The measurement selection
algorithm was applied to find a minimal set of observations required
to establish
a diagnosable system. In principle,
measurement selection is based on the temporal
structure of the graph, and, therefore, no numeric information is used.
However,
when 
or 
is low
numeric information can be applied to determine whether
the relation 
is 1 or -1
instead of generating unknown as is done
when or is high.