1.4 ) \; \% &  & MARK-III \\[0.3cm] 
(10.5 \pm 3.9 \pm 1.3 ) \; \% & & CLEO-II \end{array} \right. \nonumber\end{aligned}$$

To translate these results into the values of ratio $R$, pole dominance is assumed for the $q^{2}-$dependence of the form factors for the $\pi e \nu_{e} (K e \nu_{e})$ decay with the mass of the vector resonance given by the mass of the $D^{*}(D^{*}_{s})$ meson : $$\begin{aligned}
R & = & \left\{\begin{array}{lll} 
(1.29 \pm 0.21\pm 0.11 ) & &  MARK-III \\[0.3cm] (1.01 \pm 0.20 \pm 0.07 ) 
& &  CLEO-II \end{array} \right. \nonumber\end{aligned}$$ Given the size of these errors, it is premature to claim that a value less than unity is ruled out.

In an analysis of two body hadronic decays, $D^+\rightarrow\pi^+\pi^0$ and $D^0\rightarrow  K^+\pi^-$ Chau et.al. [@Cea] calculated the ratio $R$ and found that relative magnitude of the form factors should be such that $f^{D\rightarrow  \pi}_{+}(0)>f^{D\rightarrow K}_{+}(0)$ in order to be consistent with the pattern of $SU(3)$ breaking. However, this calculation relies on the large-$N_{c}$ factorization approach in addition to the pole dominance assumption for the $q^{2}-$dependences of the form factors. They also neglect the final state interaction effects. These assumptions have recently been questioned by Kamal 