Converted using Latex2HTML Page 1 2
Michael J. Mahemoff
Department of C. S.& S. E.
The University of Melbourne
Parkville, 3052, Australia
m. [email protected] csse. unimelb. edu. au
Tel: +61 3 9344-9100
Fax: +61 3 9348-1184
Lorraine J. Johnston
School of I. T.
Swinburne University of Technology
Hawthorn, 3122, Australia
[email protected] swin. edu. au
Tel: +61 3 9214-8742
Fax: +61 3 9214-5501
KEYWORDS Pattern Languages, Design Reuse, Internationalisation, Usability.
Planet: An Overview
Software is becoming an increasingly international affair. The internet has brought users closer together,
and there is more outsourcing to overseas firms than ever before . Since good software takes into ac-count
the characteristics of typical users, internationalisation produces challenges because of user diversity.
The Planet pattern language aids in the specification of such systems, with a goal of making them usable
and useful to people from different locations and backgrounds.
The overall process for producing software which fits the needs of particular cultures is termed cul-turalisation
(after ). It is not enough to provide one global version of software with the intention of
satisfying everyone. Some software features, such as images and text, must be developed with specific cul-tures
in mind. To this end, the culturalisation process entails two phases. In the internationalisation phase
(also called localisation-enabling), databases and other structures are set up within the core system. These
structures are then populated in the localisation phase, when programmers, translators, graphic artists, and
others decide what is appropriate for a particular user community.
Figure 1 provides an overview of the fourteen patterns and indicates the seven patterns we have de-tailed
in this paper. The remaining patterns are summarised in Section 8. The cycle between Flexible
Function( 4) and Elastic User-Interface( 5) reflects the idea that functionality and user-interface
should be iterated until satisfactory.
You begin applying the language when you have been presented with a project that delivers to multiple
cultures, or may do so in the future. In this case, begin with Export Schedule( 1). If there are no such
projects, but you anticipate they will come later on, you can get started by developing some Culture
Copyright c 1999, The University of Melbourne. Permission is granted to copy for the PLoP 1999 conference. All other rights
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User Interface( 5)
Figure 1: A map of the Planet language. The number after some patterns represents its position in this
document. Section 8 outlines the remaining patterns.
1 Export Schedule
Context: You are beginning a project where users will come from a wide range of cultural backgrounds.
Problem: Culturalisation is a resource-intensive exercise.
How can you allocate resource to cultures at a level befitting their individual needs, and at the
same time ensure that no more attention than necessary is devoted to any particular culture?
Forces: You should know which cultures will use your software, otherwise you cannot provide features which meet their needs.
It is often too expensive to produce for all audiences at the same time. Sometimes, a local version is prepared first and overseas users are considered later on.
Introducing a new culture may not be a simple localisation procedure. The new culture may ne-cessitate changes to the internationalisation framework and this can be painful. As one example, different cultures use different rules for sorting words. An English-language implementation
can sort using the " " and " " operators, but what if a culture with a different alphabet order
is introduced? If the comparisons are scattered across the code, then a programmer will have
the unenviable task of replacing each one with a generic comparison function.
Solution: Produce a schedule which indicates when each target culture will be supported, and how
important it is to support each target culture. Some cultures will not use the system until version
3.0 is released, but these cultures should still be considered when version 1.0 is developed. The
repository can be consulted to determine which factors vary across the supported cultures. The
localisation phase can then address this variation.
In most businesses, interaction with the marketing department will be essential. When considering
attractiveness of foreign markets, consider size and value of customer demand, competitive import-ance
of the market, and availability of expertise .
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At this stage, establish the importance each culture places on different aspects of software. For
instance, Evers and Day  found that Indonesians, compared with Chinese, are more attracted
towards usability than certain other qualities. Since you cannot maximise every quality, this kind of
information will tell you which areas to focus on for a given culture.
Rationale: Identification of cultures in advance ensures that the functional core and internationalisation
framework are flexible enough to make changes relatively straightforward.
Examples: Searching for target markets, choosing how intensive the operation will be, and planning future
expansion is a well-established international marketing practice .
Uren et al.  suggest that marketing staff should develop a list of target countries, even if transla-tion
is not immediately required. Luong et al.  suggest that developers need to decide between a
full localisation and a partial localisation, and also consider whether to ship overseas simultaneously
with the local release.
Resulting Context: If your organisation has not already done so, start creating Culture Models( 2). You
may need to update existing Culture Models( 2) to reflect any new cultures being considered or to
account for aspects of the cultures which are relevant to the new project. Once you have collected
Culture Models( 2) into an Online Repository( 3), you will be able to create a Multicultural
System suitable for cultures mentioned in the schedule.
