DWBA) analyses for the first six (12)C states, up to E(x)=17.76 MeV, in the reaction (15)N(p,alpha) for E(p)=9.09-43.7 MeV. Agreements are obtained for most (12)C states between the theoretically predicted spectroscopic factors (S) and both of experimental and theoretical forward integrated cross-section values (at E(p) approximately 43.7 MeV) and their sequence states with the same nuclear parameters. The theoretical spectroscopic factors failed to predict the transition strengths for the two (12)C states at 7.6542 and 17.76 MeV, while the DWBA predictions failed to reproduce the strengths of the three (12)C states at 7.6542, 14.083 and 17.76 MeV. This is probably, in the first case, due to the inclusion of other direct mechanisms and (or) to the multi-step processes in their mechanism, while for the second case, it is may be due to either the angular momentum mismatching effect or the choice of the optical parameters. The agreement between theoretical and experimental data for the first six investigated (12)C states indicate the success of the Cohen-Kurath wave-functions itself and their accuracy. They also indicate the success of the model of calculations of spectroscopic factors.