  We discuss the ``angular size - redshift'' relation for compact radio sources
distributed over a wide range of redshifts 0.01 < z < 4.73. Our study is based
on a sample of 330 5 GHz VLBI contour maps taken from the literature. Unlike
extended source samples, the ``angular size - redshift'' relation for compact
radio sources appears consistent with the predictions of standard Friedmann
world models with q_o ~ 0.5 without the need to consider evolutionary or
selection effects due to a ``linear size -- luminosity'' dependence. By
confining our analysis to sources having a spectral index, -0.38 < alpha <
0.18, and a total radio luminosity greater than 10^{26} W/Hz, we are able to
restrict the dispersion in the ``angular size -- redshift'' relation. The best
fitting regression analysis in the framework of the Friedmann-Robertson-Walker
model gives the value of the deceleration parameter q_o = 0.21 +- 0.30 if there
are no evolutionary or selection effects due to a ``linear size --
luminosity'', ``linear size -- redshift'' or ``linear size -- spectral index''
dependence.
