Roger Bakeman

Recommended effect size statistics for repeated measures designs.

Investigators, who are increasingly implored to present and discuss effect size statistics, might comply more often if they understood more clearly what is required. When investigators wish to report effect sizes derived from analyses of variance that include repeated measures, past advice has been problematic. Only recently has a generally useful effect size statistic been proposed for such designs: generalized eta squared (ηG2; Olejnik & Algina, 2003). Here, we present this method, explain that ηG2 is preferred to eta squared and partial eta squared because it provides comparability across between-subjects and within-subjects designs, show that it can easily be computed from information provided by standard statistical packages, and recommend that investigators provide it routinely in their research reports when appropriate.

Explaining disparities in HIV infection among black and white men who have sex with men : a meta-analysis of HIV risk behaviors

Objective:To identify factors that contribute to the racial disparity in HIV prevalence between black and white men who have sex with men (MSM) in the United States. Methods:A comprehensive literature search of electronic databases, online bibliographies, and publication reference lists yielded 53 quantitative studies of MSM published between 1980 and 2006 that stratified HIV risk behaviors by race. Meta-analyses were performed to compare HIV risks between black and white MSM across studies. Results:Compared with white MSM, black MSM reported less overall substance use [odds ratio (OR), 0.71; 95% confidence interval (CI), 0.53–0.97], fewer sex partners (OR, 0.64; 95% CI, 0.45–0.92), less gay identity (OR, 0.29; 95% CI, 0.17–0.48), and less disclosure of same sex behavior (OR, 0.42; 95% CI, 0.30–0.60). HIV-positive black MSM were less likely than HIV-positive white MSM to report taking antiretroviral medications (OR, 0.43; 95% CI, 0.30–0.61). Sexually transmitted diseases were significantly greater among black MSM than white MSM (OR, 1.64; 95% CI, 1.07–2.53). There were no statistically significant differences by race in reported unprotected anal intercourse, commercial sex work, sex with a known HIV-positive partner, or HIV testing history. Conclusions:Behavioral risk factors for HIV infection do not explain elevated HIV rates among black MSM. Continued emphasis on risk behaviors will have only limited impact on the disproportionate rates of HIV infection among black MSM. Future research should focus on the contribution of other factors, such as social networks, to explain racial disparities in HIV infection rates.

Joint Engagement and the Emergence of Language in Children with Autism and Down Syndrome

Systematic longitudinal observations were made as typically developing toddlers and young children with autism and with Down syndrome interacted with their caregivers in order to document how joint engagement developed over a year-long period and how variations in joint engagement experiences predicted language outcome. Children with autism displayed a persistent deficit in coordinated joint attention; children with Down syndrome were significantly less able to infuse symbols into joint engagement. For all groups, variations in amount of symbol-infused supported joint engagement, a state in which the child attended to a shared object and to language but not actively to the partner, contributed to differences in expressive and receptive language outcome, over and above initial language capacity.

Breif Report: Sensory Abnormalities as Distinguishing Symptoms of Autism Spectrum Disorders in Young Children

The purpose of this study was to explore the sensory profile of young children with ASD compared to young children with other developmental delays (DD) at first ASD assessment. Results found that young children with ASD had more tactile and taste/smell sensitivities and difficulties with auditory filtering than young children with other DD. Moreover, sensory scores were significantly correlated with stereotyped interests and behaviors. These findings support the hypotheses that young children with ASD show more sensory impairments than young children with other DD and that sensory symptoms are significantly related to stereotyped interests and behaviors. Results also suggest that sensory abnormalities are distinguishing symptoms of ASD that should be considered in diagnostic algorithms for younger cohorts.

Concordance of Self- and Informant Ratings of Adults' Current and Childhood Attention-Deficit/Hyperactivity Disorder Symptoms

Self-informant rating concordance for attention-deficit/hyperactivity disorder (ADHD) symptoms was assessed in 281 adults at the subscale (Inattention, Hyperactivity-Impulsivity) and individual symptom levels. Potential demographic, diagnostic, and informant identity moderators were also investigated. Concordance levels were similar for current and childhood symptoms. Although moderate positive correlations were found between self- and informant ratings on both subscales, informants endorsed more significant inattentive symptom severity. Kappa coefficients were variable, suggesting low concordance for certain symptoms. Sex and ADHD diagnosis moderated concordance, although effect sizes were small. These results have implications for the use of behavior rating scales in diagnosing ADHD, raise questions about the validity of self- and informant ratings, and support the need to investigate individual-differences variables that may impact concordance.

