  We revisit a possible scale-dependence of local-type primordial
non-Gaussianities induced by super-horizon evolution of scalar field
perturbations. We develop the formulation based on $\delta N$ formalism and
derive the generalized form of the local-type bispectrum and also trispectrum
which allows us to implement the scale-dependence and suitably compare model
prediction with observational data. We propose simple but phenomenologically
meaningful expressions, which encompass the information of a wide range of
physically motivated models. We also formulate large-scale power spectrum and
bispectrum of biased objects in the presence of the scale-dependent primordial
non-Gaussianities. We perform the Fisher analysis for future galaxy surveys and
give the projected constraints on the parameters of the generalized local-form
of primordial non-Gaussianities.
