3.3. Non peer-reviewed literature
The main sources for this search were the Internet, some CDROMs
and books from relevant conferences and workshops, and
also edited books. Following a first, rough Internet search carried
out with the help of some PhD students in the third quarter of
2008, twelve conferences with at least five relevant papers or
extended abstracts were identified (Table 1). From these sources
1320 abstracts were screened to identify papers relevant to OBIA
and 349 abstracts were identified as being related to OBIA in a
broad sense.
Other conferences and other documents available as CD-ROMs
or over the Internet were pre-screened and another 242 not
fully peer-reviewed articles were identified as relevant to OBIA.
For these sources, error of omission missing the occasional
conference paper is not critical to obtaining a valid result, since
this is not an absolute measurement.