The choice o f shared workspace tool was subject to a number o f constraints. Neither o f the tools used had all the features which research had already shown to be desirable. It was therefore likely (and so it proved) that this would result in re-finding out requirements that had already been established. However, the tools had several advantages. Both were robust and reliable. Between them, they allowed all the required areas to be investigated, as Table 6.2 shows. It was also possible to affect the development o f
nte, the shared text editor.
Table 6.5 summarises the differences between the two tools. Perhaps more importantly, it shows that, between them, they offered most o f the features which previous research had shown to be desirable in a shared workspace tool (see Chapter Three, section 3.3).
FEATURE/FUNCTION Wb Nte SP A C E & NAVIGATION
Multiple pages. Slider and arrows.
Scrollable canvas
Document map, showing location o f activity
O BJEC TS & OPERATIONS
Text Type: keyboard entry Yes Yes
Import: file entry Yes Yes. Size limit. Truncates files above this. Always inserts at top o f page. Imported file becomes a block o f text.
Fonts Four fonts, including one italic; 3 sizes for each
Courier, one size, plain, italic, bold, bold-italic.
Text editing Can add and delete characters while typing current text object. After it is created, can only delete or move it.
Can add or delete characters at any time. Can also move, delete, change colour.
Operations on whole text block only. Can not select and edit words or paragraphs which are part o f the block.
G raphics Draw Freehand plus some graphics primitives (line, ellipse, rectangle), arrow.
No
Import image file Yes No
Formats for image files
Postscript N/a
Colours 8 including black and white. Lighter colours can be difficult to see on white background
8 including black. All show up resonably well on white background.
Graphics editing No - only move or delete N/A
FLOOR CONTROL
No system controls No system controls
REFERENCE
Shared pointer No Yes - user invokes with right mouse button
SHARED VIEW S/W YSIW IS
Page changing, scrolling
De&ult: page automatically changes for all to the one where activity is taking place, enforcing shared view. Individual can override this by locking her/his page.
Individuals can scroll to different parts o f the document. No shared view enforced.
Resizing windows Individuals can resize window independently; redrawn page preserves view by scaling page contents.
Individuals can resize window, or alter inter&ce. This may cause text to be hidden.
OTHER CONTROLS
Ownership o f objects Only creator can modify object D efiiult- all participants can modify all objects. Lock mechanism can override this.
ACTIVITY FEEDBACK
Participant information visible
Activity window shows participant names and highlights active user(s). Also shows multicast address/port and encryption key.
Can choose to display participant names. These are highlighted when active. Pointer, pen and truck icons carry participant name and current colour.
Visible cursor No Yes (in the form o f a pen and truck icon.)
OTHER
Can print whiteboard contents. Mute input from new sources. Select either point o f click to type.
Encryption.
Save workspace contents Encryption
6.6.1 Shared whiteboard - Wb
The shared whiteboard, W b (Figure 6.5 ), was developed to provide a shared display for multimedia conferencing amongst researchers in the field o f networked multimedia. Projects such as MICE (Sasse & Bennett, 1995) helped to broaden the user base, but there is no Windows or Macintosh version, which has limited its adoption. Versions are available for UNIX platforms (including Sun, Dec Alpha, SGI) and for PCs running Linux and Free BSD.
F ig u re 6.5: - w b w in d o w
A toolbar on the right, vertical edge o f the drawing area offers a selection o f tools: freehand drawing, straight line, arrow, rectangle, ellipse, erasing, moving and copying objects, choosing font (a limited choice), colour and brush size. On this bar there are also: Undo, Print and Quit buttons and buttons to alter the orientation o f the page.
Buttons on the bar along the lower, horizontal edge allow the user to create new pages, navigate through the pages and import files. Only ASCII or Postscript files are accepted. Input is also via keyboard and mouse. All participants may write, draw and type in the working area simultaneously; there is no built-in floor control mechanism.
The working area is divided into pages. Any user can create a new blank page. A slider is used to move between pages. The current page number is displayed, with the name o f its creator. The default behaviour o f w b is to enforce a page change on all participants if one participant changes page. It is, however, possible for an individual to override this and “lock” a page s/he is working on.
Limited resizing o f the window is allowed. Such resizing is not enforced on other participants but objects on the page will be redrawn and scaled to ensure that the user retains the same view o f whatever is displayed, proportionally resized.
Although all participants in the session can use w b simultaneously, it is not possible to carry out an operation on an object created by someone else. There are no visible cursors and there is no shared pointer. Once an object is created, it can not be edited, only moved or deleted.
6.6.2 Shared Text Editor - Nte
N te (Figure 6 .6 ) is a shared text editor, hence the absence o f graphical display features. Like w b it was designed for research into multimedia conferencing, in this case to allow remotely located users to keep notes during a meeting or to share text documents. At the time o f the trial, versions were available for UNIX (Sun, SGI, HP) and PC (Linux, NT, Windows95).
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Figure 6.6: nte window, showing pen icon, pointer, participant list, docum ent map
Text can be entered via the keyboard or from a file. The unit on which nte operates is the block o f text. A block may be o f any size, from a single character to the file size limit that the user selects. After being defined, a block can be edited, moved or deleted. The style and colour o f font can also be changed. A block can not, however, be restructured; existing blocks can not be subdivided or combined, for example, and modifications such as colour changes work on the whole block. Unlike wb, nte allows text files to be saved.
The nte work space is a single canvas and navigation is by scrolling. Users can choose to display a list of participants and a map o f the canvas to help them locate activity. The nte window may be resized by individual participants more flexibly than is the case with wb. If this is done the existing text is not re scaled and other users are not notified.
Unlike wb, there is a shared pointer. A pen icon (see Figure 6.6) appears when participants make contributions and a truck icon as they move objects. The pointer and icons can be labelled with participant name and appear in the colours participants are using.
For Trial 3, the MS NetMeeting shared whiteboard was tested with a view to using it. This was because the earlier studies, had shown that drawing operations were useful in textual work and suggested that a shared whiteboard would be preferable to a text editor. However, when tested with multiple users, the tool displayed some erratic behaviour (uneven delays in updating displays, inconsistent placing o f images on different computers). It was believed that such behaviour would make the students distrustful o f the tool and be detrimental both to the learning and to the research. It was therefore decided to continue using
Network Text Editor, nte (Handley & Crowcroft, 1997). The editor was modified slightly: the font size
could be changed (this had been requested by participants in Trials 1 and 2 and the ancillary investigations).