The investigations are based on what could be called the ‘Minkova corpus of potential OSL candidates’ (see appendix 1). Basically, it is a list of Early Middle English words whose stressed vowels were short and non-high, and which are attested in Modern English. The list was partly drawn up by Minkova herself (the words of Old English origin), and partly taken over from Bliss (1952/3) (Anglo-Norman loans). I have myself added a few random examples, which I happened to come across during my own studies. All in all, the corpus contains 428 items. Thus, although the corpus does not really exhaust the set of potential OSL candidates, it can probably be regarded as a representative sample, as it can be estimated to contain far more than 50 per cent of those OSL candidates with non-high vowels that are still attested in Modern English.

First, the items in the corpus were categorized with respect to the phonological parameters of vowel quality, the consonant following the vowel and the syllable following the vowel. Furthermore, the parameters word class and etymological origin were considered. I trusted that they included most of the qualities that might be relevant with regard to vowel lengthening. The phonological parameters include practically the complete environment of the vowels in question. Only word-initial consonants were not considered, and this was because even a first look at my data confirmed the well-established knowledge that syllable onsets do not systematically influence the length of following vowels.