EN
Selected results of two surveys conducted in 1977 and 1984 among the adult population of the city of Łódź were compared aiming at the demonstration of two kinds of problems: 1) those related with the construction of a replicated sample in 1984; 2) those related with historical incomparability of the meaning of certain questions asked in two different socio-political contexts. It was also ascertained that in 1984 respondents were generally much more reticent in their replies to open-ended questions - especially white coller workers and pensioners. A method of recalculation of percentages of certain replies in 1984 to make them more comparable with higher percentages obtained in 1977 is proposed.