Technician is a type of Expert. Specialist is a type of Expert. you are likely to find Specialist in/at/on Conference. Conference is related to Audience. 
Programming is related to Code. Address is a type of Code. Address is related to Envelope. 
Technician --IsA--> Expert <--IsA-- Specialist --AtLocation--> Conference <--RelatedTo--> Audience 
Programming <--RelatedTo--> Code <--IsA-- Address <--RelatedTo--> Envelope 