It could also be a variant on the English form which is the Spenserian sonnet, named after Edmund Spenser (c.1552–1599) in which the rhyme scheme is, a-b a-b, b-c b-c, c-d c-d, e-e. In a Spenserian sonnet there does not appear to be a requirement that the initial octave set up a problem which the closing sestet answers, as is the case with a Petrarchan sonnet. Instead, the form is treated as three quatrains connected by the interlocking rhyme scheme and followed by a couplet. The linked rhymes of his quatrains suggest the linked rhymes of such Italian forms as terza rima. This may be taking things a little too far, however.

Personally, I think Shakespeare had the right idea.