<?xml version="1.0" encoding="UTF-8"?><article xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0-subset Balisage-1.2"><title>Why writers don't use XML<footnote><para>Or, indeed, LaTeX. Or even stylesheets for Word or
	OpenOffice.</para></footnote></title><subtitle>The usability of editing software for structured
    documents</subtitle><info><confgroup><conftitle>Balisage: The Markup Conference 2009</conftitle><confdates>August 11 - 14, 2009</confdates></confgroup><abstract><para>XML, LaTeX, and other structured-document systems are used
	daily by those experienced in computing, and by technical
	authors in many fields. Outside these areas, however, there is
	a widespread lack of adoption, or resistance to these systems.
	This forms a barrier to the creation and use of reliable,
	persistent, unencumbered, and reusable documents, which in
	turn adds a hidden burden to the use of corporate,
	institutional, and personal information.</para><para>This paper reports on a study of the usability of editing
	software for structured documents. It extends the research
	outlined in earlier work [<xref linkend="fly06"/>], where it
	was found that there was no essential difference in markup
	operations between any of the editing software tested, and
	that any distinction was possibly more attributable to the
	interaction design of the interfaces.</para><para>The objective is to see if changes to the interface to
	make it user-centered rather than technology-centered could
	result in greater acceptability to authors and editors both
	inside and outside the IT and markup fields, and thereby lead
	to an improved adoption rate of structure-guided writing and
	editing software.</para><para>The earlier analyses of software and features sought by
	users were extended to cover more recent data, and a survey of
	existing users was conducted to determine how the interfaces
	were being used. The results are being applied to construct a
	model of the interface which can be tested for usability
	compared with existing systems.</para></abstract><author><personname><firstname>Peter</firstname><surname>Flynn</surname></personname><personblurb><para>Peter manages the academic advisory and electronic
	  publishing unit at University College Cork, Ireland, and
	  also runs text management consultancy, Silmaril. He was a
	  member of the W3C's XML Special Interest Group and a member
	  of the IETF's Working Group on HTML. He is maintainer of the
	  XML FAQ and author of <citation>The World-Wide Web
	    Handbook</citation> (ITCP, 1995) and
	  <citation>Understanding SGML and XML Tools</citation>
	  (Kluwer, 1998). He is completing a belated PhD in software
	  usability, and in his copious spare time he surfs, cooks,
	  and listens to early music.</para></personblurb><affiliation><jobtitle>Department of Applied Psychology</jobtitle><orgname>University College Cork</orgname></affiliation><email>peter.flynn@mars.ucc.ie</email><link xlink:type="simple" xlink:show="new" xlink:actuate="onRequest">http://silmaril.ie/blogs/peter</link></author><legalnotice><para>Copyright © 2006 University College Cork.</para></legalnotice><keywordset role="author"><keyword>documents</keyword><keyword>editing</keyword><keyword>interface</keyword><keyword>latex</keyword><keyword>software</keyword><keyword>structure</keyword><keyword>usability</keyword><keyword>xml</keyword></keywordset></info><note><title>Acknowledgments</title><para>This paper describes research being submitted as
      part of a PhD in the Department of Applied Psychology, UCC
      (Human Factors Research Group).</para></note><section><title>Background</title><para>Writers and editors have until recently used a wide range of
      editing software. In the Humanities, document-based
      collaboration is relatively uncommon [<xref linkend="lar06"/>],
      so authors were less constrained by compatibility issues;
      whereas within the IT and scientific communities, the range has
      been smaller, partly because of the need to use specialist
      notations, and partly because of the need to remain compatible
      with co-authors [<xref linkend="ang04"/>].  In the wider world
      of writing outside research and academic institutions the
      difference was wider, because writers do not typically form
      homogeneous categories. Not all such software was necessarily
      ideal for the purpose, and much of it has fallen by the wayside
      in the path of technological advance; particularly in the face
      of the predominance of a single operating system and a single
      wordprocessor.</para><para>The onus of interpretation, customization, and rendering of
      publishable material has customarily been the responsibility of
      the publisher or other intermediary, who expends large sums on
      specialist labor for this purpose. However, in some fields,
      publishers have been asking authors for camera-ready copy for
      over 20 years to minimize costs<!-- [<xref
      linkend="lom83"/>]-->, and the effort involved and the quality
      of these submitted documents has been a cause for complaint on
      both sides [<xref linkend="lue07"/>]. Businesses, database publishers,
      libraries, search-engine optimizers, and printers have similar
      concerns: the quality of the documents (in source or
      camera-ready form) is often insufficient for meaningful capture,
      re-use, or formatting [<xref linkend="wil95"/>]. The causes are
      many, and have been well-established for many years, but among
      them is a lack of suitable software and lack of author education
      [<xref linkend="den86"/>, <xref linkend="hec93"/>].</para><para>As we showed in [<xref linkend="fly06"/>], there is no lack
      of software as such, only a lack of
      <emphasis>suitable</emphasis> software — for some value of
      <quote>suitable</quote> described by the respondents. In that
      report, we discussed three principal findings:</para><orderedlist><listitem xml:id="software"><para>In a study of editing software, we found that all XML
	  editors are basically the same XML editor: the facilities
	  provided are virtually identical, and the differences are in
	  the interface to these facilities, such as the depth of menu
	  traversal and the naming of actions, rather than in the
	  facilities themselves. The same is nearly as true of editors
	  for LaTeX, but as the markup can be changed arbitrarily by
	  the author, the manipulations required of the editing
	  software are not mandated or implied by the system as they
	  are with XML. Some specific deficiencies were noted which 
	  inform the adaptations made in <xref linkend="model"/>.</para></listitem><listitem><para>A survey of expert practitioners in the field of
	  markup-directed authoring and editing (taken to obtain a
	  baseline of recognized problems), we found that the
	  principal criterion for the recommendation of software was
	  familiarity or acceptability to the user, rather than
	  applicability to the tasks, largely because of the
	  difficulties in [re-]training users to an interface seen as
	  less suitable for non-experts.</para></listitem><listitem xml:id="requests"><para>An analysis of requests to the principal discussion
	  forums on XML and LaTeX asking for recommendations,
	  suggestions, or advice on the selection of editing software
	  was used to estimate the requirements of users. The four
	  most frequently-cited criteria were Cost (free or Open
	  Source software), a <quote>WYSIWYG</quote> interface, Ease
	  of Use, and Simplicity — over and above any
	  structure-related or markup-related facilities.</para></listitem></orderedlist><para>The investigations into software and user requirements
      (items <xref linkend="software"/> and <xref linkend="requests"/>
      above) were updated to 2008, measuring more recent applications
      and requests, but this showed that the original findings still
      hold. An additional inquiry was then undertaken to resolve the
      software facilities and the user requirements with actual
      current practice (<xref linkend="stuff"/>) and to build a
      model of a user interface to test the findings (<xref linkend="model"/>).</para></section><section xml:id="stuff"><title>How authors and editors use their software</title><para>The survey of users was constructed to find out what
      software the authors and editors used and how they used it. The
      survey was piloted for a week in April 2006 and the revised
      version made available online between February and April 2008.
