Page 109 - Anthropometry, Apparel Sizing and Design

72 Anthropometry, Apparel Sizing and Design

use a range of underwear/scan wear—this will depend on the objectives of the study, the
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requirements of commercial partners, cultural variations in a population, and the selected
scanner;
scan subjects who may not be able to remain still for longer than 8–10s;
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use survey-specific measurement sets that do not include dimensions that are listed in ISO
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standards (e.g., ISO 8559-1).
(See Allen et al., 2003, for an example of benchmarking.)
A key issue raised by the need for benchmarking is an assessment of the accuracy of
3-D scan capture, landmarking, and measurement extraction. ISO 20685 Parts 1 and 2
give guidance for reducing error in 3-D scanning and for establishing accuracy of body
dimensions by comparing traditional manual measurements with those extracted from
scanners. In addition, although such comparisons are still the subject of debate, it is
acknowledged that some scanners have now reached a stage of development where
they can automatically extract measurements from subjects with a higher accuracy
and consistency than those taken by trained anthropometrists. Notwithstanding these
advances and debates, what is perhaps as important is the need to agree definitions and
measurement positions. As can be seen in earlier work, where waist definitions of ISO
8559:1989 (now reissued as ISO 8559-1) are compared with those of a preferred waist
taken during the CAESAR study (Veitch, 2012) and where acceptable upper and lower
limits of the waist are compared to define the true height of the waist (Gill et al., 2014).

3.4.2.6 Statistics

The determination of a statistical sample of earlier clothing-specific surveys
(e.g., SizeUK) was based on the pioneering work of US military studies (Gordon
et al., 1989), and as can be seen in Table 3.3. I., the SizeUK study took place in three
geographical regions (the total population within each region was approximately
equal to obtain statistical relevant results), and each region was divided into seven
age bands.
However, an ISO standard (ISO 15535 General requirements for establishing
anthropometric databases) introduced in 2006 and revised in 2012 sets out options
for desired levels of relative accuracy and confidence—for stature, chest circumfer-
ence, and shoulder breadth—with proposed numbers of subjects for the achievement
of each level. How those numbers are distributed will depend on the number of regions
selected and their relative populations. Account needs to be taken of the homogeneity
of the population (e.g., age distribution, ethnicity, and socioeconomic status); a coun-
try, for example, that has a homogeneous population might be treated as a single
region. A further difference in the ISO standard is the age bands. For example, in
the case of the SizeUK survey, the lower adult age band was determined by the (then)
UK school leaving age of 16years, as those subjects could be included in a socioeco-
nomic category. It is suggested in ISO 15535:2012 that adult population data should
be collected from those aged over 20years of age and that young adults should be con-
sidered as single-year bands. No upper age limit is proposed, and as can be seen in
recent studies (Tables 3.1 and 3.2), there is a wide range of upper ages, but with an