internal workings make it unsuitable for a single comprehensive explanatory model. Indeed,
SI performance implies such a co-occurrence of skills and processes (cognitive, linguistic,
emotional and behavioural) that many authors are rightly suggesting that investigations in
the field be directed to the analysis of individual components (skill components, Moser and
Lambert, 1994; with particular reference to memory, Darò, 1994; delivery quality, Viezzi …