Longitudinal Research, Cross-sectional research
Longitudinal studies measure relationships between variables over a period of time. Involving information about an individual or group at different times throughout a long period.
For example, one might follow a group of males from birth to age 30 to measure their involvement with the criminal justice system over time and relate this information to their parents' socio-economic status.
A series of cross-sectional investigations taken over time will provide a longitudinal study. Recent developments in analytical methods and in data collection activities, including the growing number of longitudinal data sets in Canada and worldwide, have allowed for the increased reliance on powerful longitudinal approaches by research projects.
The Centre for Longitudinal Studies - Following lives from birth and through the adult years. - (CLS) is an ESRC Resource Centre based at the Institution of Education. - cls.ioe.ac.uk
Longitudinal studies of effects of divorce on children in Great Britain and the United States - AJ Cherlin, FF Furstenberg Jr, L Chase-Lansdale, KE Kiernan, PK Robins, DR Morrison, and JO Teitler - Department of Sociology, Johns Hopkins University.
National, longitudinal surveys from Great Britain and the United States were used to investigate the effects of divorce on children. In both studies, a subsample of children who were in two-parent families during the initial interview (at age 7 in the British data and at ages 7 to 11 in the U.S. data) were followed through the next interview (at age 11 and ages 11 to 16, respectively).
At both time points in the British data, parents and teachers independently rated the children's behavior problems, and the children were given reading and mathematics achievement tests. At both time points in the U.S. data, parents rated the children's behavior problems. Children whose parents divorced or separated between the two time points were compared to children whose families remained intact. For boys, the apparent effect of separation or divorce on behavior problems and achievement at the later time point was sharply reduced by considering behavior problems, achievement levels, and family difficulties that were present at the earlier time point, before any of the families had broken up. For girls, the reduction in the apparent effect of divorce occurred to a lesser but still noticeable extent once preexisting conditions were considered.
Legacies and Lessons: Insights
from Longitudinal Studies of Educated Women.
Abstract: Postmodern, multicultural, and feminist critiques of psychology have changed how longitudinal researchers construct their inquiries and frame their data. Also the new scholarship brings to the longitudinal investigation perspectives from other disciplines including sociology, anthropology, and history, among others. The book used as a framework for this discussion, "Women's Lives Through Time," is an assembly of different studies, thus providing perspective on the changing discipline of longitudinal research. Many studies on women were out of print and there was an absence of interdisciplinary dialogue about women's adult development. Some broad themes weaving together all the studies are: (1) all of the women studied had attended college; (2) strong evidence existed for increased well-being and feelings of competence in women as they mature; and (3) all the women were affected by role socialization and gender discrimination. The studies included in the book indicated that longitudinal methodologies have diversified over the years. More subjective and context-sensitive methods were incorporated; some caution needs to be taken to ensure that the research retains analysis of measurable data. Another methodological challenge has to do with incorporating issues of socio-historical context into lifespan research. Incorporating subjective and contextual material is the wave of the future in life studies research.
Longitudinal Studies of Attitude Change: Issues and Methods.
Abstract: This report makes available in condensed form the methods for performing longitudinal studies of attitude change and the issues associated with these methods. It represents a state-of-the-art review of such methods, and the material covered spans the disciplines of psychology, sociology, and statistics. It is meant to provide a brief description of the tools available, references to more detailed descriptions, and an overview of the theoretical and practical issues involved in execution and interpretation to those wishing to employ longitudinal methodology. The report is divided into the following four sections: (a) Longitudinal design and cross-sectional design are compared in terms of relative advantages and disadvantages. (b) Theoretical issues associated with studies done over time, such as the overcorrection/the overall variance, are discussed. (c) Actual methods are described; this section is subdivided into (a) experimental designs, (b) quasi-experimental designs, and (c) statistical techniques. This section also includes references to actual studies in which these methods were employed. (d) Practical considerations in doing longitudinal research are discussed. The major conclusion drawn in the report is that while sophisticated methods are available for use, overall development of the field is being hampered because work progresses independently in several disciplines.
