  We have determined the transparency of the nuclear medium to kaons from
$A(e,e^{'} K^{+})$ measurements on $^{12}$C, $^{63}$Cu, and $^{197}$Au targets.
The measurements were performed at the Jefferson Laboratory and span a range in
four-momentum-transfer squared Q$^2$=1.1 -- 3.0 GeV$^2$. The nuclear
transparency was defined as the ratio of measured kaon electroproduction cross
sections with respect to deuterium, ($\sigma^{A}/\sigma^{D}$). We further
extracted the atomic number ($A$) dependence of the transparency as
parametrized by $T= (A/2)^{\alpha-1}$ and, within a simple model assumption,
the in-medium effective kaon-nucleon cross sections. The effective cross
sections extracted from the electroproduction data are found to be smaller than
the free cross sections determined from kaon-nucleon scattering experiments,
and the parameter $\alpha$ was found to be significantly larger than those
obtained from kaon-nucleus scattering. We have included similar comparisons
between pion- and proton-nucleon effective cross sections as determined from
electron scattering experiments, and pion-nucleus and proton-nucleus scattering
data.
