Levengood’s Crop-Circle Plant Research

Joe Nickell, Skeptical Inquirer 20, no. 2 (1996): 19–21 — the principal published skeptical critique of the Levengood residual-anomaly research. Nickell, the Committee for Skeptical Inquiry's senior research fellow, argues that substantial methodological concerns (selection bias in case choice; soil sampling methodology; statistical controls; the substantial distinction between authentic anomalies and broader sampling effects) undermine the strong residual-anomaly claims. The article is one of the principal published skeptical engagements with the BLT research framework.