  We determine the small-scale structure for a large sample of Compact Steep
Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources and a sample of
larger radio sources at 327 MHz using the technique of Inter-Planetary
Scintillation (IPS) with the Ooty Radio Telescope. Our observations provide
structural information on angular scales ranging from about 50 to a few hundred
milliarcsec. We estimate the size and flux density of the scintillating
components from the IPS observations. The fraction of flux density of the
hotspots estimated from both the IPS observations as well as from
interferometric observations for larger sources from the literature exhibits no
significant dependence on either the radio luminosity or linear size for the
high-luminosity sources. We examine the collimation of radio jets using the
sizes of hotspots from both IPS and interferometric observations. The hotspot
sizes do not exhibit a significant dependence on the overall linear size for
the larger sources, although the CSS and GPS sources were earlier found to
evolve in a self-similar way. The IPS observations show evidence of
larger-scale structures compared to the known VLBI-scale structures in 8 CSS
and GPS radio sources. We discuss the origin of these structures. We also
examine the spectra of compact components in GPS sources using both IPS and
interferometric measurements, and attempt to distinguish between different
processes for explaining their low-frequency spectra.
