Criticisms of introspective data

1. Naturally occurring data is observable and verifiable by everyone. Introspective judgements are unobservable, therefore much more difficult to verify.

2. Introspective data is artificial. Sampson (1992) argues that the type of sentence analysed by the introspective linguist is far away from the type of evidence we tend to see typically occuring in a corpus. By artificially manipulating the informant, we artificially manipulate the data itself.

3. Human beings have only the vaguest notion of the frequency of a construct or a word. Corpora are sources of quantitative information beyond compare. However, frequency-based data is not available via introspective means.