In four surveys dealing with older people and different aspects of their quality of life in the Czech Republic (carried out since 2007 until December 2011) were collected information on subjective health, subjective age, general satisfaction with the development of society, and the Philadelphia Geriatric Centre Morale Scale (PGCM). In all of these surveys we were also able to follow both interviewee sex and age. In the first part of our presentation we will show the results of the tests if and how interviewee and questionnaire characteristics influence the outcomes of these variables in older subjects. In the second part we will present some examples of varying results based on differences in question usage in the quantitative surveys of older adults. Two waves of the “QinCity – Quality of life of older people in the cities” survey will be used in this second part. This survey was carried out in June and December 2011 in the Czech Republic with residents of inner cities aged 60 and older (total N = 1901). While both waves were aimed at similar samples and covered the same topic, some of the questions and conditions were altered between the waves. The results shall enhance current methodological discussion in ageing research.