Assume that there is no quasi-measurable cardinal smaller than $2^\omega$.
($\kappa$ is quasi measurable if there exists $\kappa $-additive ideal $\ci $
of subsets of $\kappa $ such that the Boolean algebra $P(\kappa)/\ci$ satisfies
c.c.c.) We show that for a c.c.c. $\sigma $-ideal I with a Borel base of
subsets of an uncountable Polish space, if $\cal A$ is a point-finite family of
subsets from I then there is an uncountable collection of pairwise disjoint
subfamilies of $\cal A$ whose union is completely nonmeasurable i.e.
In this paper we invastigate the notion of generalized (I,J) - Luzin set.
This notion generalize the standard notion of Luzin set and Sierpinski set. We
find set theoretical conditions which imply the existence of generalized (I,J)
- Luzin set. We show how to construct large family of pairwise non-equivalent
(I,J) - Luzin sets. We find a class of forcings which preserves the property of
being (I,J) - Luzin set.
We show that under some conditions on a family $\mathcal{A}\subset\bbi$ there
exists a subfamily $\mathcal{A}_0\subset\mathcal{A}$ such that $\bigcup
\mathcal{A}_0$ is nonmeasurable with respect to a fixed ideal $\bbi$ with Borel
base of a fixed uncountable Polish space. Our result applies to the classical
ideal of null subsets of the real line and to the ideal of first category
subsets of the real line.