  The determination of the primary cosmic ray mass composition from the
longitudinal development of atmospheric cascades is still a debated issue. In
this work we discuss several data analysis methods and show that if the entire
information contained in the longitudinal profile is exploited, reliable
results may be obtained. Among the proposed methods FCC ('Fit of the Cascade
Curve'), MTA ('Multiparametric Topological Analysis') and NNA ('Neural Net
Analysis') with conjugate gradient optimization algorithm give the best
accuracy.
