Promotie U. (Umut) Yalcin

Below is a brief summary of the dissertation:

Every new venture begins in uncertainty. In the earliest stages, entrepreneurs must act without validated ideas, proven market demand, or sufficient resources. Popular frameworks such as lean start-up and effectuation offer clear advice for navigating this phase: stay flexible, learn from customers, and avoid latching onto initial beliefs. Yet many entrepreneurs do not follow this advice in practice, and start-up failure rates remain high. This dissertation argues that this gap cannot be understood without looking at what happens inside entrepreneurs as they navigate the unknown.

The first study follows early-stage entrepreneurs week by week in an incubation programme. It shows that doubts about oneself resurface during idea validation, and that how entrepreneurs explain their setbacks shapes whether they keep learning or slowly disengage. The second study, a series of three experiments, shows that simple "what if" thinking helps entrepreneurs understand their customers' problems more comprehensively. Interestingly, only imagining what could have been added, rather than taken away, also leads to more novel problems. Finally, the third study develops a new theory of why entrepreneurs involve customers in such different ways, pointing to the fit between an activity and one's own motivation.

Taken together, this work underscores that equipping entrepreneurs with tools is not enough. For these tools to work, they need to be complemented with the cultivation of the necessary skills and mindsets.