Nelson Croom's distinctive philosophy on learning design is based on the definition of two types of learning: diffused and focused.

Focused learning is concerned with a set curriculum. Learners come to a programme with similar prior experience or qualifications. They follow the same programme as the other learners and cover the same topics. This is the type of learning that most academic qualifications are based on.

But this type of learning doesn't usually address the needs of adult, professional learners. Diffused learning embraces the idea that not all learners are starting from the same place; they have different experiences, skills and knowledge. Diffused learning is designed to achieve enlightenment and learner satisfaction by meeting each individual learner's needs. The resources are learner-centred and activity-driven with measurable quantitative and qualitative outcomes.

You can read more about diffused learning in David Croom's article:

Achieving learning outcomes