Note: For the remainder of this paper, the cultures mentioned in the Export Schedule( 1) are
referred to as Target Cultures.
2 Culture Model
Context: You are working on software projects with Export Schedules( 1) identifying which cultures
will use the system.
Problem: Like beauty, usability and utility are in the eye of the beholder. You have to understand the user
before you can begin working towards these qualities. How do you support development decisions
which depend on information about specific cultures?
Forces: Extensive information may be required to support development decisions, necessitating poten-tially
expensive research activity. This effort will have to be repeated on new projects involving
the same cultures unless explicit attempts are made to reuse it.
It is difficult— sometimes impossible— to reverse-engineer details about cultures just by look-ing at the resultant product. The Walkman has been successful in America largely due to the fact that people do not want to be disturbed by the outside world, but it was originally conceived
by Sony's co-founder to help listeners avoid disturbing others .
Even if you can access process documentation such as meeting minutes, information about cultures will be scattered. This will be difficult to find specific information when it is needed during internationalisation and localisation.
Solution: Construct models of cultures which are relevant to your projects. When you discover new
information about a culture, add it to the culture model. To improve opportunities for reuse,
these models can be held in common by the entire organisation, rather than pertaining to a specific
project. They are an asset which is refined over time, just like a software library or an estimation
The culture model can also include issues regarding the development process. Luong et al.  dis-cuss
the English-language ability of the quality assurance engineers they deal with in Japan. Another
culture-dependent process is user testing; some cultures are more reluctant than others to criticise a
product (e. g. ).
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Rationale: Consistent culture models provide a central point for culture-specific details and also help
developers compare and contrast cultures. If a developer notices that all of the cultures for a particular
program use Latin characters, then the internationalisation phase need not consider the possibility of
non-Latin character sets. Localisation will also be more efficient if similarities between cultures can
Examples: There are several well-known culture models in anthropological and marketing literature. In
"Understanding Cultural Differences" , Hall and Hall explain several culture-dependent vari-ables,
e. g. the level of detail people desire when presented with information, attitudes to personal
space, whether or not people like to perform tasks in parallel.
Luong et al.  provide details on localising for Asia. Numerous business texts describe the
intricacies of doing business with, or creating products for, a particular country  or region .
Resulting Context: Once you've decided to create a culture model, you'll need a way to structure it. A
culture model can be conceptualised in different ways; an extremely simple form is just an arbitrarily-ordered
collection of relevant documentation gathered from various projects. In this pattern language,
we focus on one means of characterising a culture: the Vector Metamodel form.
3 Online Repository
Context: You have begun to maintain Culture Models( 2) according to the same Vector Metamodel
(i. e. same factors for each culture).
Problem: As you start accumulating Culture Models( 2), you will realise the need to organise them
together. How can a collection of culture models be organised in a manner which is useful for
Forces: Culture Models should be organisation-wide to avoid duplication; it is feasible and desirable to transfer information learnt from one project into other projects.
Information about cultures should be shared, but is often discovered in physically-distant loca-tions.
If developers can't access the models quickly and easily, the information will be ignored.
If developers can't update the models easily, the repository will lose accuracy over time.
Cultures have relationships with one another. We should be able to capture associations, such as one group being a sub-culture of another group.
It is useful to look up a specific Culture Model( 2), but there are many other ways people might like to access information during the culturalisation process. Depending on the task at hand, developers may wish to explore the information in unanticipated ways, e. g. comparing
two cultures, considering a single factor across numerous cultures.
Solution: Create an online repository, accessible to the entire organisation. Compose it of Culture
Models( 2) all based on the same Vector Metamodel.
The following guidelines make it easy to access information in the repository:
Provide browsing facilities which present each culture and factor. Let the user select a factor (and show how each culture varies on it), a culture (and show all of its factors), or a combination of both.
Provide facilities to search the Culture Models( 2).
Link from one model to another if it helps to demonstrate a point of similarity or difference.
Link to the original artefacts if they are online, or identify the source if they are not. The following guidelines make it easy to update the repository:
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Facilitate discussion among contributors, e. g. via a mailing list or within the repository system.
For each Culture Model( 2), make one or more people responsible for maintaining it. Large repositories can group Culture Models( 2) together, e. g. according to continent. This ap-proach
can follow the Composite pattern , e. g. a model of Europe contains its own information
and also contains child models (France, Italy, etc.). When a user looks up a model, information about
its ancestor models are also shown.
