The qualitative aspect in UX/UI design focuses on a profound understanding of user needs and preferences. This encompasses behavior analysis, feedback collection, and participation in research interviews. Here, key factors include emotional reactions, experiences, and user perceptions during interactions with the product.

On the other hand, the quantitative aspect centers on voluminous data and metrics. This involves analyzing user actions using analytics tools. The quantitative aspect provides us with a digital portrayal of user-product interactions, particularly valuable for identifying trends and pinpointing areas for improvement.

The strength lies in striking a balance between qualitative and quantitative aspects. Their combination enables us to comprehend both why users engage with the product and how they do it. The qualitative aspect adds depth, while the quantitative one furnishes data volume.

Hence, it's crucial to remember that qualitative and quantitative aspects in UX/UI design are interconnected and mutually reinforcing. Employing both approaches allows for the creation of a product that combines depth of understanding with data volume, forming the bedrock of a successful user experience design.