      It used the phpESP web survey package, and was publicized via
      the online forums to which it was addressed (the comp.text.tex,
      comp.text.xml, and comp.text.sgml Usenet newsgroups, and the
      XML-L, TeXhax, and LaTeX (Google) mailing lists).</para><para>There were 62 valid responses. All respondents were
      guaranteed anonymity. An estimate of the population (those who
      might have seen the announcements of the survey) is difficult to
      make: the membership of the mailing lists was approximately 700;
      but the readership of the Usenet newsgroups is not knowable, and
      may extend to many thousands. The responses therefore represent
      a small interested sample, and there will have been many readers
      whose interests in XML were in its use for data representation,
      not structured documents.</para><para>Several attempts were made to widen the scope and seek the
      interest of publishers and writers' organisations in
      participating, but all were unsuccessful. The survey does not
      therefore represent the interests of the generality of writers
      but concentrates on identifying how users of structured editing
      software use their interfaces. Further work would be required to
      extend the reach of this enquiry into other fields.</para><para>The questions asked the respondents to describe their way of
      performing a set of actions, which were obtained from the
      requirements expressed in the updated analysis of user requests.
      The available responses in each case were presented as a
      multiple-choice list which was constructed from the updated
      survey of editing software to represent the known
      <quote>affordances</quote> (ways of doing things which are more
      or less obvious to the user: [<xref linkend="gib79"/>]). An
      <quote>Other</quote> category was also provided, but rarely
      used.</para><figure xml:id="background"><title>User Survey: background variables</title><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-001.jpg" width="100%"/></imageobject><caption><para>Number of subjects by industry and occupation by years
	    of experience and multiple responses to operating
	    system</para></caption></mediaobject></figure><para>A preliminary set of background questions was included to
      see if the responses varied by experience (years), operating
      system, occupation, or document types most commonly used.
      Unfortunately there was insufficient variability among the
      background data for any such effects to be detected, possibly
      due to the nature of an unavoidably self-selected sample (<xref linkend="background"/>).</para><para>Most respondents worked principally
      with text documents (77%); other document classes were in the
      single digit percentages. XML and HTML accounted for 44% of
      usage of markup systems; LaTeX, Word, and OpenOffice were
      roughly equal at 13–14% each. Wiki experience was surprisingly
      high at 8% but all others (including SGML) were at 2% or below
      (see <xref linkend="markup"/>).</para><figure xml:id="markup"><title>User Survey: Markup types used</title><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-002.jpg" width="70%"/></imageobject><caption><para>Percentages of all multiple responses</para></caption></mediaobject></figure><para>The editors most respondents had experience of were oXygen (24%)
      followed by Word (13%), Emacs (11%), and vi (7%) [both used for
      both XML and LaTeX]. Other LaTeX editors accounted for another
      12%. The Arbortext editor rated 6% along with OpenOffice, but
      there was a long tail of other products.</para><section><title>Results</title><para>The questions used a multiple-choice answer format because
	respondents were expected to use (or have used) many different
	systems. This enabled the survey to reflect a much wider range
	of behavior than would otherwise have been the case. In the
	following list, percentages are therefore of all responses to
	the question, not of the number of individuals.</para><variablelist><varlistentry xml:id="create"><term>Creating a new document</term><listitem><para>The method of creating a new document was divided
	      approximately equally between creating an empty file
	      (31%), emptying an existing document (29%) and using the
	      New Document menu item (28%). Most of the remainder did
	      not find the menu system useful for creating new
	      documents as it was faster to do it by hand.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-003.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="meta"><term>Adding standard metadata</term><listitem><para>To add metadata, 34% of responses used markup
	      insertion menus; 28% used fill-in-the-blanks
	      customizations; and 14% typed the markup manually. Most
	      of the rest used preset values or the metadata was
	      determined elsewhere.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-004.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="sect"><term>Starting a new sectional division</term><listitem><para>Nearly two-thirds of new sections were started by
	      positioning the cursor manually and typing or otherwise
	      inserting the markup (63%). Style menus were used in 14%
	      of responses and splitting an existing section in 11%.
