STORMING: ethongraphic research? participatory design? and what about arbitrary stimulus?

I decided to start my research receiving stimuls from people words and beahviors. I was just asking to someone: what if i say watch? writing the answers on a post_it and putting these notes on their bodies. I can say this research has been useful just to know something more about people reactions and not really to discover something extraordinary about mobile phones. When I ask a question about product to someone I can see various reactions, someone tryes to say something that sounds important and someone else want to appear spontaneous. My experience (the one about putting notes on their bodies) was a play and they usually were loughing at me. I received just stimulus as the ones I can receive walking on the street of a new city like Melbourne, or going to the theatre. I'm going to create three posts asking people to insert words about my three products, maybe I can get more inputs.