Three out of the four participants interviewed during stage one took part in two prototype testing interviews. The first involved one participant and the second included two, allowing greater inter-participant discussion. The prototype testing interviews first involved showing the participants the speculative ad for Social Bubble that explains the mission statement and set-up process.

Next, I facilitated an interactive talk-through with the participants as if they were getting signed up for a Social Bubble account. We were able to discuss their decision making around why they would select certain brands, charities, and personal details to share within the browser add-on. Following this process, we engaged in a more general discussion surrounding how Social Bubble could help build trust, protect privacy, and allow for personalisation controls. This included following up with participants' perspectives from the first interview stage and allowing them to judge how well the prototype addresses them.