This study concentrates on plant remains from three sites, Cafer Höyük in Southeast Turkey and Abu Hureyra in northern Syria, and El Kowm II-Caracol, a steppe site in the El Kowm basin, from the 8th to early 6th millennium BC (during the PPNB period), to answer questions about the nature and extent of early agriculture. Change is examined in the light of intensification, to determine whether intensification can be detected and what criteria can be used. Past work on intensification of food procurement by hunter-gatherers and traditional agriculture is reviewed, indicators of agricultural intensification are examined, and other indicators such as the evidence from bone analyses is incorporated. Other elements from the architecture and artefacts of the sites are examined to support the interpretation, together with background investigations of the present and the past environments of the sites, as well as ethnographic investigations.