The best replacement for lecture is discussion.

The best alternatives to lecture are rated as following:
★★★★★  discussion
★★★★★  seminar
★★  tutorial
★★  speech
★  presentation
★  cooperative learning
★  hands on
★  recitation
★  active learning
★  conference
★  lab
★  lesson
★  conversation
★  talk
  facilitation
  not to lecture
  discussion college
  sermon
  hands on learning
  symposium
  workshop

Your alternative for lecture is not listed? Suggest!
Speaking about lecture, one probably shouldn't forget about lab.

Other search terms related to lecture and their ratings are:
★★★★★ lab
You have in mind a companion for lecture and it is not yet here? Propose!



Google Trends

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lecture
discussion
seminar