Levine's equations for random groups and unequally reliable tests can be used to equate tests X and Y through performance on an anchor test, Z. Levine's derivation assumed that all three tests were parallel in function, with X and Y of different lengths. It is shown that the parallelism requirement is unnecessary, as it is sufficient to assume only that X and Y are congeneric, an assumption that is itself implicit in the definition of linear test equating.
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