This is the 7324th most frequent Korean word.
진행했던
"진행했던" means "that had been carried out" or "that had progressed."
The word '진행했던' in this context refers to research activities undertaken previously ('carried out').
우리가 진행했던 연구는 많은 데이터를 포함하고 있었습니다.
The research we carried out contained a lot of data.
Here, '진행했던' is used to describe a completed, past action of conducting a presentation ('conducted').
그가 진행했던 발표는 매우 체계적이었다.
His presentation that he conducted was very systematic.
The word '진행했던' is used here to indicate an action that was completed in the past but which is relevant to the discussion ('carried out').