koreanfestivals1-7, Exercise 1: Doljabi and the first birthday

Model answer:

Doljabi: the child is set before several objects and picks one; the choice is read as a sign of the future. Any three: books or a brush = intelligence or success in the civil exams; money = wealth; a bow or sword = martial talent; sewing items = household skills; thread or noodles = long life.

A more recent custom: the dolbanji, a gold ring, said by the article to have come from Chinese immigrants in the early 20th century (the day itself dates to early Joseon).
A change: the day is now often a secular party at a reserved venue, rather than a home ceremony with an offering to Samsin.

Sources: Wikipedia, Doljanchi.