Belfast Telegraph Poll 2013: Question of religion remains sensitive
On the question of religion, 20.2% of people answered 'other' and 21.9% answered 'none'.
Although the poll was carried out across a representative range of areas, it differed from the census, where around 6% of people fell outside the Catholic and Protestant categories.
A partial explanation lies in the different ways the census and fair employment figures label people Catholic or Protestant.
In the case of the census, people are asked the religion of the family they were brought up in.
In the fair employment figures, local people who classify themselves as not belonging to either of the main Christian denominational groups are often allocated according to the school they attended or some other factor.
LucidTalk pollsters accept a person's first answer on their religious or political beliefs and do not press for background details.
A 2007 survey by the Christian charity Tearfund found 45% of Northern Ireland people attended church regularly – the highest proportion in the UK but well down on previous estimates.
Some respondents may also be reluctant to give their religion to a stranger, however many people gave political and voting intentions which may be considered potentially more sensitive.