A study at the College of Physical Education discusses the likelihood of selecting volleyball referees according to refereeing performance, differentiation of legal knowledge, some mental abilities, and emotional traits.

A doctoral thesis at the College of Physical Education and Sports Sciences, University of Karbala, discussed the ability to classify distinguished and non-distinguished referees through the arbitration form prepared by the Central Iraqi Volleyball Federation, submitted by the doctoral student Sarmad Abd al-Rida al-Haider al-Husseini, in the presence of a number of university professors, in the discussion room.
The thesis aimed to build a test of legal knowledge, as well as build a measure of emotional traits, identify the discriminatory connotations, identify the classification of referees, as well as identify the odds ratios.
The thesis recommended the necessity of relying on the variables involved in discriminant analysis, as well as using this method on other sports.