Weatherall, R, H Joshi, S Macran. Double burden or double blessing - employment, motherhood and mortality in the Longitudinal-Study of England and Wales. Social Science & Medicine 1994; 38 (2): 285-297.
The OPCS Longitudinal Study has been used to follow up women who were married at the time of the 1971 census, to see if their employment status and responsibility for children at that time had any detectable consequence for their mortality up to 1985. Of particular interest was whether the combination of employment and child rearing produced any signs of role overload, or its opposite hypothesized effect, role enhancement. The results show poorer health among those with neither employment nor children, but these effects did not appear to interact. We suspect the data reveal health selection as much as health effects of the roles taken separately.
How to handle informed consent in longitudinal studies when participants have a limited understanding of the study
G Helgesson, The Centre for Bioethics at Karolinska Institutet and Uppsala University, Sweden
J Ludvigsson, U Gustafsson Stolt, The Division of Paediatrics at the Department of Molecular and Clinical Medicine, Link�ping University, Sweden
Empirical findings from a Swedish longitudinal screening study show that many of the research subjects had a limited understanding of the study. Nevertheless they were satisfied with the understanding they had and found it sufficient for informed continued participation. Were they wrong? In this paper, it is argued that the kind of understanding that is morally required depends partly on the kind of understanding on which the research subjects want to base their decisions, and partly on what kind of knowledge they lack. Researchers must ensure that the information process is not flawed and that participants receive the information they want. To achieve this, new information efforts may be needed. Researchers must also ensure that research subjects have knowledge about aspects of importance to them. Lack of understanding may, however, be the result of conscious choices by research subjects to disregard some of the information because it is not important to them. Such choices should normally be respected.
Moser, K A, P O Goldblatt. Mortality of Women in the OPCS Longitudinal Study: Differentials by Own Occupation and Household and Housing Characteristics. LS working paper 26. 1985.
Moser, K A, P Goldblatt. Mortality of Women in Private and Non-private Households Using Data from the OPCS Longitudinal Study. LS working paper 14. 1984.
Macran, S. Analysis of women's mortality using the OPCS Longitudinal Study. In: OPCS / SSRU Longitudinal Study Newsletter No. 9 (November 1993). 1993. p. 4-7.
Lyons, M. Chaos or complexity? Casualisation, feminisation and gentrification in London, 1971-1991. In: Creeser, R, Gleave, S, editors. Migration Within England and Wales Using the Longitudinal Study. ONS Series LS, No. 9. London: The Stationery Office; 2000. p. 49-61.
Harrop, A, H Joshi. Death and the Saleswoman: an Investigation of Mortality and Occupational Immobility of Women in the Longitudinal Study of England and Wales. LS working paper 73. 1994.
Goldblatt, P O. Social Class Mortality Differentials of Men Aged 15-64 in 1981: a Note on First Results from the OPCS Longitudinal Study for the period 1981-83. LS working paper 42. Updated version in Population Trends No 51. 1986.
Fox, A J, D R Jones. 1971-81 Male Socio-Demographic Mortality Differentials from the OPCS Longitudinal Study. LS working paper 21. Shortened version published in Population Trends, 1985, 40: 10-16. Full version published in P O Goldblatt, Proceedings of the American Statistical Association Meeting, August 13-16, 1984. 1984.
Fielding, A J, S Halford. A longitudinal and regional analysis of gender-specific social and spatial mobilities in England and Wales, 1981-91. In: Boyle, P, Halfacre, K, editors. Migration and Gender. London: Routledge; 1998.
Fielding, A J. Gender, class and region in England and Wales - a longitudinal analysis. Ritsumeikan University Geographical Journal, Kyoto 1998; 10: 1-22.
Donkin, A. Does living alone damage men's health? Reports on an analysis of the relationship between living alone and risk of death or limiting long-term illness for men who were present in the Office for National Statistics Longitudinal Study (LS) in both 1971 and 1981. Health Statistics Quarterly 2001; 11 (Autumn 2001): 11-16.
Blackwell, L. Women and Science Teaching: the Demographic Squeeze. Report to the DTI. mimeo. Centre for Longitudinal Studies; 2001.