Yes, we should investigate the factors that influence how well it works, as the authors propose.

These authors had proposed a moving earth, which did not, however, revolve around a central sun.

"The authors propose a collaborative specialist model for science teaching."

The authors propose that this can be done in three steps.

The authors propose that a social mechanism may be responsible for the observed results.

Not entirely sure what the author is proposing "we" do.

The authors also propose that the return on investment declines with age.

This analysis is all fine but does the author propose a (viable) solution?

The author himself has proposed that it "was the first true isometric 3D game".

The authors proposed some rules about the chemical elements which could also be present in these particles.