At Intercom, they use a collaborative approach to user testing by carrying out evaluative research early in the product development process. They aim to get product concepts in front of users before any code is written and are trying to find the right balance between "crude but early" and "polished but late". To determine the ideal level of design fidelity, they need to identify which problem they're trying to solve: testing concepts for value, testing system design for usability, or testing usability itself. The goal is to create a research stimulus that communicates the idea being tested without unnecessary details, such as using simple text descriptions, storyboards, or landing page mockups. They also emphasize the importance of starting with the problem and aligning with cross-functional partners in design, product, and engineering. By finding the right balance between fidelity and abstraction, they can elicit accurate insights from users and build confidence in their product design direction.