The most important people to include in the working sessions are the folks that actually have the decision-making power. This will usually be one or two main stakeholders. If the website is large and has many diverse facets, it's generally good to include a subject matter expert from each area to help facilitate discussion from someone knowledgeable in that space; however, these people are not decision-makers. While their insights are valuable and merit consideration, the ultimate responsibility for making final decisions on navigation adjustments lies with the designated decision-makers.
Adjusting group size throughout the process
While stakeholders hold the decision-making power, we remain flexible and receptive to collaborating with larger groups. Our experience has shown that presenting the original navigation to a more extensive group at a project's outset can spark valuable discussions about what works and what doesn't. After this initial information gathering, the number of people included in future exercises is usually reduced to a smaller size.
Knowing when to reveal our progress
Understanding when we should share the inner workings of a project with clients versus working behind closed doors requires a delicate balance. We rely on the client's knowledge of their users and thoughts from the users themselves, if we can get it, to know what needs to move where, but we are the usability experts and what makes good navigation. With that in mind, we utilize surveys, interviews, and various exercises to draw out that knowledge and create forward momentum. (For more information on our tool kit, check out our UX Workbook.) Exercises play a crucial role in building consensus on the direction of navigational changes and, depending on the client, can also foster a sense of active involvement in shaping the new navigation. Not all clients like this, but many do, which is a great way to boost confidence. We then incorporate their feedback, along with UX best practices and extensive research, to refine the navigation before presenting it for another round of feedback. Rarely will we ever have a live design session where they watch us make progress.