Rationale: Like pattern languages, repositories of this nature help people reuse existing, tested, know-ledge.
Reuse of proven concepts involving human-computer interaction are particularly helpful,
because people's reactions can be difficult to predict. In the case of interaction with international
systems, the case for reuse is even stronger, because more work is required to obtain original know-ledge
(e. g. travelling overseas, establishing partnerships with foreign consultants).
Examples: Fernandes  contains some tables showing factors versus culture. However, the text stops
short of exhaustively listing this information. One table might show cultures A, B, and C, and a table
on other factors might show A, D, and E.
Ito and Nakakoji have prototyped a system for retrieving culture-specific details .
The authors are currently undertaking a project to build a web-based repository. The intention is that
developers and users from around the world will use and contribute to the database.
Resulting Context: The repository enables developers to easily access a corpus of culture-specific inform-ation.
You can use this information to specify a Multicultural System.
4 Flexible Function
Context: You are producing a Multicultural System and an Online Repository( 3) has been estab-lished.
You have begun to specify the user-interface according to Elastic User-Interface( 5) or
you feel that it is more appropriate to specify functionality before the user-interface.
Problem: A culture-sensitive user-interface may contribute to usability, but it is still possible that the
software does not support the tasks users would like to perform, i. e. lacks utility. These tasks and
the context in which they occur can be related to culture.
How do you ensure the software performs functions which are meaningful and useful to people
from different cultures?
Forces: Software is typically written with specific domains in mind, whether broad (e. g. a spreadsheet) or narrow (e. g. a code inspection tool).
Domains— whether broad or narrow— are not homogeneous with respect to culture.
Usability is also influenced by the user's culture, and usability derives from more than just the user-interface. Flexible searching, for instance, cannot be achieved just by applying Elastic User-Interface( 5).
Solution: When you generate a new function, check if it is culture-specific, and if so, refine it to meet
the needs of your target cultures.
Break the requirements phase into several smaller stages. This way, you can progress incrementally,
so that planning for the subsequent stage can take into consideration the cultures mentioned in the
Export Schedule( 1). Whenever you create a new requirement or refine an existing one, consider
its impact on the target cultures. Some cues which might suggest culture is an important factor
a requirement depends upon legislation (a taxation rule).
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a requirement implies an organisational role (only certain people are authorised to shut down the assembly line).
a requirement is based on a philosophical stance (a teacher can annotate text, but students can't ).
a requirement is underpinned by certain ethical values (an employee's actions will be logged). This process may generate new questions about cultures which the repository should be consulted to
solve. If it cannot solve them, seek the most important answers by alternative means (e. g. interviews
with domain experts) and update the repository. Once the answers to these questions are known, you
will be in a better position to refine the requirements. Your initial idea for a requirement may form
the basis of a suitable default, but you may need to extend it to satisfy all target cultures.
Examples: Time-keeping variations imply more than just differences in user-interfaces. Each supported
calendar format requires functionality dedicated to handle standard operations (e. g. finding weekday
from date, incrementing date). The situation becomes even more complex when differences in other
areas, like timezones and work cycles, are considered.
Currency differences can lead to complicated functionality, especially when conversions are required.
The introduction of the Euro is a familiar example.
Nielson discussed a French educational product which enables teachers to annotate poems .
He noted that in some countries, it would more appropriate to give students the same ability. The
decision to include this kind of functionality rests on cultural values such as attitudes to learning and
Resulting Context: Iterate between this pattern and Elastic User-Interface( 5). until you are satis-fied
with functionality and user-interface structure. Establish a Universal Default( 7) for each
function in case the user's culture has not been specifically catered for.
5 Elastic User-Interface
Context: You are producing a Multicultural System and an Online Repository( 3) has been es-tablished.
You have a solid understanding of general functionality after applying Flexible
Function( 4), or you feel that it is more appropriate to specify the user-interface before concen-trating
Problem: The same functionality can be presented to the user in different ways. How do you create a
user-interface which can be used easily and effectively by all targeted cultures?
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Forces: Different cultures use different schemes for representing information. Text direction, for ex-ample, can be left-to-right, top-to-bottom, right-to-left, and even circular. Relative positioning
of graphics and highlighting mechanisms also vary .
Some cultures want more information, or different information, than others. Some cultures are more accustomed than others to inferring missing details . Cultures may also vary in the nature of information required. The right feature cannot just be plugged in later on (e. g. a
culture-specific icon or language-specific string).