CRYING IN !KUNG SAN INFANTS: A TEST OF THE CULTURAL SPECIFICITY HYPOTHESIS

The pattern of crying and fretting behavior during the first two years is described for 46 !Kung San infants from a hunter‐gatherer society in northwestern Botswana. Despite markedly different caretaking practices predisposing to quieter infants, crying and fretting were significantly greater during the first three months, and a peak pattern was present. Measurement of crying ‘intensity’ indicated that it was predominantly short and fretful. The results support the concept that the early peak pattern is not specific to infants in western industrialized societies, and may represent a behavior universal to the human species. The caretaking differences between societies primarily appear to affect crying duration rather than its frequency and pattern in early infancy.

The Contribution of Early Communication Quality to Low-Income Children’s Language Success

The disparity in the amount and quality of language that low-income children hear relative to their more-affluent peers is often referred to as the 30-million-word gap. Here, we expand the literature about this disparity by reporting the relative contributions of the quality of early parent-child communication and the quantity of language input in 60 low-income families. Including both successful and struggling language learners from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, we noted wide variation in the quality of nonverbal and verbal interactions (symbol-infused joint engagement, routines and rituals, fluent and connected communication) at 24 months, which accounted for 27% of the variance in expressive language 1 year later. These indicators of quality were considerably more potent predictors of later language ability than was the quantity of mothers’ words during the interaction or sensitive parenting. Bridging the word gap requires attention to how caregivers and children establish a communication foundation within low-income families.

The Strategic Use of Parallel Play: A Sequential Analysis.

BAKEMAN, ROGER, and BROWNLEE, JOHN R. The Strategic Use of Parallel Play: A Sequential Analysis. CHILD DEVELOPMENT, 1980, 51, 873-878. Parallel play is often viewed as characteristic of a developmental stage through which children pass as they develop from solitary to social players. Here we examine parallel play, not as the hallmark of a given age but as it occurs sequentially in the stream of childrens play behavior. 41 children, ranging from 32 to 42 months, were observed during indoor free play, videotapes were encoded using a Partenlike scheme (Unoccupied, Solitary, Together, Parallel, and Group), and the data were examined using sequential analysis. Transitions into Group play (Partens Associative and Cooperative) from Parallel play were observed at greater than chance levels, and each of the children was observed to make this transition at least twice. We conclude that the movement from Parallel play to Group play may be more a matter of minutes than months, and that for the 32-42month-old children observed here Parallel play often functions in the stream of activities as a bridge to Group play.

Developmental milestones and disclosure of sexual orientation among gay, lesbian, and bisexual youths

Abstract A total of 63 males and 54 females from the southeastern United States who averaged 20 years of age (range=14–27) answered a questionnaire concerned with coming-out milestones, disclosure, and self-esteem for gay, lesbian, and bisexual youths. The mean ages for first awareness of same-sex attraction (11 years), first same-sex sexual contact (16 years), and first disclosure of their sexual identity (17 years) were similar to other recent young samples. The order of these milestones varied among subgroups of gays, lesbians, and bisexuals, and proportions who were out to one or both parents differed for bisexuals and African Americans. The findings suggest diverse individual trajectories as opposed to an invariant sequence of coming-out experiences and highlight the need for greater attention to individual differences in sexual orientation identity development.

Stress, coping, HIV status, psychosocial resources, and depressive mood in African American gay, bisexual, and heterosexual men

The associations between stress, physical health, psychosocial resources, coping, and depressive mood were examined in a community sample of African American gay, bisexual, and heterosexual men (N=139). Data were collected from physical exams and in-person interviews. In our theoretical framework, depressive mood scores were regressed first on stressors, next on psychosocial resources, and finally on coping strategy variables. Results revealed that psychosocial resources mediate the effects of stressors, including health symptoms, hassles, and life events, on depressive mood. There were no significant differences in depressive mood associated with HIV status or sexual orientation. Results are discussed in terms of community interventions needed to provide social support as a buffer between stress and psychological distress in African American men.