  We present results from a comparative study of light curves of Cepheid and RR
Lyrae stars in the Galaxy and the Magellanic Clouds with their theoretical
models generated from the stellar pulsation codes. Fourier decomposition method
is used to analyse the theoretical and the observed light curves at multiple
wavelengths. In case of RR Lyrae stars, the amplitude and Fourier parameters
from the models are consistent with observations in most period bins except for
low metal-abundances ($Z<0.004$). In case of Cepheid variables, we observe a
greater offset between models and observations for both the amplitude and
Fourier parameters. The theoretical amplitude parameters are typically larger
than those from observations, except close to the period of $10$ days. We find
that these discrepancies between models and observations can be reduced if a
higher convective efficiency is adopted in the pulsation codes. Our results
suggest that a quantitative comparison of light curve structure is very useful
to provide constraints for the input physics to the stellar pulsation models.
