The coherence principle (also called seductive details¹⁾ effect) claims that extraneous material that may be interesting or motivating but is irrelevant for learning objectives generally wastes learning resources and hinders learning of important material. This assumption is grounded in the fact that human cognitive resources are limited. Still, cognitive load theory predicts this effect will only occur if the cognitive load imposed by important learning material is high enough.²⁾

Seductive details can be³⁾:

• relevant or irrelevant with respect to the learning goals, and
• redundant or non-redundant.

Seductive details can appear in virtually any format, but most often as text.

A number of studies on the effect of seductive details have demonstrated:

• negative effects on learning of important material⁴⁾⁵⁾
• lack of negative effects on learning of important material.⁶⁾

Surprisingly, a recent study even found an large increase in learning due to seductive details.⁷⁾ Possible explanations offered for this phenomenon are:

• low cognitive load imposed by instructional material (free cognitive resources) in combination with
  • increase in motivation and cognitive engagement caused by interesting seductive details
  • enhanced mental model due to additional information which was successfully processed