**Abstract**
![enter image description here][1]
The challenge of raising a creative question exists in recombining different categories of knowledge. However, the impact of recombination remains controversial. Drawing on the theories of knowledge recombination and category spanning, we claim that the impact of knowledge spanning on the appeal of questions is contingent upon questions’ knowledge hierarchy in the knowledge space. Using word embedding models and network analysis to quantify knowledge spanning and knowledge hierarchy respectively, we test our hypotheses with the data collected from a large online knowledge market (N = 463,545).
[1]: https://user-images.githubusercontent.com/543384/229044890-9fcb46be-7da5-4614-afd7-091e2f73bf99.png