  The credibility of an eclipse timing variation (ETV) diagram analysis is
investigated for various manifestations of the mass transfer and gravitational
radiation processes in binary systems. The monotonicity of the period
variations and the morphology of the respective ETV diagrams are thoroughly
explored in both the direct impact and the accretion disk mode of mass
transfer, accompanied by different types of mass and angular momentum losses
(through a hot-spot emission from the gainer and via the L2/L3 points). Mass
transfer rates comparable to or greater than 10^{-8} M_sun/yr are measurable
for typical noise levels of the ETV diagrams, regardless of whether the process
is conservative. However, the presence of a transient disk around the more
massive component defines a critical mass ratio q_cr ~ 0.83 above which the
period turns out to decrease when still in the conservative regime, rendering
the measurability of the anticipated variations a much more complicated task.
The effects of gravitational radiation proved to be rather undetectable, except
for systems with physical characteristics that only refer to cataclysmic
variables. Unlike the hot-spot effects, the Lagrangian points L2 and L3 support
very efficient routes of strong angular momentum loss. It is further shown that
escape of mass via the L3 point - when the donor is the less massive component
- safely provides critical mass ratios above which the period is expected to
decrease, no matter how intense the process is.
