## What are good sub-questions?

It is important that there is a direct relationship between the sub-questions and the main question. For the main question,

“Which modifications to the infrastructure are needed to ensure that the growing number of tourists in Amsterdam can move around more efficiently?”

The sub-questions could be:

- What have been the effects of the growth in the number of tourists in Amsterdam on traffic flow in the last five years?
- How large is the expected growth in the number of tourists in Amsterdam for the next five years?
- Which are the main traffic bottlenecks?
- What is the design of the infrastructure at the main bottleneck locations?
- Which are the main criteria for effective traffic flow?
- Which measures relating to infrastructure have been taken in similar cities in order to make it easier for tourists to move around?

Sometimes, you can make your sub-questions even more specific, in the form of search questions. Search questions for the last sub-question could be:

- Which measures relating to infrastructure have been taken in Berlin in order to make it easier for tourists to move around?
- Which measures relating to infrastructure have been taken in Barcelona in order to make it easier for tourists to move around?