[rusk]

I share your confusion to a degree. To me it always seemed that the concept emerged from the work on Semantic Networks [0] by Collins and Quinlan.

What's interesting is, looking at this now that these two different aspects of what we nowadays consider to be a fairly well defined computer science concept both seem to have emerged around the same time.

Could it be C & Q were inspired by the Simula guys, or vice versa maybe Simula adopted the term because the implementation "resembled" the semantic definition. Or perhaps they independently emerged from concepts that were popular at the time!

[0] https://en.wikipedia.org/wiki/Semantic_network