	      Only 5% of responses used a <quote>New section</quote>
	      menu item.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-005.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="style"><term>Styling a document</term><listitem><para>Nearly half the responses said styling was automated
	      via a stylesheet (47%). The use of a style menu and
	      manual styling were about equal at 15–16%, and for most
	      of the others it was done by a production team. Only 2%
	      of responses mentioned using manual methods like toolbar
	      buttons.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-006.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="edit"><term>Moving element content</term><listitem><para>Moving blocks of text around was overwhelmingly done
	      by cursor highlighting and cut-and-paste. Only 15% used
	      a structure window to select the material. However, 11%
	      said they had to reorganize the markup manually after a
	      move (to promote or demote sectioning).</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-007.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="nav"><term>Navigating in the document</term><listitem><para>To navigate around the document, 30% of responses
	      used scrolling and 30% used searching. Only 17% used a
	      structure window, but 13% used keyboard shortcuts rather
	      than mouse controls.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-008.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="struct"><term>Adding new elements</term><listitem><para>To add new block-level material (elements in element
	      content), 35% of responses mentioned manual insertion by
	      keyboard shortcuts or typing; 26% via toolbar buttons;
	      and 21% via the Insert menu. Style-driven addition was
	      listed by 7% and there was another 7% of
	      <quote>Other</quote> which were
	      application-specific.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-009.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry><term>Linking and cross-referencing</term><listitem xml:id="link"><para>For linking items (cross-references, footnotes,
	      citations, and hyperlinks; which are largely
	      mixed-content insertions), 35% again specified keyboard
	      shortcuts or typing, and 23% via toolbar buttons. 21%
	      mentioned having to create the ID target before they
	      could add an IDREF link to it, but 16% used a
	      menu-and-dialog mechanism.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-010.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry><term>Viewing the formatted result</term><listitem xml:id="view"><para>Fully 40% of responses did not preview a document in
	      development, and relied on the structuring of the markup
	      to ensure it would be formatted correctly. 14% felt that
	      the synchronous typographic display was adequate as a
	      check, another 14% used toolbar button to show a typeset
	      preview window, and yet another 14% used a browser
	      preview. 11% ran a continuous synchronous previewer and
	      7% relied on a separate production team.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-011.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry><term>General approach to markup</term><listitem xml:id="method"><para>On the general question of the respondents' approach
	      to editing, roughly equal numbers (37–38%) were
	      comfortable with a system that allowed them to specify
	      markup without prescription, and with systems than
	      encouraged but did not enforce a specific way of marking
	      up (for example, optional structural-based styling in
	      wordprocessors). However, 20% did prefer a prescriptive
	      system.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-012.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry></variablelist><para>Respondents were also asked in open-ended questions about
	what features they would recommend to others looking for
	software; what features they found best and worst in their
	software; and for any features they would like to see
	added.</para><!--<variablelist spacing="compact">--><variablelist><varlistentry xml:id="sel"><term>Advice to others</term><listitem><para>The most important feature was seen as robust
	      compliance with standards (15%). 7% recommended
	      customizability, and 6% felt integration with other
	      systems was important. Level at 4% were <quote>Avoid
		WYSIWYG</quote>, <quote>Avoid Wordprocessors</quote>,
	      and <quote>Keep it simple</quote> (the converse,
	      <quote>Use WYSIWYG</quote> rated 3%). Again there was a
	      very long tail of other factors, but without significant
	      distinction.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-013.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="useful"><term>Most useful features</term><listitem><para>For usefulness, keyboard shortcuts rated the highest
	      at 14% of mentions. Regular Expression searches followed
	      at 11%, and Integration and Validation features at 8%
	      each. A cluster of editorial functions came next at 5–6%
	      each: context-sensitive or structure-sensitive editing;
	      spell-checking, grammar-checking, and thesaurus;
	      autocompletion; and WYSIWG display. At a lower level
	      (3%) were colored editing, adaptability and
	      customizability, and the quality of formatting,
	      DTD/Schema handling, and cross-referencing. Price and
	      multi-platform availability were not significant at
	      2%.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-014.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="useless"><term>Worst features</term><listitem><para>By contrast, the worst features of editors were led
	      by automated or pre-emptive insertion problems at 20% —
	      wrong types, interference with formatting, refusal to
	      mark up as instructed, or insistence on adding incorrect
	      markup. Validation errors (faulty editors, not faulty
	      documents) followed at 11%, and WYSIWYG problems at 9%.
