Socrates concludes from the examples with arithmetic and medicine that the one who has a techne in a subject is the one who may recognize the one speaking well in the subject and the ones speaking badly (later in the argument, worse = less well), so that Io himself turns out to be the one with techne who can judge that Homer speaks well while the other poets speak less well. Socrates finally uses the word kritēs (judge), but not about those who judge rhapsodes such as Io in competitions, but about Io himself, judging Homer and the other poets. This is confusing, to say the least, and it is not clear what the techne might be which Homer, the other poets, and Io, are considered to be using.

Here I read through Platonic dialogues, translating and commenting on the Greek text as I go.

The resulting analyses may be found at:
https://theplatoparadigm.com

The full analyses include Euthyphro, Io, Hippias Minor, and Lysis, with extract/summaries from my books on Hippias Major, Meno, and Politeia (Republic)