Regarding item (2), Salton did talk about this and many systems from the early TREC times implemented them. In my own work, I found that relevance feedback wor

Regarding item (2), Salton did talk about this and many systems from the early TREC times implemented them. In my own work, I found that relevance feedback worked very well with only a few dozen judgements. See Chapter 7 starting on page 83 in my dissertation: https://arxiv.org/abs/1207.1847 https://arxiv.org/abs/1207.1847 Note also that the evaluation of Luduan in that chapter compared against state-of-the-art (for the time) back-of-words systems but also an early word embedding retrieval system (Convectis from HNC).