Molto J E
Am J Phys Anthropol. 1979 Sep;51(3):333-44. doi: 10.1002/ajpa.1330510304.
Intraobserver scoring precision of 50 discontinuous (discrete) cranial traits was assessed on a sample of 125 intact Iroquois crania using the square of the phi coefficient. Scoring consistency was high for most traits although several were subject to low precision (phi 2 less than 0.7). Most errors were random rather than systematic. Taken collectively the problematic traits exceeded their expected contribution to MMD coefficients among four Woodland samples from southern Ontario. A traitlist with the problematic variants excluded produced more meaningful biological relationships among the samples. Further, the % contribution of the problematic traits increased with the time interval between the scoring of the individual samples. It was suggested that intraobserver error could effectively distort the interpretation of biological relationships and that it must in part be responsible for the poor performance reported for discontinuous traits in some studies. Therefore, it was argued that the results support rather than compromise the use of discontinuous skeletal traits in population studies and that the assessment of intraobserver error should be a standard procedure of the research design.
使用phi系数的平方，对125个完整的易洛魁人头骨样本的50个不连续（离散）颅骨特征进行了观察者内评分精度评估。大多数特征的评分一致性很高，尽管有几个特征的精度较低（phi平方小于0.7）。大多数误差是随机的，而非系统性的。总体而言，在来自安大略省南部的四个林地样本中，有问题的特征对MMD系数的贡献超过了预期。排除有问题变体的特征列表在样本之间产生了更有意义的生物学关系。此外，有问题特征的百分比贡献随着各个样本评分之间的时间间隔而增加。有人认为，观察者内误差可能会有效地扭曲对生物学关系的解释，并且在一定程度上必然是某些研究中不连续特征表现不佳的原因。因此，有人认为这些结果支持而非损害在群体研究中使用不连续骨骼特征，并且观察者内误差的评估应该是研究设计的标准程序。
