The aims of this research are two-fold. First is to present and systematically analyze the bidirectional flint blade industries from PPNB sites throughout the southern Levant. This formal 'hallmark' PPNB technology is only briefly reported in most publications, thus requiring some sort of quantification methods, such as indices for formal lithic technologies as has been done, for example, in Palaeolithic research. Broadly, the principles of indices could be employed for the bidirectional blade component; however this is inapplicable for this research since the studied samples include only...