Definedness

Questions of definedness are ubiquitous in mathematics. Informally, these involve reasoning about expressions which may or may not have a value. This paper surveys work on logics in which such reasoning can be carried out directly, especially in computational contexts. It begins with a general logic of partial terms, continues with partial combinatory and lambda calculi, and concludes with an expressively rich theory of partial functions and polymorphic types, where termination of functional programs can be established in a natural way.Lecture for mini-conference on Partial Functions and Programming: Foundational Questions, U.C. Irvine, 17 February 1995. I wish to thank Professor Karel Lambert for his work in organizing this conference. (Research supported by grants from the N.S.F.)     

The mediating role of anxiety in self-reported somatic complaints of depressed adolescents

This study examined the mediating role of anxiety in the self-reports of somatic complaints in 96 depressed adolescent inpatients. Sixty-four subjects with major depressive episodes and comorbid anxiety disorders (MDE-A) determined from the Diagnostic Interview for Children and Adolescents-Revised (DICA-R) reported significantly more somatic complaints than 32 adolescents having major depressive episodes without comorbid anxiety (MDE). An analysis of covariance demonstrated that, with anxiety symptoms controlled, MDE and MDE-A groups did not differ significantly in somatic complaints. A hierarchical multiple-regression analysis revealed that, with demographic and anxiety symptoms controlled, depressive symptoms did not contribute to the explanation or prediction of somatic complaints. The results suggest that anxious, but not depressive symptoms, are independently associated with somatic complaints. The results are discussed in light of new affective models of psychopathology.     

Challenges confronting cross-sex friendships: “Much ado about nothing?”

This research was an investigation into four challenges purported to confront cross-sex friends. One hundred and thirty eight individuals (females = 86, males = 52) completed two surveys designed to explore the extent to which the sexual, emotional bond, audience, and equality challenges were present in their cross-sex friendships. Over 98% of the participants were heterosexual, 99% were Caucasian, and approximately 5% were Hispanic. Data gathered from the first survey were analyzed using a three-way analysis of variance, with gender, type of friendship, and romantic status as the independent variables, and three of the four challenges as the dependent variables. The first survey also included open-ended questions designed to explore the nature and existence of the challenges. The second survey was in a diary format. Respondents kept a frequency count for three weeks of discussions they had with their cross-sex friend concerning the challenges, and thoughts that they had as individuals concerning those challenges. Results from both surveys indicate that though the challenges exist and have powerful effects on a small percentage of individuals in cross-sex friendships, for the majority of participants the challenges are not perceived as salient.     

Sentence Context and Word Recognition in Children with Average Reading Ability and with a Specific Reading Disability

The inhibitory and facilitatory effects of context on word recognition were investigated in 24 8-to 10-year-old children with a specific reading disability in comparison with a group of 24 children matched for reading ability and a group of 24 children matched for chronological age. To avoid confounding the effects of reading level with those of word difficulty, target words of equivalent relative familiarity for each participant were presented in congruous, neutral, and incongruous sentence contexts. In agreement with previous studies, there was clear evidence of both general inhibitory and facilitatory effects. In contrast to previous findings, however, reading level did not have a major impact on the inhibition of word recognition in incongruous contexts compared with neutral contexts, although it may have led to greater facilitation in congruous contexts compared with neutral contexts. Although further research is required, these results suggest that if reading-age appropriate materials are selected, less skilled readers and those with a reading disability may not be as influenced by context as has been claimed previously.     

Change in goals and values of men and women from early to mature adulthood

Changes in goals and values between early and middle adulthood were investigated using a longitudinal sample of women and their male partners. Measures designed to assess personality changes as described by Gutmann and Jung were coded from open-ended responses to questions about middle-aged subjects' concurrent and recollected goals and values. The findings indicated that both women and men declined in gender-traditional goals and values and increased in individual goals and values. Archival data for women showed that recollections were accurate and that both cohort and personality factors were related to the extent to which individuals' goals and values changed over time.     

Sex differences in reinforcement and punishment on prime-time television

Prime-time television programs were analyzed for frequencies of positive reinforcement and punishment exchanged among performers varying in age and sex. Results indicated that most responses were given by and directed to adult males. Moreover, while adult males exhibited and received similar frequencies of reinforcement and punishment, adult females were likely to give and to be the recipients of more reinforcement than punishment. Proportional analyses which controlled for sex differences in frequencies of responses revealed that females more often exhibited and received reinforcement, whereas males more often exhibited and received punishment. Results are interpreted from a social learning theory perspective and the implications for children's learning of positive and negative behaviors are explored.     

Exercise, changes in aerobic capacity, and changes in self-perceptions: An experimental investigation

Subjects in an exercise training condition participated in a 10-week aerobic exercise class, whereas subjects in waiting-list control and independent control conditions did not. The results indicated that subjects in the training condition evidenced reliably greater improvements in physical fitness (aerobic capacity) and reported reliably greater improvements in their abilities and confidence in both the physical area (e.g., ability to run distances) and nonphysical area (e.g., frustration tolerance) than did subjects in the control conditions. On the other hand, improvements in physical fitness were not related to reported improvements in abilities and confidence. These findings are of interest because they indicate that some of the important personal changes that are associated with physical fitness training are not due to changes in fitness, but appear to be due to other factors (e.g., group participation and expectancies).