Introduction:
In social studies there occurs a risk of obtaining poorly reliable results due to the application of inadequate research instruments, or their incorrect design. Studies of the time budget of selected population groups constitute a special diffi culty because they most frequently use a survey method in which the duration of performance of individual activities is assessed, based on respondents’ retrospection.

Objective:
The objective of the study is the comparison of two methods of evaluation of the mean duration of work activities performed in the household and on the farm (questionnaire form, diaries of schoolchildren’s activities) by rural children aged 11-14.

Material and Methods:
The study covered a group of 255 children from rural families living in the Lublin region. The amount of time devoted by children in the study to work activities on the family farm was evaluated based on two sources of information: 1) questionnaire form, 2) and records in the diary of schoolchild’s activities.

Results:
Results of the analyses showed that the time budget of rural children specifi ed, based on the schoolchildren’s retrospection in survey studies, signifi cantly diff ered from that established based on the diaries they kept. According to the retrospective evaluation, time devoted to work activities performed on behalf of the family was considerably shorter than that specifi ed based on diaries. The underestimation of working time in the survey studies was characteristic in the group of girls, whereas among boys the evaluations based on the survey and diaries were similar.

Conclusions:
The applied methods of evaluation of working time on behalf of a family brought about slightly diff erent results. The diff erences in evaluations of individual work activities performed by a child should be analyzed in the context of the daily time budget. It is advisable to perform a comprehensive analysis of the conditioning of the diff erences observed