In his spare time, O'Neill, who has been profoundly deaf since birth, heads a project aimed at expanding the representation of mathematical and
statistical terminology in British Sign Language (BSL).
Traditionally, however, the bulk of mediation analysis has been conducted within the confines of linear regression,
with statistical terminology masking the causal character of the relationships involved.
In
statistical terminology, these assumptions comprise a statistical model because they define a statistical relationship among the data.