	      Quirkiness or obtuseness of the interface were rated at
	      7% and 5% respectively (failure to follow established
	      patterns), and matters related to styling and formatting
	      also at 5%. Poor documentation, the need for manual
	      intervention, lack of Unicode support, program
	      stability, and support for different file formats all
	      rated 4%, and there were others in a low long
	      tail.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-015.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="failed"><term>Failure to fulfil a task</term><listitem><para>When asked if they had ever failed to find out how
	      to do something that an editor was actually capable of,
	      35% mentioned the difficulty of finding items in
	      documentation, and 26% mentioned problems in getting an
	      editor's special feature (one of its unique selling
	      points) to work. 13% mentioned trying to overcome
	      unnecessary complexity, and 6% felt that such failure
	      was down to lack of awareness of a product's
	      capabilities. The tail included mathematical features,
	      searching, validation, and WYSIWYG problems.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-016.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry><varlistentry xml:id="wish"><term>Wish list</term><listitem><para>The opportunity to add to a Wish list led the
	      <quote>Other</quote> category to account for 27% of
	      responses. Heading the remainder were improved
	      documentation (20%), better WYSIWYG (17%), and better
	      interfaces (13%) and menu systems (10%). The addition of
	      Regular Expressions rated 7% and better access to
	      styling also 7%.</para><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-017.jpg" width="90%"/></imageobject></mediaobject></listitem></varlistentry></variablelist></section><section><title>Discussion</title><para>In the open-ended questions, and in the
	<quote>Other</quote> areas of each question, users were able
	to elaborate on their responses. In these, there was sometimes
	extensive and persuasive argument both for and against the
	exposure of markup, the limitation of structural control, the
	adaptability of editing systems (including DTDs and Schemas),
	and the conflict between how a writer perceives interaction
	with a document and how the creator of the editing system
	perceives it. These views — necessarily one-sided, as they
	come from long-term authors with technical understanding,
	rather than from non-technical writers or newcomers (see
	<xref linkend="background"/>) — illustrate an important point
	about <quote>structure</quote> which has not been widely
	considered at a technical level.</para><para>While it is accepted wisdom that <quote>structure</quote>
	is A Good Thing in all writing (and this has become an article of
	faith in markup theory), there is a difference between what
	markup experts mean by structure and what writers understand
	by it. Both parties accept that there is a framework
	underlying all formal documents, usually in the conventional
	part-chapter-section-subsection hierarchy, with other
	components adduced where needed (principally figures, tables,
	lists, and their derivatives). The differences appear to lie
	in the perception of the relationship of these elements to
	each other.</para><para>The classical theory, derived from computer science and
	graph theory, is that the document is a hierarchical tree
	(actually inverted: a root-system) and that all necessary
	actions can be seen in terms of navigation around the tree,
	and of insertion into and withdrawal from the the nodes which
	form the branches and leaves.</para><para>The conventional writer, however — and we expressly
	<emphasis>exclude</emphasis> the markup expert, as well as the
	experienced technical authors who responded to the survey — is
	by repute probably only marginally aware of this tree; but we
	have been unable to measure this at present. In this view, the
	document is seen as a continuous linear narrative, broken into
	successive divisions along semantic lines, and interspersed
	with explanatory material in the form of figures, tables,
	lists, and their derivatives. From inspection, this appears to
	hold true whether it is a sales report, a novel, a textbook,
	or an academic paper. The terminology used is therefore also
	different: <quote>inserting</quote> a <quote>node</quote> into
	the tree has meaning for the document engineer who designs the
	document type or the formatting engine, but is meaningless for
	the writer, who thinks in terms of <quote>new chapter</quote>
	or <quote>add a paragraph</quote>.<footnote><para>In the case of narrative or dramatic literature,
	    <quote>structure</quote> has entirely other meanings, and
	    concerns plot revelation, narrative pace, character
	    development, and other factors completely unrelated to our
	    use of the term.</para></footnote></para><para>This may explain to a considerable extent why the
	<quote>anything, anywhere</quote> document model in
	commonly-used wordprocessors has become so pervasive: it is
	virtually impossible expressly to allow an object to occur
	only in a specific place, or to forbid one from occurring at
	any point. The interface to such models has become widespread
	precisely because it allows this latitude, regardless of
	whether it makes structural sense or not, and because such
	interfaces are marketed for general-purpose, ad hoc, and
	trivial use, as well as for complex or sophisticated use. This
	is despite the result that in terms of formal structure, all
	wordprocessor documents are in effect a simple series of
	paragraphs one level deep (with a small exception for those
	that group list items in a container or provide containment at
	the mixed-content level).<footnote><para>Containment has its own perils: the author has an
	    example of an OpenOffice document, a book of a dozen
	    chapters by different authors, in which the editor
	    unwittingly pasted chapters two to twelve into the bounds
	    of the last endnote at the end of the first chapter. The
	    publisher asked for some endnotes to be subsumed into the
	    text, and when the editor deleted the last endnote of the
	    first chapter, all the remaining chapters vanished from
	    the document.</para></footnote></para><para>It would therefore appear that the lack of adoption of
	structured-editing interfaces could be due to a lack of
	understanding by authors of the tree model, or to a sense that
	it constrains them unreasonably during the writing process.
