1. A method comprising: obtaining, during an unsupervised classification phase of a spoken dialog system, a semantic classifier input and a corresponding label attributed to the semantic classifier input; determining, via a processor, whether the corresponding label is correct based on logged interaction data, to yield a correctness result, wherein the logged interaction data comprises: data describing user speech; a non-speech user action indicating one of a negative training example and a positive training example; and an input/output pair having an input and an output, the input comprising a speech recognition result in a lattice form and the output comprising one of an outcome of a call, a confirmation by a user, and a call hang-up, the output being a result of the input; generating an entry for an adaptation corpus based on the correctness result; and adapting operation of a semantic classifier based on the adaptation corpus.