Intra- and interobserver errors in facial flatness measurements

Citation
T. Hanihara et al., Intra- and interobserver errors in facial flatness measurements, ANTHROP SCI, 107(1), 1999, pp. 25-39
Citations number
18
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Sociology & Antropology
Journal title
ANTHROPOLOGICAL SCIENCE
ISSN journal
0918-7960 → ACNP
Volume
107
Issue
1
Year of publication
1999
Pages
25 - 39
Database
ISI
SICI code
0918-7960(199901)107:1<25:IAIEIF>2.0.ZU;2-I
Abstract
This study examines intra- and interobserver errors in the facial flatness measurements defined by Yamaguchi (1973) using two-way ANOVA with replicati on. The sample used consists of 10 recent Japanese skulls from Tohoku Distr ict. These skulls are measured twice by each of 6 observers. The interactio ns between skulls and observers are significant in the frontal chord, the s imotic subtense, and the zygomaxillary chord. In the latter 2 items, intero bserver errors are not significant, suggesting the nature of differences va ries from skull to skull. When the among-skull mean squares over the mean s quares of total error are tested, they are significant at <0.1% level in al l the items. The variance components expressed as percentages of the sum of variances indicate that intraobserver and total error variances are, on av erage, the largest in the simotic region, the second largest in the frontal region, and the smallest in the zygomaxillary region. On average, however, the variance components of among-skulls are very large in all the items. T hese indicate that it may be safe to use the facial flatness measurements o btained by different investigators in analyses of population affinities whe n the morphological differences among the populations are relatively large. The students employing facial flatness measurements in the study of popula tion affinities should, however, pay attention to the measurement errors, e specially those of simotic measurements, in interpretation of the biologica l significance of their results. The results of two-way ANOVA and nested AN OVA are also discussed in terms of the interaction components.