Background: The National Health Interview Survey (NHIS) was used to ascertain whether increases in inadequate sleep differentially affected black and white Americans. We tested the hypothesis that prevalence estimates of inadequate sleep were consistently greater among blacks, and that temporal changes have affected these two strata differentially.

Methods: NHIS is an ongoing cross-sectional study of non-institutionalized US adults (≥18 years) providing socio-demographic, health risk, and medical factors. Sleep duration was coded as very short sleep [VSS] (<5 h), short sleep [SS] (5–6 h), or long sleep [LS] (>8 h), referenced to 7–8 h sleepers. Analyses adjusted for NHIS’ complex sampling design using SAS-callable SUDAAN.

Results: Among whites, the prevalence of VSS increased by 53 % (1.5 % to 2.3 %) from 1977 to 2009 and the prevalence of SS increased by 32 % (19.3 % to 25.4 %); prevalence of LS decreased by 30 % (11.2 % to 7.8 %). Among blacks, the prevalence of VSS increased by 21 % (3.3 % to 4.0 %) and the prevalence of SS increased by 37 % (24.6 % to 33.7 %); prevalence of LS decreased by 42 % (16.1 % to 9.4 %). Adjusted multinomial regression analysis showed that odds of reporting inadequate sleep for whites were: VSS (OR = 1.40, 95 % CI = 1.13-1.74, p < 0.001), SS (OR = 1.34, 95 % CI = 1.25-1.44, p < 0.001), and LS (OR = 0.94, 95 % CI = 0.85-1.05, NS). For blacks, estimates were: VSS (OR = 0.83, 95 % CI = 0.60-1.40, NS), SS (OR = 1.21, 95 % CI = 1.05-1.50, p < 0.001), and LS (OR = 0.84, 95 % CI = 0.64-1.08, NS).

Conclusions: Blacks and whites are characteristically different regarding the prevalence of inadequate sleep over the years. Temporal changes in estimates of inadequate sleep seem dependent upon individuals’ race/ethnicity.

The Writing Pal (W-Pal) is an intelligent tutoring system (ITS) designed to provide students with explicit writing strategy instruction and practice. W-Pal includes a suite of educational games developed to increase writing engagement and provide opportunities to practice writing strategies. In this study, first (L1) (n = 26) and second (L2) language (n = 16) students interacted with W-Pal over eight sessions. We collected students’ daily self- reports of engagement, motivation, and perceptions of performance, as well as their reported game attitudes (difficulty, helpfulness for learning, and enjoyment). Results indicated that, for all students, interactions with W-Pal led to increases in writing performance and more positive attitudes towards the system (engagement, motivation, and perceived performance). For L1 students, game difficulty was a significant predictor of boredom; however, for the L2 students, game enjoyment predicted both their motivation and perceived writing improvement. Notably, the L2 students’ game ratings accounted for more variance in these daily reports than did the ratings of L1 students. This study suggests that L1 and L2 students experience similar benefits offered by game-based strategy practice in an ITS. Further, the link between game attitudes and overall daily perceptions of training may be stronger for L2 students than L1 students.