Flexible Hardware Configurations for Studying Mobile Usability
Antti Oulasvirta and Tuomo Nyyssönen
Journal of Usability Studies, Volume 4, Issue 2, February 2009, pp. 93-105
Article Contents
Current setup
Our current setup consists of the following three kits (see Figure 3 for the system diagram):
User's kit. The user-worn part (Figure 2) includes the following:
- One camera holder (pole) for attaching two cameras to the participant's device. One camera shoots the display, the other looks up to the participant's face.
- A necklace-camera with a microphone
- Leather belt, the following are carried on a leather belt:
- A wireless 2.4 GHz video receiver
- A video hub that integrates all the signals to the recording device and provides adjustable voltage for the attached cameras.
- A Video HDD MPEG-4 recorder
- Three battery packs (Lithium 12V)
- Necessary cables
Moderator's kit. The environmental camera setup consists of the following:
- Three surveillance cameras
- Three wireless 2.4 GHz video senders
- Three 110-240 VAC to12 VDC power adapters
- Video statives and fixing equipment
Alternatively, a moderator-carried camera (a Sony DCR-TRV30E PAL mini-DV digital handycam, equipped with a VCL-ES06 x0.6 wide-angle lens) can be used. In addition, we have previously explored the option of hiding the moderator-controlled camera in a cell phone shell to make it less visible in public places (Figure 4).
Figure 4. One of the earlier setups had the moderator-controlled camera built in a fake shell of a mobile phone. The wire goes through the sleeve to a recorder on the waist. This solution allows for quiet, non-visible recording in public places.
Maintenance kit. The following are tools for running and preparing the tests and maintaining the setup.
- Battery rechargers
- Wireless receiver for setting up the environment cameras
- Travel cases for the equipment
The kits fit into two aluminum briefcases that can be carried to the site of experiment (Figure 5). The total worth of the current setup, including labor and component costs, is about 10,000€.
Figure 5. The whole kit fits into two aluminum cases that can be taken to the site of study. This case includes environmental cameras; the other kit contains the user-worn components.