In demographic research large scale individual data have become increasingly available. The quality of these datasets has seldom been assessed beyond comparisons with external sources such as lifetables, as opportunities for such assessments are rare. In this paper, we explore the quality of two Dutch demographic datasets by comparing life course reconstructions and family reconstitutions for individuals found in two different types of datasets. First, we use the HSN (Historical Sample of the Netherlands) which consists of a sample from the nationwide population register and follows life courses of a group of research persons in a historical context. Second, we use LINKS (Linking System for family reconstitution), based on vital event registration certificates. As the HSN is based on a sample of birth certificates and LINKS contains all vital events occurring in the province of Zeeland, individuals found in the HSN who are born in the province of Zeeland can be found in LINKS.

We use 495 persons who are found in both the HSN and in LINKS from the birth cohort 1863 to 1873. This paper constitutes a first attempt to compare life course reconstructions and family reconstitutions in demographic datasets based on different sources and constructed using different methods. Our purpose is threefold: to assess the quality of the datasets; to assess the usefulness of the data for different research questions including research on life spans and mortality, marriage behavior and fertility, and to determine how cases which are as complete as possible can be selected for analysis in a careful manner.