The CONTEXT method labels usages of an expression in a leave-one-out strategy, where each test token is labelled by using the other tokens as noisy training (goldstandard) data.
to provide gold-standard data for each instance of an expression, we first divide the other instances (of the same expression) into likelyidiomatic and likely-literal groups, where the former group contains usages in canonical form(s) and the latter contains usages in non-canonical form(s).