. Author manuscript; available in PMC: 2013 Dec 1.

Published in final edited form as: Acad Radiol. 2012 Dec;19(12):1508–1517. doi: 10.1016/j.acra.2012.09.012

Table 2.

Lay-out of Split-Plot MRMC Study Design with Three Blocks

Block 1		Block 2		Block 3
Reader 1	Reader 2
X₁₁₁₁, X₂₁₁₁	X₁₂₁₁, X₂₂₁₁
X₁₁₂₁, X₂₁₂₁	X₁₂₂₁, X₂₂₂₁
X₁₁₃₁, X₂₁₃₁	X₁₂₃₁, X₂₂₃₁

		Reader 3	Reader 4
		X₁₃₄₂, X₂₃₄₂	X₁₄₄₂, X₂₄₄₂
		X₁₃₅₂, X₂₃₅₂	X₁₄₅₂, X₂₄₅₂
		X₁₃₆₂, X₂₃₆₂	X₁₄₆₂, X₂₄₆₂

				Reader 5	Reader 6
				X₁₅₇₃, X₂₅₇₃	X₁₆₇₃, X₂₆₇₃
				X₁₅₈₃, X₂₅₈₃	X₁₆₈₃, X₂₆₈₃
				X₁₅₉₃, X₂₅₉₃	X₁₆₉₃, X₂₆₉₃

In a split-plot reader design with G blocks, J readers are randomized to a block and N_T patients are randomized to a block such that in each block there are J/G readers and N_T/G patients. In the 3-block split-plot design illustrated here, J=6 and N_T=9; thus, two readers are randomized to each of the three reader blocks and three patients are randomized to each of the three blocks.

X_ijkg denotes the test score assigned by the j-th reader in block g to the k-th patient in block g imaged with modality i.