Sir, – I note that the article "It's nice if your glass is always half full, but are you deluding yourself?" (Joe Humphreys, Unthinkable, January 20th) includes the time-worn illustration of the half-full/half-empty glass. As a scholar of operations management, can I advise that the glass is merely operating at 50 per cent capacity. – Yours, etc,
Prof MICHAEL NELSON,
Stillorgan, Co Dublin.
Sir, – Should the glasses be described as both full as they are half water and half air? – Yours, etc,
READ SOME MORE
BRID FITZPATRICK,
Dublin 6W.