TABLE 3.

Overview of different linking approaches.

		IRT Model		Scaling		Linking
	Method	1PL	2PL	conc	sep	Haber	chain
Without field test (all items)	C1	x		x
	C2		x	x
	H1	x			x	x
	H2		x		x	x
	S1	x			x		x
Without field test (invariant items)	C1I	x		x
	C2I		x	x
	H1I	x			x	x
	H2I		x		x	x
With field test	C1F	x		x
	H1F	x			x	x
	S1F	x			x		x

1PL = 1PL model; 2PL = 2PL model; conc = concurrent scaling; sep = separate scaling; Haber = Linking based on the Haberman method; chain = chain-linking approach. An entry in the “linking” columns is only made for the separate scaling approaches.