OLPC Human Interface Guidelines

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Introduction

Who Should Read This Document

These guidelines are targeted primarily at developers who are building tools for the OLPC laptop. They provide an in-depth view of the various features of Sugar, the laptop user interface, and focus closely on the parts of the UI that pertain directly to software development and the ways in which applications, embedded into "activities," interact with the operating system.

However, as these guidelines are intended to provide a comprehensive overview of the user interface, these pages should also be of general interest. Hopefully the descriptions of the various UI elements, particularly in the Laptop Experience section, will quench the thirst of all who want to better understand the project and its goals.

How to Read This Document

Undoubtedly, many who have made it to this page have read at least one set of human-interface guidelines in the past. Nonetheless, we strongly request that you read the content of this document in full. Many of the terms contained within will be quite familiar to you, however, we urge you to review them anyway, since our approach to the user experience shifts away from the traditional desktop. As such, this document may introduce some unfamiliar ideas around such otherwise familiar terms that you should consider throughout development.

While we would urge you to read this document once from start to finish, extensive use of both internal and external hyperlinking allows you to peruse its contents at will. Hopefully this will make revisiting particular parts of the guidelines quick and easy, and will allow you to move naturally through the details that pertain most to you. Additionally, where relevant we have included links to the APIs in order to make the relationship between design and implementation clearer. Please take advantage of this as you develop for the laptops.

Core Ideas

Activities, Not Applications

Though it might take a little while to get used to, there are not software applications in the traditional sense on the laptop. The user experience on the laptop focuses around "activities." This is more than a naming convention; it represents the intrinsic quality of the learning experience we hope that the children will have when using the laptop. Activities are distinct from applications in their foci—collaboration and expression—and their implementation—journaling and iteration.

Presence is Always Present

Everyone has the potential of being both a learner and a teacher. It is in order realize this potential that we have chosen to put collaboration at the core of the user experience. The omnipresence of members of the learning community will facilitate children to take responsibility for one another's learning as well as their own. The exchange of ideas amongst peers can both make the learning process more engaging and also stimulates critical thinking skills. We hope to encourage this type of social interaction with the laptops.

In order to facilitate a collaborative learning environment, the laptops employ a mesh network that interconnects all laptops within range. By exploiting this connectivity, every activity has the potential to be a networked activity. We aspire that all activities take advantage of the mesh; any activity that is not mesh-aware should perhaps be rethought in light of connectivity.

As an example, consider the web-browsing activity bundled with the laptop distribution. Normally one browses in isolation, perhaps on occasion sending a friend a favorite link. On the laptop, however, a link-sharing feature is integrated into the browser activity, transforming the solitary act of web-surfing into a group collaboration. Where possible, all activities should embrace the mesh and place strong focus on facilitating such collaborative processes.

Tools of Expression

Starting from the premise that we want to make use of what people already know in order to make connections to new knowledge, our approach is to focus on thinking, expressing, and communicating with technology. The laptop is a "thing to think with"; we hope to make the primary activity of the children be one of creative expression, in whatever form that might take. Thus, most activities will focus on the creation of some type of object, be it a drawing, a song, a story, a game, or a program. In another shift in the language used to describe the user experience, we refer to objects rather than files as the primary stuff of creative expression.

As most software developers would agree, the best way to learn how to write a program is to write one; studying the syntax of the language might be useful, but it doesn't teach one how to code. We hope to apply this principal of "learn through doing" to all types of creation, e.g., we emphasis composing music over downloading music. We also encourage the children to engage in the process of collaborative critique of their expressions and to iterate upon their expression through a process of debugging.

The objectification of the traditional filesystem speaks more directly to real-world metaphors: instead of a sound file, we have an actual sound; instead of a text file, a story. In order to support this concept, activity developers may define object types and associated icons to represent them.

Journaling

The concept of the journal, a written documentation of everyday events, is generally understood, albeit in various forms across cultures. A journal typically chronicles the activities one has done throughout the day. We have chosen to adopt a journaling metaphor for the filesystem as our basic approach to file organization. While the underlying impementation of such a filesystem doe not differ significantly from some of those in contemporary operating systems, it also holds less importance than the journal abstraction itself.

At its core, our journal concept embodies the idea that the filesystem records a history of the things you've done, or, more specifically, the activities you've participated in. Its function as the store of the objects created while performing those activities is secondary, although also important. The journal naturally lends itself to a chronological organization (although it can be tagged, searched, and sorted by a variety of means). As a record of things you've done—not just the things you've saved—the journal will read much like a portfolio or scrapbook history of the children's interactions with their machine and also with thier peers. The journal combines entries explicitly created by the children with those which are implicitly created through participation in activities; developers must think carefully about how an activity integrates with the journal more so than with a traditional filesystem that functions independently of an application. The activities, the objects, and the means of recording all tightly integrate to create a different kind of computer experience.

Design Fundamentals

Know Your Audience

Low floor, no ceiling.

Inexperienced

The goal of OLPC is to provide children with new opportunities to explore, experiment, and express themselves. Many children in need of such opportunities have previously had little or no access to computing, and so will be unfamiliar with the laptop and how to interact with it. This will undoubtedly have effects on some aspects of activity development. On the one hand, it means that developers must focus energy into making interfaces discoverable, wholly intuitive, and building metaphors that strengthen and clarify the interface. On the other hand, since the laptop will the be the first experience of computing for many children, activities do not have to be overly true to legacy behaviors or expectations. This frees developers to innovate.

Young

Many of the children who will receive laptops are just entering kindergarten. Others will be in their young teenage years. Therefore, it is important to develop activities in ways that scale across age levels.

International

The OLPC initiative, by its nature, requires international involvement and participation. Developers must keep in mind the broad range of cultures and languages that the laptops must transcend. In particular, activities should not depend on western icons and modes of thinking, but should abstract ideas to a level that would be familiar to humankind in general, where possible. For instace, consider the camera button on the keyboard. Though one might be inclined to label this key with a small image of a camera and lens, the eye graphic speaks directly to our human capacity for vision, providing a cross-cultural icon that represents the compute's ability to capture what it sees.

Key Design Principals

Performance

Usability

Simplicity

Reliability

Adaptabilty

Interoperability

Mobility

Exposability

Accessibility

Transparency

The Sugar Interface

Color

The basic color scheme for the laptop is constrained by the need to work in both color (backlight mode) and grayscale (reflective mode); thus we have chosen guidelines that ensure at least some achromatic contrast under all conditions. Further, sustained legibility of text is accomplished by a combination of colors whose achromatic contrast is large and whose chromatic energy is of low to moderate level. For this reason, we are striving for achromatic contrast of at least two Munsell value steps.