A CORPUS OF DESIGN GUIDELINES
FOR ELECTRONIC COMMERCE WEB SITES
Costin Pribeanu, Céline Mariage and Jean Vanderdonckt
National Institute for Rearch and Development in Informatics, Bd Averescu 8-10 – R-71316 Buccharest, Romania Pribeanu@acm – /chi-romania/pribeanu/index.htm
Université catholique de Louvain, Place des Doyens, 1 – B-1348 Louvain-la-Neuve, Belgium
vanderdonckt@isys.ucl.ac.be – www.isys.ucl.ac.be/bchi/members/jva
ABSTRACT
Designing and evaluating the usability of electronic commerce web sites is a rather complex activity that involves design knowledge. One particular form of this knowledge consists of design guidelines, which can ensure some minimal form of usability. However, the guidelines are widespread throughout the literature and expresd in various forms. This paper attempts to provide a framework for structuring guidelines, exemplifying it for electronic commerce web sites.
1. INTRODUCTION
A design guideline for an interactive system consists of a widely accepted principle that ensures some form of usability of the ur interface (UI) of this system. For more than fifteen years, guidelines helped designers to improve the UIs by relying on the statement of the guidelines. However, guidelines suffer from drawbacks such as (Bastien & Scapin, 1993): widespreading throughout literature, inconsistent vocabularies, homogeneousness of sources and disciplines, potential conflict, and lack of structure. In this paper, we attempt to improve the structure of design guidelines by reporting on a template for structuring guidelines and by exemplifying it on electronic commerce web sites. It is expected that guidelines structured according to this approach will be more easily communicated to designers, understood by developers, and propagated throughout the interested organizations.
2.TEMPLATE FOR STRUCTURING GUIDELINES
The propod template for structuring guidelines consists of a list of attributes (table 1) bad on a general guideline model refined by trial and error (Vanderdonckt, 1999) and expanded to consider modern guidelines. In this table, the rows in gray are not implemented in our current databa, but ar
e encoded in the field Comment. Fields marked with an asterisk means the following: in order to ensure some consistency over the guideline collection some explanations, procedures and a list of possible values (where appropriate) are given in this guide. A subt of the attributes is defined afterwards. An entity-relationship model was defined in order to implement a guidelines ba (figure 1).
The guideline identifier is an alphanumeric identifier denoting the position of the guideline in the ction guide. It is not known at the moment when guidelines are collected. However, if the collection is structured in ctions, the number of the guideline within the ction should be provided.
The guideline title is a brief and reprentative ntence using an active verb. It is strongly recommended to be as short as possible provided that the guideline meaning is prerved. Examples of titles are: Provide on-line shopping carts..扇贝单词
The statement describes the principle that should be followed when designing the interface, for instance: Provide means to create on-line shopping carts that help urs to keep track of what they already bought.
For each guideline a list of bibliographic references quoting the guideline should be provided. The ref
erence specifies the author name and the year, for instance: [IBM00-2] IBM ea of u: “Web design guidelines” ction: e-commerce topics. Product information. /ibm/easy/eou_ext.nsf/Publish/615
No Attribute name Definition Status
国内上网课不影响学历认证
1ID_Guideline an alphanumeric identifier denoting the position of the guideline in
the all library; is an AutoNumber simple mandatory
2Title a brief and reprentative ntence written in a simple ntenceflash是什么意思
style: {[condition(s)], {imperative verb | {subject, active verb},
object complement}}; must appear on one screen line simple mandatory
3Statement a complete statement written in a natural language (preferentially in
the same title ntence style) describing the guideline, in particular
how to apply it simple mandatory
4Rationale one or many ntences explaining why the guideline is important simple
facultative
5Exception one or many ntences explaining possible exception cas with
reference to negative or positive examples multiple facultative
6Comment in his field can appear any other information about the guideline,
which is not covered by the template fields, in particular
information from the entire ERA schema; temporally the
information in grey from this template might appear simple facultative
7Reference a list of bibliographic references quoting the guideline (author(s),
year, title)multiple facultative
8Criteria criteria respected by the guideline; u elementary criteria’s;
preferentially one ergonomic criteria might be cho multiple facultative*
9Linguistic Level linguistic level in which is situated the guideline simple
facultative*
10Example example depicting a UI violating the guideline: textual explanation;
picture; reference; original web address; local directory / file
the example is positive or negative (Ill_type), normal or exceptional
(Ill_Statut)Multiple facultative
11Relationship relationship established with other guideline according to a link梦想高中
typology
to be specified: the guideline source and the guideline destination of
英语读书报告
the relationship multiple facultative
13GlossaryWord words defined for the indexation of the guideline; supertype of
Eval_Method, Criteria and Ling_Level multiple facultative
14EvalMethod methods for the evaluation of the guideline multiple
facultative 15UI type the ur interface type for which the guideline is valid: web, textual,
graphical, vocal, tactile, virtual; can be more than one
---
16Development
pha a t of phas to whom it might concern: requirements
specification, design, implementation, evaluation, training
(education) ; can be more than one
---
17Activity domain the activity domains the interface are targeted to and which may
benefit from the guideline; can be more than one
---
18Task Ur’s tasks that benefit from the guideline; tasks are meaningful in
the activity domain; can be more than one
---
Table 1. Template for structuring design guidelines.
Figure 1. Entity-relationship model of the guidelines ba.
