The sign outside the auditorium says "WELCOME SPEELERS!" (oh, the irony.)
The keyboard Arnold wants has 22 white keys and 21 black keys; a five-octave keyboard should have 36 white keys and 25 black keys, and there shouldn't be a black key between each pair of white keys.
Bob has no unibrow before he opened his eyes knowing Helga's word is "qualm".
The design for Olga in this episode is not the standard design for her that we know of.
When Helga is first seen spelling "velocipede", the medal disappears around her neck.
