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In this paper, we use the Cosmokinematics approach to study the acceleratedexpansion of the Universe. This is a model independent approach and dependsonly on the assumption that the Universe is homogeneous and isotropic and isdescribed by the FRW metric. We parametrize the deceleration parameter, $q(z)$,to constrain the transition redshift ($z_t$) at which the expansion of theUniverse goes from a decelerating to an accelerating phase. We use threedifferent parametrizations of $q(z)$ namely,$q_\I(z)=q_{\textnormal{\tiny\textsc{1}}}+q_{\textnormal{\tiny\textsc{2}}}z$,$q_\II (z) = q_\3 + q_\4 \ln (1 + z)$ and$q_\III(z)=\frac{1}{2}+\frac{q_{\textnormal{\tiny\textsc{5}}}}{(1+z)^2}$. Ajoint analysis of the age of galaxies, strong lensing and supernovae Ia dataindicates that the transition redshift is less than unity i.e. $z_t<1$. We alsouse a nonparametric approach (LOESS+SIMEX) to constrain $z_t$. This too gives$z_t<1$ which is consistent with the value obtained by the parametric approach.

Transition Redshift: New constraints from parametric and nonparametric methods