According to Nieln (1986), the linguistic level to which the guideline is applied can be one of the fol
lowing: goal, pragmatic, mantic, syntactic, lexical, alphabetical, physical. The linguistic level refers to levels of decomposition of a task. Examples of linguistic levels are given in table 2.
N°Linguistic level Example
7Goal visit a shelf in a real store
6Pragmatic visiting a product category page
5Semantic lect a combo box that links to the desired the product category page
4Syntactic display the list, lect the item
3Lexical items in the combo box, label “Select a category”, a button
2alphabetic a colour, the shape of an object
bec中级报名时间1physical moving the mou
gotye
Table 2. Linguistic levels of a guideline.
The complete list of ergonomic criteria adopted for this template is bad on the report of Bastien & Scapin (1993). Additionally an elementary criterion – adaptability - was added to adaptability criteria group. Also, the last criteria –compatibility – was expanded in three elementary criteria: task compatibility, ur compatibility, environment compatibility. Root ergonomic criteria are: guidance, workload, explicit control, adaptability, error management, consistency, significance of codes, and compatibility. Only elementary criteria should be ud. There are 21 elementary criteria in this t. For example, Significance of codes concerns the relationship between a term and /or a sign and its reference. Codes and names are significant to the urs when there is a strong mantic relationship between the codes and the items or actions they refer to.
The rationale consists of one-two phras justifying the guideline. For example, Guideline: U hypertext to structure the content space into a starting page that provides an overview and veral condary pages that each focus on a specific topic. Rationale: The goal is to allow urs to avoid wasting time on tho subtopics that don't concern them.
A negative example is a reference to a UI violating the guideline. A positive example is a reference to a UI respecting the guideline. For each example, we have:
·
a textual description that explains why or how the guideline was violated; if possible indicate the right solution;
· a picture that illustrates and documents the explanation;
·the reference where the example was found;
·original web address;
· a local directory / file name where the example is saved for a future u.
Both the original location and the saved page should be kept becau the original site could change in time thus leaving the web address and/or the example obsolete.
Guideline statement: Prerve previous attribute values as lected by the ur
Negative example: The Bluefly e-store does not prerve the size tting when choosing a product to examine it in more detail. Original address:
/list/catg.asp?zone=mens&sort=fresh&brand=&catg=ls&min=0&max=0&color=
&listview=b rand&sid=V0U9VC68P1S92LTA00A3HJBDN59B2EBA&mapsz=Mafw
Local address:
mlfD:\Guidelines\Examples\bluefly\list\catg.asp
Positive example. Each image must have alternative text.
This invitation web page related to the linguistic choice has got alternative text One ore more cas when the guideline does not apply, with negative and positive examples.
A t of relationships established with other guidelines according to a link topology. It can be one or many of the following: related-to, is the inver of, inherits from, is inherited by, generalis, specialis, precedes, follows, updates, precis, is a, is comprid in, belongs to, includes, is included in, is a ur of, is the owner of, has property, is an example of, is provided by, us, is ud by, is a requirement for, is alternative to, is contrary with, is conflicting with, updates / is outdated by,…
southampton
The ur interface type for which the guideline is valid. It can be one or many of the following: Graphical Ur Interface, Character Ur Interfaces, web, virtual reality, tactile, audio,…
A t of phas to whom it might concern. It can be one or more of the following: requirements specification, design, implementation, evaluation, training, education.
The activity domains the interface are targeted to and which may benefit from the guideline. It can be one or more of the following: e-commerce, e-banking, e-documents, CAD,…
The ur’s tasks that benefit from the guideline. The tasks are meaningful in the activity domain. It can be can be more than one task for which the guideline applies. For an e-commerce web sites the task could be classified within following categories: ur support (i.e., knowing the site, understanding return policies, understanding shipping conditions, contacting, looking for help), product navigation (choosing a store, choosing a product category, choosing a brand or a designer, specifying a display, product examination, detailed product examination), product picking (add to wish list, examining the wish list, add to shopping cart, examining the shopping cart), and checking out (checking the order, specify payment details, tracking an order).
Under the keywords ction are classified other attribute values that might be relevant for the guideli
ne organisation.
5. Conclusion
In this paper, we introduced a template for structuring design guidelines for the UI of interactive computer-bad systems. This template is currently being ud to input design guidelines into knowledge bas of the MetroWeb project. This software is a Web-bad tool for working with guidelines: any ur may input a guideline, submit it for revision to developers or human factors expert, and validate it. Once guidelines are accepted in a knowledge ba, they can be accesd through the web.
For instance, a ur interested to know usability guidelines applicable to mobile devices, such as WML-compliant cellular phones, may access the guideline ba for mobiles devices. In this ba, the ur can lect any subt of guidelines and retrieve them from the ba to form his/her own working ba. Examples can then be added, along with annotations. Guidelines for which some possibility for automated or computer-aided evaluation are considered for an extension of this tool.
REFERENCES
Bastien, C.J.M. and Scapin, D. “Ergonomic Criteria for the Evaluation of Human Computer Interfaces”, Technical Report No.156, INRIA, Rocquencourt, 1993.
Nieln, J. “A virtual Protocol Model for Computer-Human Interaction”, International Journal of Man-Machine Studies, 1986, Vol. 24, No. 3, pp.301-312.
Vanderdonckt, J. “Development Milestones Towards a Tool for Working with Guidelines”, Interacting with Computers, 1999, Vol.12, No.2, pp.81-118.
