Compared to the kind of research completed by Ebbinghaus, how would you characterize the studies done by Bartlett (e. g., The War of the Ghosts)

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.

answer; correlational;

answer; in small towns;