What model suggests that learning efficiency is determined by the ratio of effort needed to effort spent?

Carroll's Model of School Learning specifically addresses the relationship between the effort a student puts into learning and the resulting efficiency of that learning. In this model, learning efficiency is conceptualized as the ratio of the time spent on learning to the time required to learn effectively. The model emphasizes that both the amount of time and the quality of student engagement are critical factors in determining how well a student learns.

By proposing that effort (which encompasses time and engagement) directly impacts learning outcomes, Carroll's model highlights the importance of managing both time and cognitive resource allocation in educational settings. This focus on efficiency supports educators in designing effective learning environments that maximize student success by encouraging optimal effort relative to expected outcomes. The other choices do not specifically frame learning efficiency in these terms, making Carroll's model uniquely aligned with the concept described in the question.