	But the existence of the tree, and its supervention in the
	interface, are artefacts of the way in which editing software
	has been written, and reflections of the preoccupations of the
	designers and programmers. This is made plain by the fact that
	the interface of structured editors implements the tree,
	rather than implementing a model of the document with which
	the author is more familiar. The use of the synchronous
	typographic interface (popularly, if erroneously, known as
	<quote>WYSIWYG</quote>) goes some way towards hiding the
	technicalities of tree-based editing, but our objective here
	is to investigate the extent to which it is possible to
	present writers with a model of the document which matches
	<emphasis>their</emphasis> expectations rather than those of
	the document engineer or programmer.</para><para>Taking this view, it is possible that an interface which
	provides the existing markup facilities (from a document
	engineering point of view) but replaces the
	engineering-oriented or technology-oriented approach with one
	more closely matched to the users' expectations, would stand a
	better chance of acceptance among authors. While this has been
	attempted in some recent products, it appears to have
	addressed specific individual demands rather than the general
	principle.</para></section></section><section xml:id="model"><title>The interface is the product</title><para>The development of the graphical user interface, common
      support libraries, dynamic data exchange, object linking and
      embedding, context-awareness, and many other related
      technologies, has led to the frequent blurring of the
      distinction between applications for the user. Sending an email
      can now invoke the default wordprocessor as the editor; clicking
      on a hypertext link in a document will open a web browser;
      following a link in a browser will open the (usually)
      appropriate application for the type of file; and a table in a
      document could be provided by an embedded spreadsheet object.</para><para>The commonality of the interface framework (the position of
      the menus, arrangement of the toolbar, and availability of the
      other affordances) increases software reusability and makes it
      easier for the user to carry across skills from one application
      to another; but it also leads users into a state of unawareness
      of exactly which application is active at any one time. This
      also provides one of the building-blocks for the development of
      interface components which are generically grouped under the
      banner of <quote>Web 2.0</quote>, which attempts to imbue all
      visible objects with the status of an affordance.</para><para>A side-effect of this is that a large number of
      applications, even across platforms, share an increasingly
      common interface framework, and are increasingly expected by the
      users to provide the same affordances. User tolerance for
      differences based on platform, vendor, or application appears to
      be shrinking, such that a new product would have to offer some
      very radically new and valuable feature indeed for it to justify
      breaking the conceptual mold expected by the user.</para><para>Taking into account the expectations of users found in the
      survey above, there is a growing sense that the interface is the
      product, and the product is the interface, regardless of the
      technologies employed underneath. The structure-directed
      document editing model, which requires a foreknowledge or
      awareness of the underlying hierarchical document model, may
      prove to be unsatisfactory in the light of this approach.</para><para>Building on the information gathered in the surveys it was
      possible to construct a list of operations or actions
      (keystrokes, menu items, toolbar buttons) which were seen as
      problematic. This meant either that they were to be handled
      specially or even avoided because of their meaning or ambiguity
      (in the opinion of the expert practitioners); or that they were
      opaque to the user because of terminology, placement,
      expectation, or effect (in the opinion of the users).</para><para>From the requirements of users in the survey of requests to
      the forums, editing software is required by most users to
      <quote>be WYSIWYG</quote>; that is, to employ a synchronous
      typographic interface with no markup visible to the user.
      Whether or not an editor allows another form of access to the
      markup (tokenized, raw text, breadcrumb, or marching display),
      is not relevant for the present purpose: this is something the
      software creator can choose to do or not to do.</para><para>In all cases it was seen as a priority that the behavior of
      the interface should be <quote>what the user expects</quote>.
      Where in some cases this becomes context-dependent, it was
      regarded as essential that the behavior should
      <emphasis>not</emphasis> be the simple binary-strict IR or CS
      refusal on the grounds that <quote>you can't do that
	here</quote>. This was cited on numerous occasions both in the
      surveys and in related discussions as being The Wrong Thing,
      especially when the user's action was seen as perfectly
      reasonable, but simply happened to take place at a time when the
      cursor position indicated otherwise.</para><para>In all cases discussed, it was seen as important to avoid
      asking the user a question in order to determine what is The
      Right Thing unless absolutely essential. Additional interface
      features which learn from past behavior, and which allow
      preferences to be set where there might be ambiguity, were
      considered to be outside the scope of this model. While these
      have been implemented in some systems, the present author is
      unaware of any specifically related to structural editing, and
      this would be an important area for future work.</para><para>It cannot be emphasized too strongly that users, and
      especially intending users, vote with their feet when judging an
      application by its interface. In the absence of compelling
      direction from elsewhere in an organization, and where products
      are essentially comparable in function, an interface's
      appearance as well as its apparent usability are regarded as
      actually <emphasis>being</emphasis> the product.</para><para>By contrast, when functions are widely disparate, and the
      interfaces are roughly comparable, the functions may become the
      product. As we saw earlier, some interfaces fail to afford
      features that do actually exist in the product, and this may
      provide a third effect on the perceived usability.</para><para>In all three cases the quality, behavior, performance, and
      other attributes of the underlying engines and routines may only
      rarely be considered by the individual user except as part of a
      formal evaluation process, and may even then be dismissed in
      favor of the specific attractions of a particular interface. The
      importance of accurate interface usability testing
      <emphasis>before product release</emphasis> cannot therefore be
      ignored: while the market will always have the final say,
      releasing an untested interface is likely to be
      counterproductive.</para><para>The following changes to the interaction are derived from
      the findings of the four enquiries (experts' survey, software
      analysis, user requirements study, and user survey), and will be
      subject to testing in the final phase (see <xref linkend="testing"/>).</para><section><title>Keypresses</title><section><title>The Enter (Return) key</title><para>In most synchronous typographic wordprocessor
	  environments the default action is to end the current
	  paragraph and start a new one (the older conflation of
	  <quote>new line</quote> and <quote>new paragraph</quote> has
	  mostly disappeared from wordprocessors but it still present
	  in the less capable web editors). In the case of list items,
	  Enter starts a new item rather than a new paragraph within
	  the same item.</para><para>The behavior in an environment like a list raises the