Human-human interaction varies considerably across cultures. Some notions of interaction are relevant to the human-computer dialogue, e. g. reactivity versus proactivity exhibited by participants.
Solution: Design the overall structure for the user-interface flexibly, so that GUI elements can sub-sequently
be re-defined and rearranged without massive design changes.
The precise details about what information you are presenting, and how it is arranged will not be-come
clear until the localisation phase. Therefore, develop an elastic user-interface so that the user-interface
is not fixed during the internationalisation phase.
As with Flexible Function( 4), break the user-interface specification process into several stages,
so that you can plan each subsequent stage in the light of the cultures being targeted.
Two general guidelines apply:
Consult the repository or use other means (e. g. user testing) to discover how elastic the user-interface structure must be. A culture's writing direction can indicate the order in which ma-terial of a non-textual nature is also perceived. Also, text size will vary due to variations in
alphabet, word lengths, grammar, and conventions. This will affect the space allocated for
Once the overall structure is present, you will have identified the GUI elements. However, the precise details of GUI elements depend on culture. Therefore, at this stage, identify which GUI elements are culture-specific and leave them abstract, e. g. a button to delete a file could be
called delete-file and its type simply declared as a button with a bitmap and a label. After this
pattern has been applied, an artist performing localisation might create a cross for one culture
and a skull-and-crossbones for another, with accompanying labels in the appropriate language.
Rationale: Complicated changes to the user-interface, such as reversing order of elements, can necessitate
widespread code changes if they are not designed for. Also, a common problem is the introduction of
a language with text too large to fit in its usual location (e. g. a menu bar or dialogue box) . This
would be fairly trivial to prevent if it was known that the language was scheduled for introduction.
According to the Slinky meta-model , it is possible to split user-interface, human-computer dia-logue,
and functional core. Architectures based on Slinky should provide adequate support for de-velopers
who wish to create Elastic User-Interfaces( 5). Coldewey's "User Interface Soft-ware"
pattern language also covers separation of user-interface and domain .
Examples: Some programs enable text to be shown and inserted in right-to-left as well as left-to-right
modes. Farsi support within the VIM text editor lets users dynamically switch between orientations,
and can simultaneously show one file in two different windows presented in separate orientations.
The web supports various layouts. Horizontal orientation of layout (e. g. whether links are on left
or right) is correlated with the orientation of text in the originating country . It is worth noting,
though, that an individual site generally does not provide more than one layout.
Resulting Context: Iterate between this pattern and Flexible Function( 4) until you are satisfied with
functionality and user-interface structure. You can design specific features according to Targeted
Element( 6). Establish a Universal Default( 7) for the UI structure in case the user's culture has
not been specifically catered for.
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6 Targeted Element
Context: You have prepared an Elastic User-Interface( 5).
Problem: How can you create specific elements to plug into the user-interface framework?
Forces: The purpose, state, and workings of a user-interface element should be clear from its appear-ance.
A user-interface element's appearance can be misinterpreted if the user's culture was not con-sidered in designing it. An extreme case is when users are presented with foreign languages, but there are more subtle instances. The famous Macintosh trashcan looked like a postal box to
Britons, causing great frustration when they tried to e-mail their work !
It is also possible for a feature to be correctly interpreted, but still be inappropriate. Many applications use hand gestures to represent certain concepts, but some of these are offensive in some countries . Similarly, a given colour can convey different moods, depending on the
culture in question .
Solution: For each abstract element contained in the Elastic User-Interface( 5) specifica-tion,
provide an instantiation targeted to each culture in the Export Schedule( 1).
The Online Repository( 3) can be consulted for guidance. If it proves insufficient, investigate
further and remember to feed results back in to the repository for next time.
Many elements will have a common instantiation for an entire group of cultures. This is where the
idea of composite cultures discussed in the Online Repository( 3) can be useful. For instance,
a group of cultures called "English-language" can share the same text (of course, this would be a
compromise because it is preferable to have "USA-English", "UK-English", etc.).
The Online Repository( 3) can help to identify features which are misleading or offensive. How-ever,
user testing is also essential since people from external cultures can overlook this kind of
Examples: This pattern is exemplified by any software which supports different languages, address
formats, units of measurement, currency, etc. Tools and libraries like Java's MessageFormat class
support the corresponding development process.
The culture-specific partners of the Yahoo! website are another example. They are organised in the
same way as their parent, but contain information specialised to their culture, such as weather for
certain cities and status of local stockmarkets.
Resulting Context: Adopt a Language Policy to help you decide which languages will be supported and
to what extent. If your user-interface contains metaphors, ensure they are Meaningful Metaphors.
