Quick tip: make your own iPhone usability testing sled for £5

May 7, 2010

iPhones are wonderful things for many reasons, but you can’t run screen-recording or screen-sharing software in the background during research sessions. Even if you could, it would make the device run like treacle and you’d miss out on getting footage of your user’s fingers, which is pretty important. This makes using a sled a good idea. A sled is the thing you use to mount a camera onto your mobile device in a usability testing session. It allows the user to hold the device in their hand and move it around in a relatively natural way, while ensuring the camera is always focused properly on the screen.

If you were to buy one from a lab supplier, you could end up with something heavy, over-designed and expensive – as much as $3,500 for a sled with two cameras! The fact is, you can easily avoid the cost and make your own.

I dropped in to our local plastic merchants and asked them to cut some 3mm transparent acrylic to shape and bend it using a heater strip. 24 hours and £5 later they handed me this:

iPhone Usability Testing Sled
Rough dimensions: base 5.5cm x 11cm, stem: 17.5cm x 2cm, Lip: 2cm x2cm

This is probably the most unremarkable piece of plastic in the world, but it’s cheap and it’ll save you trying to cobble something together with office equipment and duct-tape. The idea is that you mount a small webcam facing down on the top lip, and mount your iPhone on the bottom using adhesive pads (use an iPhone case if you don’t want to dirty up your device). Most modern webcams can deliver a fairly high resolution picture if you meddle with their settings, but be sure to turn on manual focus, or you’ll find the camera will keep trying to focus on the user’s fingers rather than the screen.

I use Morae to record the sessions and stream them live across our internal network. An added bonus is that Morae V3+ supports dual cameras – so you can record the user’s face picture in picture with a second webcam. A Morae license is pretty expensive though ($1,495 USD!), so if you don’t already have one, you may want to use some relatively basic recording software that simply records the video and audio feed to a file (you probably got an app bundled with your webcam). Silverback would probably work with an external webcam, though the screen recording part would be redundant- if you try it, let me know how that goes.

(8-May-2010) Edit: more tips!

You’ll see in the comments below that Nick Bowmast has added a couple of really useful tips. Firstly, you can use a rectangular piece of acrylic and bend it to shape over a household toaster, which means you can easily do it at home and you don’t need to bother even cutting the acrylic to shape. Secondly, if you don’t mind using an analog camera with RCA connectors, you can use a micro CCTV camera.


Image credit: Nick Bowmast.


Image credit: Nick Bowmast.

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