Developer Labs

Project Sunflower: Kindle DX Usability Study

Project Sunflower: Kindle DX Usability Study

The Kindle DX is the only dedicated eBook reader from the devices we are using for the study. It has an E-Ink Pearl display and was made with the sole purpose of comfortable and convenient reading. The first generation Kindle had a big launch in 2007, where all the Kindles were sold out in five and a half hours. The Kindle stayed out of stock for five months. These figures tell a lot about its popularity and people’s interest in reading on the device.

We studied the Kindle from point of view of academic text. We studied the reading experience on Kindle DX, the user interface it offers, and the device in general.


The users were really happy about the fact that it was lighter than any other tablet they had held in their hands.  The fact that it is lighter than most other devices is true, however saying its weight makes it an ideal eBook reader is not. The users did have problems with the weight of the Kindle DX. Some users that had used other Kindles previously said that the bigger screen on the  DX was a great advantage, but the addition to the weight worked against that. The users were comfortable using the smaller Kindle than buy the more costly, heavier Kindle DX for a bigger screen.

The E – Ink Pearl display made a mark on all users. The users were very impressed with the fact that there was no glare from the screen, and the absence of brightness adjustments to be made to the screen to adapt to ambient light.  The screen was perfectly readable in varying lighting conditions. The screen felt good, and mimicked paper.

The problems mostly faced were with the buttons on the device. Users complained the keys on the keypad were too small, and found holding the device and typing at the same time uncomfortable as the keypad was too low on the device. The fact that there are no dedicated numeric keys added to this factor. The 5-way stick was difficult to identify for the first time, and making selections was difficult until the users realized the 5-way stick could be pressed in to make a selection. The device has navigation buttons on the right side only, which makes it mandatory for people to hold the device either in the right hand, or use another hand to flip pages when holing it in the left. The ‘Back’ button and the button to navigate through a book were misleading. Users mistook the ‘Back’ button for page navigation, however it is for navigating through and to menus and not for in-book navigation. Some users also expressed the need of a ‘Forward’ button as the slow response rate may cause repeated actions causing unwanted results. The Menu button was also misleading. as users thought they could change settings in-book using the Menu button. There is a dedicated key for settings on the keypad. This key too, is difficult to identify the first time.

User Interface

The users liked the simplicity of the UI, as all the books were displayed on the Homescreen. This made it very easy to find a required book on the device.

The Kindle offered a number of font sizes to aid the user. It also has a text-to-speech feature. That being said, the text-to-speech isn’t as advanced as one might expect. It is like any other text-to-speech software you may have tried using. The software  sounds fairly automated and loses expressions, which are key to any book or story alike.

The fact that it was not a touchscreen and did nothing but read eBooks was seen as an advantage. The lack of a touchscreen and other features caused less distractions to users and readers spent time reading instead of anything else.

The main concern shown by all users was the responsiveness of the UI. Common tasks like unlocking the device, opening a book and flipping a page took a long time due to the slow refresh rate. Talking from an academic texts viewpoint, fast refresh rate is one of the most important attributes an eBook reader should possess. When reading textbooks, most people flip through chunks of pages to retrieve relevant information. A task that seems impossible at a very slow refresh rate.


The Kindle is great for linear reading, but its currently not suitable to be used to read academic text. The refresh rate is too slow to allow for fast flipping to and from pages. The limited illustrations rendering capabilities and weight are also a problem. The Kindle, due to its low weight and E-Ink display may be really well suited for leisure reading, but it might take some time till one can use the Kindle DX to replace textbooks.