After its first mini-season (Season 1), the show rocketed to #1 for the next several years. However in season 7 the show fell from #1 to #12, falling out of the top 10. What caused this sudden drop? The show rebounds the following season to #4. What caused this rebound?

When I watch the show in syndication, I always watch until the kids move out. the show takes a major change not having the kids in the house. We have to wait until Mike or Gloria comes over to the house to irk Archie. IMHO this is where the show jumps the shark. It appears the people watching in real time felt the same way. The kids move out at the end of season 6. We get almost recycled scripts in season 7. Gloria has a false alarm about a pregnancy. Beverly LaSalle comes back. The only episodes that really stand out are Mike The Pacificist and The Draft Dodger.
It appears they were literally throwing red meat at the audience in season 8 which did spike the ratings: Archie gets the bar business, Edith almost gets raped, Cousin Liz, Archie joins the KKK, Beveraly LaSalle gets murdered in a hate crime, Edith and the commercial, and the biggest moment was the kids leaving the show and moving to CA. The writing worked because the show jumped right back near the top.

It got moved on the schedule to Wednesday nights, then shifted back to Saturday to shore up the aging Saturday night lineup. The next year, it moved to Sunday where CBS was building a night to follow 60 Minutes (including "Alice").

It got moved on the schedule to Wednesday nights, then shifted back to Saturday to shore up the aging Saturday night lineup. The next year, it moved to Sunday where CBS was building a night to follow 60 Minutes (including "Alice").
Yeah that probably did it. But it happened when it sort of got dumb. In the earlier years fans would have found it no matter what day. The Jeffersons had the strangest ratings. It was very high, then dropped really low but then by season 6 or so it was back in the top 10.