Since it can be expensive to target every element to every culture, provide a Universal Default( 7)
in case the user's culture has not been specifically catered for.
7 Universal Default
Context: You have prepared functionality and the user-interface according to Flexible Function( 4),
Elastic User-Interface( 5), and Targeted Element( 6).
Problem: Localisation is costly and requires substantial knowledge about target cultures. Providing many
features for many cultures can lead to work in the order of n 2 . How do you optimise resources when
there are many features (functions, user-interface arrangements, user-interface elements), each
of which depends on a wide cross-cultural base?
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Features should generally be tailored, because a single version of a feature is rarely adequate for all cultures. If the single version is targeted to one culture, other cultures may suffer; if the version is intended to be universal and not belong to any particular culture, it may be too
general and suit no-one at all.
Tailoring software features to a culture is an expensive, time-consuming activity. It may involve extensive research and requires local experts.
It is not always feasible to tailor software for small cultures or to cultures which have unique needs which are difficult to implement.
An Export Schedule( 1) cannot always correctly anticipate which cultures will use the soft-ware. People from unsupported cultures might move to targeted areas or download software from a website.
Solution: For each culture-dependent feature, make a default which is universally meaningful. The
aim is to a fallback setting in case nothing has been tailored for some cultures. This will never be as
good as a tailored feature, but it is better than producing a default which does not consider the cultural
issue at all (e. g. one which is only suitable for the developer's culture). The following guidelines
Provide text in the most familiar language among supported cultures.
Endeavour to produce images which are easy to understand and free from cultural bias. Since not everyone will know the most familiar language, try to replace text, e. g. button labels,
with meaningful images.
The familiar language may still be non-native for many users. Avoid the use of jargon and concepts which would only be familiar to a small subset of supported cultures.
Avoid concepts which might offend some cultures. Rationale: This pattern resembles the na ¨ ive approach to culturalisation which claims that we should
simply provide universal features. The difference here is that the pattern is seen as a fallback to help
reduce development effort, and is certainly not claimed to be ideal from the user's point-of-view.
Examples: Numerous websites provide versions in two languages: one in the native language and one in
English. English is being used as the language which will reach the most people.
Some icons and metaphors from popular software paradigms are well-understood in different cul-tures.
Web browsers often use left and right navigation arrows. Word-processors and painting pro-grams
use a blank page to represent a new document and scissors for cutting. Help is often repres-ented
by a question-mark.
Resulting Context: There is now a default for each user-interface feature, to account for cases when the
user's culture has not been specifically catered for.
8 Remaining Patterns: A Summary
The following is a summary of patterns which were not covered above.
Vector Metamodel Determine the dimensions of cultures that interest you, and characterise each Culture
Model( 2) as a vector with a value for each dimension.
Multicultural System Identify culture-dependent features of the functionality and user-interface. Create
an appropriate form of each feature for each target culture. Package the various forms together
according to All-In-One.
Language Policy Form a policy explaining to what extent each culture will be supported, i. e. how much
will be translated to the culture's primary and/ or secondary languages.
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Meaningful Metaphor Since metaphors should relate to everyday experience, tailor metaphors to meet
All-In-One To avoid stereotyping users and ensure the software is flexible, produce one version with all
forms of all features, so the user can tweak settings to their own needs. To accelerate the process,
provide a profile of default settings for each target culture.
Citizen ID To decide which cultural profile to use, determine the user's culture on first use and ensure the
choice persists until the user changes it.
Simultaneous Feature To support domains or users which deal with more than one culture, present a
feature in more than one form at the same time.
9 Concluding Remarks
The Planet language is intended to spark a few thoughts in the minds of developers about what it means to
create a truly international application, as opposed to one which is simply multilingual or culturally-neutral.
The language can be expanded in at least two directions. Firstly, Planet helps users but confronts
developers with a more complicated development context. We have commented on technical details occa-sionally,
but only to justify the efficacy of some of our patterns. It would be useful to develop a pattern
language which encapsulates the complex details of issues such as language translation and time conver-sions.
A second expansion would be broadening the domain from single-user applications to encompass
Computer-Supported Collaborative Work (CSCW). When computer systems are used to mediate inter-action
among humans from different cultures, a whole new set of challenges open up . At this stage,
we have deliberately avoided such complications. The patterns here would still be relevant, but numerous
additions and modifications could also be expected.
The authors would like to thank Todd Coram, whose many insightful comments throughout the shepherding
process led to a greatly-improved structure and description.
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