Any other nobles are too far from the teacher to follow his instruction. However, it is often difficult to coordinate this when arranging teaching between multiple players. The rules for teaching are a compromise so that players aren't punished for simple mistakes in timing or order. The plus in this example indicates the teacher, the asterisks indicate students who benefit from his teaching. A source of instruction is required to learn a category skill.
Instruction speeds the learning of teachable subskills.
If instruction in the category skill for a teachable subskill is available, then the student will learn the skill in half the normal time. If instruction in the specific subskill is available, then the student will learn the skill in one-quarter the normal time. If a noble studies this skill without any instruction, it will take him two weeks of study to learn the skill. Instruction has no effect for unteachable subskills or guild skills. In some cases, a noble may have more than one source of instruction available.