The Stability of Rater Severity in Large-Scale Assessment Programs
摘要:
The purpose of this study was to investigate the stability of rater severity over an extended rating period. Multifaceted Rasch analysis was applied to ratings of 16 raters on writing performances of 8, 285 elementary school students. Each performance was rated by two trained raters over a period of seven rating days. Performances rated on the first day were re‐rated at the end of the rating period. Statistically significant differences between raters were found within each day and in all days combined. Daily estimates of the relative severity of individual raters were found to differ significantly from single, on‐average estimates for the whole rating period. For 10 raters, severity estimates on the last day were significantly different from estimates on the first day. These fndings cast doubt on the practice of using a single calibration of rater severity as the basis for adjustment of person measures.
allylsilanes to functionalized allenes was developed. Thermal decomposition of 1,1-dibromo-2-(silylmethyl)cyclopropanes, which were quantitatively prepared by treatment of allylsilane derivatives with CHBr3/KOtBu, afforded substituted 2-bromo-1,3-butadienes with elimination of bromosilanes. The Pd-catalyzed reaction of the bromodienes with soft nucleophiles gave the allene derivatives. Previously inaccessible
开发了将烯丙基硅烷转化为官能化烯的三步路线。1,1-二溴-2-(甲硅烷基甲基)环丙烷的热分解,通过用CHBr 3 / KO t处理烯丙基硅烷衍生物定量制备Bu,得到取代的2-溴-1,3-丁二烯,并且消除了溴硅烷。溴代双烯与软亲核试剂的钯催化反应生成了丙二烯衍生物。也可以通过该方法制备以前难以获得的三和四取代的烯。
A simple route to 1-bromobicyclo[1.1.0]butanes by intramolecular trapping of 1-bromo-1-lithiocyclopropanes
作者:Nils O. Nilsen、Lars Skattebøl、Mark S. Baird、Sheila R. Buxton、Paul D. Slowey
DOI:10.1016/s0040-4039(01)81317-4
日期:1984.1
NILSEN, N. O.;SKATTEBOL, L.;BAIRD, M. S.;BUXTON, SH!, R.;SLOWEY, P. D., TETRAHEDRON LETT., 1984, 25, N 27, 2887-2890
作者:NILSEN, N. O.、SKATTEBOL, L.、BAIRD, M. S.、BUXTON, SH!, R.、SLOWEY, P. D.
DOI:——
日期:——
SUBSTITUTED BENZOFURAN, BENZOPYRROLE, BENZOTHIOPHENE, AND STRUCTURALLY RELATED COMPLEMENT INHIBITORS