Sequence analysis: Its past, present, and future.

This article marks the occasion of Social Science Research's 50th anniversary by reflecting on the progress of sequence analysis (SA) since its introduction into the social sciences four decades ago, with focuses on the developments of SA thus far in the social sciences and on its potential future directions. The application of SA in the social sciences, especially in life course research, has mushroomed in the last decade and a half. Using a life course analogy, we examined the birth of SA in the social sciences and its childhood (the first wave), its adolescence and young adulthood (the second wave), and its future mature adulthood in the paper. The paper provides a summary of (1) the important SA research and the historical contexts in which SA was developed by Andrew Abbott, (2) a thorough review of the many methodological developments in visualization, complexity measures, dissimilarity measures, group analysis of dissimilarities, cluster analysis of dissimilarities, multidomain/multichannel SA, dyadic/polyadic SA, Markov chain SA, sequence life course analysis, sequence network analysis, SA in other social science research, and software for SA, and (3) reflections on some future directions of SA including how SA can benefit and inform theory-making in the social sciences, the methods currently being developed, and some remaining challenges facing SA for which we do not yet have any solutions. It is our hope that the reader will take up the challenges and help us improve and grow SA into maturity.

The start of the sexual transition in Mali: risks and opportunities.

Analysis of data from a questionnaire survey of 2,000 young Malians undertaken by the authors in 2002 demonstrates that, even in underprivileged urban and rural populations, changes in sexual behavior are emerging. Among women, first sex and motherhood are taking place slightly later, and a minority is now dissociating sexuality and procreation. Our data confirm the considerable impact of female education on this transition. Girls'sexual activity before procreation is also influenced by lower religiosity. Among men, in contrast, in a traditional context of late sexual debut and fatherhood, the trend is toward earlier sexual activity and procreation. Fatherhood is delayed, however, among better-educated, wealthier, and less religious urban men, who therefore experience a longer period of sexual activity before they begin to build their own families. The study concludes with an analysis of the possible association of the sexual transition with young people's increased vulnerability resulting from their adoption of risky sexual behaviors and from unfavorable conditions surrounding the arrival of their first child.