William Stiebing has been influential in his attempts to single out three defining criteria: 1) an absence of scientific methodology and proof, 2) a tendency to seek simple answers to complex problems, and 3) an ambivalent and often hostile attitude toward the scientific establishment (Stiebing 1984). (p.127)Andersson categorizes the approaches using the following image (p.128):
Andersson then points out (p.131) the classical topics of alternative archeology, ranging from Giza and Stonehenge to Chichen Itza and Carnac in France. Equally there is range of artefacts, so called "OOPAs", i.e. "out-of-place artefacts" (p.133) that hold the attention of alternative archeology, such as the Antikythera Mechanism.
Much of alternative archaeology is based on presuppositions not shared by conventional archaeologists. (p.134)
Andersson, P. (2012). Alternative archaeology: many pasts in our present. Numen, 59(2-3), 125-137. doi:10.1163/156852712X630743 (UB Wien link)