Donald Davies' work caught the attention of ARPANET developers at Symposium on Operating Systems Principles in October 1967. He gave the first public demonstration, having coined the term "packet switching", on 5 August 1968 and incorporated it into the NPL network in England. The NPL network and ARPANET were the first two networks in the world to use packet switching, and were themselves interconnected in 1973. Roberts said the ARPANET and other packet switching networks built in the 1970s were similar "in nearly all respects" to Davies' original 1965 design.