Collecting text messages from college students: Evaluating a novel methodology

Social interaction, particularly in older adolescents, increasingly involves computer‐mediated communication. Although studies of public computer‐mediated communication are increasingly common, studies of private text messaging remain rare. As approaches for obtaining such data evolve with technological advances, developmental scientists need designs in which to use such approaches that reduce sampling biases in both participants and text messages. In this study (n = 854; 46% male; 22% African American, 60% European American), we examined selection biases in the participant sample (i.e., factors associated with actual participation), procedural biases in the participant sample (i.e., factors related to failed data capture due to technological or procedural issues), and selection biases in the sample of text messages (i.e., based on self‐reported reasons for texting). Findings from our study suggest that studying human interaction directly through analysis of text message data is not only feasible, but also may be successfully undertaken with minimal biases regarding sample selection and text message selection among those who are engaged in research and engaged in text messaging outside of the study context. However, biases may occur depending on the type of platform (iPhone vs. Android) used by participants for texting.     

The Third Shift? Gender and Empowerment in a Women’s Ecotourism Cooperative

Ecotourism is lauded as a path toward sustainable development and women’s empowerment in rural areas around the world, but little is known about how gendered expectations shape its processes and outcomes. This paper employs an in-depth qualitative case study of a female-only ecotourism cooperative in rural Mexico to investigate how local gender dynamics influence women’s opportunities to benefit from ecotourism development. Findings show that women’s family and work commitments prevent their ability to devote the resources and energy necessary to make the cooperative successful. In this context, women are first expected to be wives and mothers, and to fulfill the substantial daily expectations associated with those roles. In addition, most women work outside the home. This leaves little time or energy for a “third shift” as ecotourism entrepreneurs running their own cooperative. Women put their own interests and goals on the back burner, because of the demands of the first two shifts. If ecotourism is to empower women, localized gender structures must be understood and addressed. Overlooking these challenges can mean that ecotourism projects, even those specifically aimed at empowering women, may only further burden women and reinforce gender models that perpetuate inequality.     

The economic fallout from divorce: Issues for the 1990s

Economic consequences of divorce, especially for women, are negative and persistent according to a range of research studies. The question is whether, given changing social circumstances, this negative economic fallout from divorce is likely to diminish in the 1990s and beyond. Dramatic changes suggest both reasons for optimism and pessimism. On the positive side are the trends toward more continuous labor force participation among women and smaller contemporary family sizes. Negative influences include changes in the labor market for women, continuing problems with child support compliance, the persistence of the wage gap, and the difficulties of combining parenting and employment.The writing of this paper was supported in part by National Institute on Aging grants AG04895 and AG06591. We are grateful to Marina Adler, Sharon Price, Mara Skruch and Lynn White for their helpful comments on an earlier draft of this paper.(Ph.D., University of Southern California) conducts research on divorce, widowhood, older women's issues, and family support in later life families.(Ph.D., University of North Carolina, Chapel Hill) focuses her research on divorce, bereavement, and the impact of life events on adjustment.(Ph.D., Case Western Reserve University) studies economic trends in U.S. society.     

Modelling age variation in survival and reporting rates for recovery models

In this paper, we focus on models for recovery data from birds ringed as young. In some cases, it is important to be able to include in these models a degree of age variation in the reporting probability. For certain models this has been found, empirically, to result in completely flat likelihood surfaces, due to parameter redundancy. These models cannot then be fitted to the data, to produce unique parameter estimates. However, empirical evidence also exists that other models with such age variation can be fitted to data by maximum likelihood. Using the approach of Catchpole and Morgan (1996b), we can now identify which models in this area are parameter-redundant, and which are not. Models which are not parameter-redundant may still perform poorly in practice, and this is investigated through examples, involving both real and simulated data. The Akaike Information Criterion is found to select inappropriate models in a number of instances. The paper ends with guidelines for fitting models to data from birds ringed as young, when age dependence is expected in the reporting probability.     

A Comparison of the Cost-efficiencies of the Sequential, Group-sequential, and Variable-sample-size-sequential Probability Ratio Tests

Wald and Wolfowitz (1948) have shown that the Sequential Probability Ratio Test (SPRT) for deciding between two simple hypotheses is, under very restrictive conditions, optimal in three attractive senses. First, it can be a Bayes-optimal rule. Second, of all level α tests having the same power, the test with the smallest joint-expected number of observations is the SPRT, where this expectation is taken jointly with respect to both data and prior over the two hypotheses. Third, the level α test needing the fewest conditional-expected number of observat ions is the SPRT, where this expectation is now taken with respect to the data conditional on either hypothesis being true. Principal among the strong restrictions is that sampling can proceed only in a one-at-a-time manner. In this paper, we relax some of the conditions and show that there are sequential procedures that strictly dominate the SPRT in all three senses. We conclude that the third type of optimality occurs rarely and that decision-makers are better served by looking for sequential procedures that possess the first two types of optimality. By relaxing the one-at-a-time sampling restriction, we obtain optimal (in the first two senses) variable-s ample-size- sequential probability ratio tests.     

Racial differences in marriage and childbearing: oral history evidence from the South in the early twentieth century

Using oral histories collected in 1938 and 1939 in the Southern United States, this article examines how African-Americans and whites viewed marriage and nonmarital childbearing. The authors document distinct racial differences in family norms and the sanctions that supported those norms. Giving birth outside a marital relationship was clearly not the stigmatizing event for African-Americans that it was for whites. The authors also found that African-Americans were more likely than whites to end marriages under similar conditions. These results suggest that debates about contemporary racial differences need to take into account the historical background, both cultural and demographic, of diverse groups.     

Explaining Family Change and Variation: Challenges for Family Demographers

Twenty years ago, the National Institute of Child Health and Human Development (NICHD) issued a request for proposals that resulted in the National Survey of Families and Households (NSFH), a unique survey valuable to a wide range of family scholars. This paper describes the efforts of an interdisciplinary group of family demographers to build on the progress enabled by the NSFH and many other theoretical and methodological innovations. Our work, also supported by NICHD, will develop plans for research and data collection to address the central question of what causes family change and variation. We outline the group's initial assessments of orienting frameworks, key aspects of family life to study, and theoretical and methodological challenges for research on family change. Finally, we invite family scholars to follow our progress and to help develop this shared public good.     

E-optimal design in irregular BIBD settings

When the necessary conditions for a BIBD are satisfied, but no BIBD exists, there is no simple answer for the optimal design problem. This paper identifies the E-optimal information matrices for any such irregular BIBD setting when the number of treatments is no larger than 100. A- and D-optimal designs are typically not E-optimal. An E-optimal design for 15 treatments in 21 blocks of size 5 is found.     

Empirical transform estimation for indexed stochastic models

We present a method for estimating the parameters in indexed stochastic models via a least squares approach based on empirical transforms. Asymptotic approximations are derived for the distribution of the resulting estimators. An explicit expression for the mean-squared error provides a natural way of selecting the transform variable, and a numerical example illustrates the performance of the resulting method. A common finding, which we term 'diagonal optimization', occurs when multiparameter models are fitted by using transforms. Diagonal optimization arises when optimal performance results from equating the elements of the transform vector, and we provide a heuristic explanation of why this occurs.