**3. Tools, techniques and artefacts**

Participatory design instruments, including digital and physical games, mapping instruments, and visualisation systems, are used in participatory design activities to engage stakeholders in design thinking [5]. Participatory instruments support collaborative design enquiry and bring together a network of actors with different backgrounds, competencies and experiences [6]. Ehn [7] describes a design philosophy called 'tool perspective', which suggests that computer-based tools should be designed by considering the traditional practical understanding of tools and materials used within a given craft of profession. That means the design process must be carried by the common efforts of skilled, experienced users and design professionals. The users possess the needed practical understanding of the design but lack insight into the technical possibilities. The instrument designers must understand the specific decision process that uses the tool.

Traditionally drawings, product samples, models, and now virtual 3D models are used to mediate the journey of a building concept to the actual built form. These artefacts are often produced for different purposes and obviously for people with varying understanding of the design and construction process [8]. Luck [9] argues that design practice using physical artefacts at the early stages of building design is appropriate for design conversation, as it develops users' understanding of the design. The design conversation builds the user's confidence in the appearance of the design, rather than only through the ability of the artefacts to represent a future reality. The artefacts embody the current knowledge of the design in its present status and, during a conversation, prompt discussion on ideas. Here, the 'act of interpretation' is acting as a part of the design process. In this regards, Bucciarelli [10] stated earlier that design only exists in the collective sense and is realised through conversation and action. In the same note, Luck and McDonnell [11] observe that an architect has a range of prompts and conversational repertoires to elicit information from users when discussing a design.

The studies below primarily talk about the generation of virtual three-dimensional (3D) artefacts as elements for design conversation. The current nature of

technological interfaces enables anybody to manipulate virtual 3D artefacts by simple hand device movement in virtual environment (VE). The tested instruments below can produce instantaneous 3D artefacts with perceptual understanding particular to the instrument and the design tasks.
