This paper is about the methodology of the time buget research. To conduct the time buget research, we have to classify the activities to various categories in time budget survey. There are two works to classify activities: making the coding system and applying such coding system to each activity.
This paper explains the coding systems of major time budget surveys and points out the various problems in terms of the activity classification.
The multinational comparative time budget project, directed by A. Szalai, provided us many guidelines to conduct the time budget research. The project used a two-digit coding system in which activities listed in the respondents' diaries were coded into one of 96 activity categories. Time budget surveys in Japan conducted by NHK and Statistics Bureau, Management and Coordination Agency Japan use another coding system.
There are various problems in terms of the activity classification. How do we decide the more reduced category of the smallest activity code? Is 'meals at work' work or meals? We have to develop the standard category of activities for the comparison of various time budget surveys. Activity codes for preschool children must be different from those for adult people. It is important that we understand the limitation of the coding system to develop the better analyses of time budget data.