Linkage Results Concluding Remarks

8. Time Requirements of the Linking Process

The good results are not achieved without investment. The linking of the 100,000 events required about 2400 hours in front of the computer. In addition comes the time to computerize the sources. Some of this work I did myself; some was done by a graduate student, some was done by other agencies. The latter data had to be converted and adapted to the Demolink system. How much time was spent on these parts of the project is unknown.

The average amount of time spent on the interactive linking of one individual with more than one event in the life course was more than 8 minutes. The record linkage required high concentration, and the hours in front of the computer were quite tiring to eyes and brain, five hours a day was the average. Most life courses were linked very smoothly and quickly, very often in 2-3 minutes. Linking people with common names consumed much more time.

It is not easy to find comparable estimates on time spent on traditional family reconstruction; each project seems to have its own sources and its own consumption of time. An investigation for a population of 1000 - 1500 people for 100 years is in Norway considered to give more than a year, i.e. more than 1750 hours, of work. E. A. Wrigley estimates 1500 hours for English parishes of a size of 1000 people for three centuries. J. Dupâquier reckons 2 hours of work for each family of type MF (date of marriage and end of union known) in France [Dyrvik 1983,95, Wrigley 1966,97, Dupâquier 1984,11]. The reason why the Norwegian estimate is higher than the English may be that not only church records, but also census returns and other nominative sources are frequently used in Norwegian studies.

At first glance, then, the worktime saved by using the Demolink system seems marginal. The figures for time spent in manual family reconstitution, however, are, all based on much smaller data sets than the one from Asker and Bærum. The amount of time spent on linkage increases exponentially with the size of the parish. So, there is definitely time to be saved with Demolink. Even more important is that with such a large amount of data, it would be impossible to maintain an overview while using manual methods. Finally the data is ready for efficient analyses with the aid of a computer.


Linkage Results Concluding Remarks

Interactive Record Linkage: The Cumulative Construction of Life Courses
Eli Fure
© 2000 Max-Planck-Gesellschaft ISSN 1435-9871