	  question of how to exit the list environment — how to revert
	  from list-item creation to normal paragraphs — when the
	  markup is invisible. This is critically relevant where the
	  system is unable to allow the placement of the cursor beyond
	  the end of the last environment because no markup is
	  visible.</para><para>The <quote>next-paragraph</quote> behavior can usually
	  be modified in a stylesheet, so that a given paragraph style
	  (for example, Title) can be programmed to create a new
	  paragraph of another style (eg Author) when Enter is
	  pressed. In tabular matter, it may navigate down a cell, or
	  create a new empty row. In some SGML/XML editors
	  investigated, however, it caused a system beep or the
	  insertion of white-space in mixed content.</para><para>Because of its history, there is an expected
	  <quote>down</quote> (linefeed) action associated with the
	  key, and the first two examples above conform to this (new
	  paragraph; new item), as does the stylesheet-directed
	  creation of a specific following style, and this is the
	  defined behavior.</para><para>The problem of terminating a list or similar
	  second-level container was partly solved in Emacs
	  psgml-mode, STiLO, and some other editors by detecting a
	  repeated Enter or split-element instruction (C-c RET in
	  Emacs) with no intervening keystroke, and interpreting this
	  as signaling a demand to exit to the next level up in the
	  hierarchy. In STiLO, a third and subsequent presses cycled
	  through all element types available at that level. While
	  this kind of complex behavior is very useful to the expert,
	  it is not easily guessable, and is not obvious to the
	  non-expert. Ctrl-Enter was adopted for this <quote>exit
	    container</quote> action on the grounds that it is already
	  familiar in the sense of a <quote>hard return</quote>, and
	  with the possibility that this should be configurable by the
	  user, perhaps via a beginner/expert mode. There appears to
	  be no suitable alternative paradigm from online editing
	  (wikis, blogs, IM) which could be adopted.</para></section><section><title>The TAB key</title><para>Informally, many experts would concur in banning this
	  key altogether by disabling it. Its typewriter-style use to
	  align text with locally-dependent locations across the
	  user's window is a good example of a visual-only
	  instantiation which is not stable.</para><para>In practice it appears to have two valid uses, given its
	  association with the <quote>forward</quote> direction,
	  especially in tabular matter.</para><para>One use is to navigate forward linearly through markup;
	  that is, from one element or text node to the next in mixed
	  content, identifying its location in a telltale or highlight
	  (this might solve the problem of cursor placement beyond the
	  last text node referred to above); and from one element to
	  the the next in serial order in element content, in effect
	  performing a width-first traverse.</para><para>The other use is as an <quote>Insert Table</quote> key
	  when outside a table, moving to the next available location
	  where a table make sense; and it would revert to the
	  traditional spreadsheet-style cell-to-cell traverse when
	  inside a table. Both uses were designed to be tested.</para></section><section><title>The spacebar</title><para>Apart from inserting spaces in character data content,
	  there appears to be no other legitimate use for the key in a
	  structured editing environment. Its use as a pager key in
	  Unix-based systems and its adoption by web browsers for a
	  similar purpose, as well as its use as a button or link
	  selector, is be avoided in the current context except for
	  accessibility functions when using the menus and
	  toolbars.</para></section><section><title>Backspace and Delete</title><para>Backward and forward deletion in character data content
	  would operate as expected. When adjacent to a markup
	  boundary, however, it seems reasonable that deletion should
	  continue in the same direction by jumping linearly to the
	  next point where character data exists (if any; attribute
	  values excluded), possibly accompanied by a transient audio
	  or visual warning.</para><para>Another possibility is that when all character data
	  content has been deleted from an element, and all descendant
	  elements are similarly empty, an additional press of one or
	  other of these keys should remove the containing element
	  itself. This would conform to the expectation of deletion
	  associated with both keys, but requires separate testing as
	  it may or may not conform to the user's expectations when
	  content has already been deleted, as the user will be
	  unaware of the existence of any empty markup structure when
	  there is no character data present.</para></section></section><section><title>Menu items</title><section><title>The NEW menu item</title><para>Many writers on interface usability deprecate the use of
	  nouns and adjectives on toolbar and menu labels, and insist
	  that using verbs or attributes allows greater comprehension
	  (the canonical example being [<xref linkend="app08"/>]). In many cases they are right, but
	  in the case of software for writing, the terms commonly used
	  (in English) include phrases such as <quote>new
	    chapter</quote>, <quote>new paragraph</quote>, or
	  <quote>new section</quote>, and these are so prevalent a way
	  of expressing the action that they justify being collected
	  under a menu or toolbar button labelled
	  <quote>New</quote>.</para><para>The first encounter with this is already familiar in
	  many editors as <quote>New Document</quote>, which allows
	  selection from a set of precompiled DTDs or Schemas. The
	  user indications in the survey were that such a set needs to
	  be very much wider, and must allow a much easier method of
	  adding new document types. (Although that activity is
	  outside the scope of this study, it does have implications
	  for document type and stylesheet designers and for the
	  introduction of a robust means of element type and attribute
	  <quote>hint</quote> documentation.)</para><para>The use of <quote>Insert</quote> (which we discussed
	  earlier), or <quote>Surround</quote>/<quote>Enclose</quote>,
	  are always restricted to the element types available at the
	  current cursor location (which may be indeterminable by the
	  user when no markup is visible). By contrast, a selection
	  from a <quote>New</quote> menu moves to the next available
	  location where the selected item can be inserted, if the
	  current location precludes it. If the user asks for a new
	  chapter, and their cursor is currently in the middle of an
	  acronym, they do not mean literally insert the new chapter
	  markup there, or recursively split elements until a valid
	  insertion point is reached; they mean go to the next place
	  where a chapter can start, and start it there.</para><para>When requesting the insertion of inline markup in mixed
	  content, however, <quote>Add</quote> may be convenient
	  semantic sugar for <quote>New</quote> (as in <quote>add
	    quote</quote>, <quote>add emphasis</quote>). The same
	  principle of <quote>next available location</quote> would be
	  honored, as such markup can usually occur arbitrarily in
	  mixed content.</para><para>As a corollary to this principle, where a new element
	  has required element content, <emphasis>all</emphasis>
	  required element types must be added, and the focus then
	  returned to the first location of character data. Where
	  there is a required choice, that must be presented to the
	  user (one of the unavoidable occasions, and perhaps a
	  suitable opportunity for the implementation of the first
	  mode of TAB key operation explained above).</para></section><section><title>Formatting controls</title><para>Given that a synchronous typographical editor operating
	  with a stylesheet would not normally have any use for the B,
	  I, and U buttons, nor for the typeface and font-size
	  dropdowns, it is tempting to abolish them completely except
	  when in style-creation mode.</para><para>However, as the user expects to be able to control
	  formatting from the menu and toolbars, the B, I, and U
	  buttons should operate a drop-down of all the available
	  markup which uses those styles in the current stylesheet.
