Final answer:
An idea that is high on value and usefulness and low on the degree of novelty is categorized as an improvement according to the Neck Idea Generation Matrix.
Step-by-step explanation:
According to the Neck Idea Generation Matrix, if Nan has an idea that is high on value and usefulness but low on the degree of novelty, the quality of this idea is improvement. The matrix suggests that ideas can be categorized based on their novelty and their potential to create value. Innovations typically involve a novel approach and create significant value, while inventions are usually very novel but might not necessarily be immediately valuable. Improvements, on the other hand, enhance or refine existing products, systems, or processes and are high on usefulness but low on novelty. This can involve making something more efficient, reducing costs, or enhancing its features without fundamentally changing its nature.