[yuriyuri]

Originally Posted by Maxful

Thanks again, halfthishalfthat. But I think there is more to it.

Why do you think there is more to it?

This is from 国語・英和・和英・類語辞書検索 - goo辞書

しゅっ‐せき【出席】
［名］(スル)会合や学校の授業などに出ること。「クラ� ��会に―する」「―簿」⇔欠席。
In other words, you just turn up to a meeting or class etc. (Attend)

さん‐か【参加】
ある目的をもつ集まりに一員として加わり、行動をとも にすること。「討論に―する」「―者」
In other words, you join in with a gathering that has some purpose and participate in the activities. (Participation)