	  For example, as we have pointed out elsewhere, there are at
	  least eight reasons<footnote><para>To which might validly be added
	      <quote>illustrative</quote> for authors of manuals on
	      typography.</para></footnote> why an author or editor might want to
	  use italics,
	  <!--<itemizedlist spacing="compact"> -->
    <itemizedlist><listitem><para>foreign words</para></listitem><listitem><para>scientific names</para></listitem><listitem><para>emphasis</para></listitem><listitem><para>titles of documents</para></listitem><listitem><para>names of products</para></listitem><listitem><para>mathematical variables</para></listitem><listitem><para>headings</para></listitem><listitem><para>decoration</para></listitem></itemizedlist> and probably as many again for bold and
	  underlining combined [<xref linkend="fly02"/>].</para><para>By the same token, the typeface dropdown (restricted to
	  those faces in use by the stylesheet) can be used to select
	  from those elements currently employing those faces; and the
	  font-size dropdown to select those employing those sizes.
	  The effect for the user is identical to the existing usage,
	  and requires no additional mouse-click, only a longer dwell
	  time and a move to select the right usage.</para><para>A similar argument can be made in favor of other visual
	  selectors such as color. In stylesheet-editing mode, if one
	  is provided, the buttons and dropdowns may revert to
	  conventional usage to allow new styles to be constructed or
	  existing ones to be modified.</para></section><section><title>The toolbar</title><para>Many remaining items on a conventional toolbar can to a
	  large extent be replaced by markup-oriented controls when
	  working with a stylesheet, using the principles given
	  above.</para><para>Toolbar items with an application in markup control,
	  such as those for use with tabular setting, can of course be
	  retained largely unchanged, but by the same token they must
	  disappear from the toolbar when the DTD or Schema has no
	  tabular elements: a corollary of providing the user with the
	  best affordances possible is that inapplicable ones should
	  be eliminated.</para><para>The non-markup document controls such as Save, Open, and
	  Print are of course retained in their normal form.</para><para>Additional buttons for cross-reference management,
	  citation, indexing, and other apparatus common in structured
	  formal documents are added where the DTD or Schema provides
	  for such facilities. These are already familiar to many
	  users from reference management software.</para><para>Generic tools such as spellcheckers, thesauruses, and
	  grammar-checkers remain unaffected, but they need to be
	  relevant and up-to-date: a number of applications tested
	  failed to include common technical terms like
	  <quote>filetype</quote> as well as recent everyday words
	  like <quote>blog</quote> and <quote>wiki</quote>.</para></section></section><section><title>Other</title><section><title>Referencing</title><para>For normal cross-references (assuming the ID/IDREF
	  mechanism is used), adding a reference to an existing target
	  is non-problematic, requiring only a pop-up of available
	  targets, or acceptance of a scroll to the target and a click
	  on it). An attempt to add a reference to a non-existent
	  target must create a placeholder for the point of reference,
	  and then require the user to identify the target, completing
	  the resolution when the target is established. In both
	  cases, the stylesheet must know the correct generated text
	  to add at the point of reference, if any, either based on
	  the element type of the target (table number, section
	  number), or as a page number. In all cases, moving the
	  target ID to another element will update all references to
	  it.</para><para>For bibliographic references, the stylesheet must
	  contain sufficient information for the correct formatting
	  style (or choice) according to the conventions of the
	  discipline. A similar behavior to the normal cross-reference
	  action can be assumed when the reference entries are
	  embedded in the document (as is possible with DocBook or
	  LaTeX, for example), but this can be pre-empted by dragging
	  and dropping a reference from an external citation database,
	  either maintained locally like Zotero, Endnote, or BIBTeX,
	  or from suitable data in a browser page on a journal or
	  reference database site; with the ID resolution being
	  satisfied by the inclusion of the referenced item in a
	  suitable format at the end of the document.</para></section><section><title>Mathematics</title><para>The visual control of mathematics poses special problems
	  which have been addressed in several models developed by
	  software writers and vendors (Euromath, Arbortext, LyX,
	  Scientific Word, and others), and is not considered
	  here.</para></section><section><title>Unstructured editing</title><para>Several respondents to the surveys mentioned the need
	  for systems which deduce structure while the author writes
	  without structural controls; for systems which can open
	  documents with broken structure (that is, badly-formed or
	  invalid documents) in order to allow them to be mended; and
	  for systems which allow incomplete but otherwise well-formed
	  or valid documents to be saved for later completion. While
	  these are unquestionably still needed [<xref linkend="bir97"/>], and mechanisms for their instantiation
	  have been available for many years [<xref linkend="sha95"/>], they are outside
	  the scope of this research.</para></section><section><title>External files</title><para>The use of drag-and-drop is an essential interface
	  component for the inclusion of images, real-time updates,
	  file objects, and other linking actions (like the
	  bibliographic citations mentioned earlier), although
	  traditional attribute entry of filenames and URIs must
	  remain accessible. The embedding of local (file:///) URIs is
	  deprecated for reasons of non-portability, but no viable
	  solution is apparent for standalone usage without widespread
	  adoption of a catalog method (below). The embedding of
	  non-standard methods such as links to OLE objects and local
	  email repositories is a particular difficulty.</para><para>A particular demand was seen for the management of
	  external entities, both parsed and unparsed, as this was
	  given as a deficiency in many editors. The use of XML
	  Catalogs is regrettably under-developed.</para></section><section><title>Character data</title><para>It ought to be unnecessary to mention explicitly, but
	  all visible (printable) keyboard characters — indeed all of
	  the Unicode repertoire — must be accepted without error.
