1168 translator reviewed the translations for accuracy. Open coding was used to develop substantive categories for parents’ responses to this question. Category development was based on the speciﬁc concepts that emerged from open coding and was guided by our general knowledge of the literature. The parents’ responses were coded for what we judged to be the most salient difﬁculty. The ﬁrst author independently coded all of the responses and developed a coding dictionary. The second author subsequently coded all of the responses, all differences were resolved (resulting in 100% agreement), and the coding dictionary was revised. Results Analytic Plan Quantitative analyses were performed using SPSS 15.0 for Windows. We used frequencies and cross-tabulations to summarize the number of topics discussed, parents’ per- ceived levels of comfort and knowledge in sexual com- munication, and the difﬁculties parents reported in sexual communication. Statistical signiﬁcance, at an alpha level of .05, was assessed by Chi-square test (for expected fre- quencies of fewer than ﬁve, we used Fisher’s exact test or, if computational limits were reached, the Monte Carlo approximation). We also employed hierarchical regression analyses to examine the relationships between parent and adolescent primary demographic variables, socio-demographic vari- ables, parent perceived comfort and knowledge regarding sexual communication, and parent reported sexual com- munication difﬁculties, with the dependent variable num- ber of topics discussed. Because of insufﬁcient sample sizes in the race categories other than White, only the Hispanic versus non-Hispanic ethnicity variable was included in the regression analyses, whereas the non-His- panic race categories reported in Table 1 were not used. Listwise deletion for missing values was employed for all variables (missing between 0 and 1.1%) except the open- ended item on sexual communication difﬁculties (missing of 7.2%), for which missing was included as one of two dummy variables (presence of difﬁculties and missing, vs. the reference category absence of difﬁculties) to allow for testing the effect of not answering this question. In addi- tion, adolescent gender and parent gender individually and in combination were included to allow for testing of the hypothesized parent–adolescent gender interaction. An alpha level of .05 was used to evaluate statistical signiﬁ- cance. Indices of multicollinearity (eigenvalues, condition indices, and variance proportions) were examined, and no problems were identiﬁed. 123 J Youth Adolescence (2010) 39:1164–1174 Descriptive Data Fifteen percent of parents did not discuss with their ado- lescent any of the six sex education topics we asked about, and 26% of parents discussed all six topics. The mean number of topics discussed was 3.5 out of 6 topics. The greatest proportion of parents (73.8%) said they discussed human reproduction; 70.6% discussed HIV/AIDS and other STIs, 64.5% avoiding sexual intercourse, 57.4% becoming sexually active, 52.2% using protection, and 33.4% where to get condoms. Table 2 presents the percentage of parents who dis- cussed each of the six topics with their adolescents, and mean numbers of topics discussed, by parent gender and by adolescent age level and gender. Signiﬁcant differences were found among both mothers and fathers in the per- centage who discussed the six topics with daughters versus sons at different age levels (p \ .05). The mean number of topics discussed by both mothers and fathers increased as adolescent age level increased. Mothers discussed a greater number of topics with preadolescent and early adolescent daughters than did fathers. The mean number of topics discussed with middle adolescent sons was greater for fathers than for mothers. Further, mothers discussed a greater number of topics with late adolescents than did fathers. Some gender-related communication patterns on spe- ciﬁc topics were observed. A greater proportion of fathers discussed avoiding sex with preadolescent and early adolescent daughters than with preadolescent and early adolescent sons. For late adolescence, a greater proportion of fathers discussed HIV/AIDS and other STIs with daughters than with sons, but a greater proportion dis- cussed using protection with sons than with daughters. Among mothers, a greater proportion discussed condoms with sons than with daughters in early, middle, and late adolescence. In addition, 100% of mothers discussed avoiding sex with late adolescent daughters, as compared with 79% who discussed the topic with late adolescent sons. In response to the questions about how comfortable they feel in talking with their adolescent about sex and rela- tionships, 52.4% of parents said they feel very comfortable, 25.8% said they feel somewhat comfortable, 15.3% said they feel somewhat uncomfortable, and 5.8% said they feel very uncomfortable (missing = 0.7%, N = 907). In response to the questions about how knowledgeable they feel in talking with their adolescent about sex and rela- tionships, 59.5% of parents said they feel very knowl- edgeable, 32.3% said they feel somewhat knowledgeable, 4.9% said they feel somewhat unknowledgeable, and 3.3% said they feel very unknowledgeable (missing = 0.8%, N = 907). In response to the open-ended question about