  The aim of this work is to summarize the main underlying assumptions,
simplifications and uncertainties while studying solar energetic particles
(SEPs). In general, numerous definitions are used for the evaluation of a given
SEP parameter and these different methods lead to different outcomes for a
given particle event. Several catalogs of SEP events from various instruments
are currently available; however, each catalog is specific to the adopted data
and analysis. We investigate the differences while comparing several SEP
catalogs and outline probable reasons. We focus on SEP statistical studies and
quantify the influences of the particle intensity magnitude, solar origin
location and projection effects. We found that different definitions and
criteria used for these parameters change the values of the correlation
coefficients between the SEPs and their solar origin.