	  With markup hidden, there can be no excuse for markup
	  characters entered from the keyboard being interpreted
	  <emphasis>as</emphasis> markup characters.</para><para>Where letters or symbols from outside the base character
	  repertoire of the document are entered, editors for systems
	  which require additional facilities to handle them (such as
	  LaTeX) must automatically add the relevant modules
	  (packages) to the Preamble (an approximate equivalent to the
	  Internal Subset of an XML document).</para></section><section><title>Editing</title><para>The cut/copy/paste actions applied to character data in
	  text nodes behave as normal. The three-button equivalent
	  mouse actions common in some systems must remain available.
	  Embedded whole-element markup in mixed content is
	  cut/copied/pasted with any marked surrounding character
	  data, but will silently disappear if pasted into a location
	  where that markup would be invalid (see the rules governing
	  Target Markup Adoption below).</para><para>The paradigm of clicking on the start-tag to mark the
	  whole of an element is inapplicable when markup is
	  invisible, and a tree or other diagrammatic representation
	  of the document in a side-pane may be confusing for the
	  non-expert, but an equivalent style-oriented margin similar
	  to Word's allows whole-element selection in element content,
	  as does the three-click selection in Mac OS X.</para><para>Cutting (or copying) whole elements in element content
	  and pasting them elsewhere is subject to the rules of the
	  DTD/Schema in use. If the user attempts to paste the
	  material into a location where the markup would not be
	  permitted (into mixed content, for example), the markup in
	  the clipboard content is removed down to the mixed content
	  level, and the result pasted as mixed content. Pasting
	  whole-element material from element content into element
	  content at a higher or lower level automatically promotes or
	  demotes the container of the clipboard content to a suitable
	  level to be allowed.</para><para>Highlighting across markup boundaries copies the marked
	  character data and any embedded whole-element markup. As
	  mentioned above, cut/copy and paste then work on the text
	  nodes in mixed content and any whole element nodes included
	  in the selection. A principle which we term <quote>Target
	    Markup Adoption</quote> determines that pasting
	  fragmentary mixed content adopts the style of the target
	  container and <emphasis>not</emphasis> the source style,
	  whereas pasting whole elements (in element content) retains
	  the internal consistency of styling, subject to any
	  inheritance or disinheritance at the target location. This
	  principle is already in partial use in some embedded XML
	  editors designed for web applications.</para><para>An attempt to apply (inline) styling to marked text
	  across element boundaries will surround any text with the
	  appropriate markup where permitted, but leave text unmarked
	  in elements where the relevant subelements cannot be
	  applied.</para></section></section><section xml:id="testing"><title>Testing</title><para>Implementing this in program code would, in effect, mean
	rewriting a large part of the interface of an existing editor,
	or writing an entire new one from scratch. As this is beyond
	the scope of the research, the Paper Prototyping method of
	testing is being used [<xref linkend="sny03"/>].</para><para>This involves preparing sequences of screenshots or
	facsimiles on sheets of paper, and giving test subjects tasks
	which they carry out by indicating on the sheets what action
	they would take. The tester then replaces the sheet with the
	one which shows the result of that action, and the process is
	repeated. A record of the sequences is kept for analysis. The
	use of Personas (constructed psychological profiles of
	canonical users) enables experienced test subjects to match
	responses to those of the target audience. Testing will be
	carried out in the Usability Laboratory of the Human Factors
	Research Group at University College Cork.</para><para>The actions and behaviors are specified as sequences of
	keystrokes or mouse movements, and prepared for testing using
	generated simulations of screenshots (see <xref linkend="testscreen"/>.</para><figure xml:id="testscreen"><title>Paper prototyping: simulated screenshot of model
	  editor</title><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-018.jpg" width="100%"/></imageobject><caption><para>Use of the <quote>New</quote> menu in mixed
	      content</para></caption></mediaobject></figure><para>Duplicates of each screen using the existing interfaces of
	OpenOffice, Word, or oXygen as appropriate will be used for a
	control sample (see<xref linkend="controlscreen"/>.</para><figure xml:id="controlscreen"><title>Paper prototyping: control screenshot using
	  OpenOffice</title><mediaobject><imageobject><imagedata format="jpg" fileref="../../../vol3/graphics/Flynn01/Flynn01-019.jpg" width="100%"/></imageobject><caption><para>Inserting a paragraph break</para></caption></mediaobject></figure><para>Testing will be conducted in the autumn of 2009.</para></section></section><bibliography><title>References</title><bibliomixed xml:id="ang04" xreflabel="Anghelache2004">Angelache,
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