The document discusses the complexities and structures of hypertext and multimedia on the web, highlighting the nonlinear nature of hypertext and the challenges it presents, such as 'lost in hyperspace.' It explains the evolution of web technology from static to dynamic content, emphasizing the importance of designing better navigation and understanding users' locations within hypertext. Additionally, it touches on interaction models and the distinctions between status and event phenomena in user interfaces.

1. UNIT - 5
INTERFACING APPLICATIONS

2. GROUPWARE

3. GROUPWARE

9. HYPERTEXT, MULTIMEDIA AND THE WORLD
WIDE WEB
• Understanding Hyper text
• What is the hyper?- it includes rich contents:
graphics, audio, video, computation, and
interaction
• The traditional texts share a common linear
nature.
• This linearity is partly because of the nature of the
media used
• Text imposes strict linear progression on reader

10. HYPERTEXT, MULTIMEDIA AND THE WORLD
WIDE WEB

11. HYPERTEXT, MULTIMEDIA AND THE WORLD
WIDE WEB

12. Issues/Finding things in Hyper text
• Lost in Hyperspace
• Even though the non-linear structure of
hypertext is very powerful, it can also be
confusing.
• It is easy to lose track of where you are, a
problem that has been called ‘lost in hyperspace’.
• There are two elements to this feeling of
‘lostness’.

13. Cognitive and related to content
• The reader can browse the text in any order.
Each page or node has to be written virtually
independently, but, of course, in reality it
cannot be written entirely without any
assumption of prior knowledge.
• Once the reader encounters fragmentary
information, it cannot be properly integrated,
leading to confusion about the topic.

14. Navigation and Structure
• The hypertext may have a hierarchical or other
structure, the user may navigate by hyperlinks that
move across this main structure.
• It is easy to lose track of where you are and where you
have been.
• The solution to the former issue is to design the
information better.
• The solution to the latter is to give users better ways
of understanding where they are and of navigating in
the hypertext.

15. Web Technology and Issues
• The web consists of a set of protocols built on top of the
internet that, in theory, allow multimedia documents to be
created and read from any connected computer in the world.
• The web supports hypertext, graphics, sound and movies,
and, to structure and describe the information, uses a
language called HTML (hypertext markup language) or in
some cases, XML (extensible markup language).
• HTML is a markup language that allows hypertext links,
images, sounds and movies to be embedded into text, and it
provides some facilities for describing how these
components are laid out

16. Web Technology and Issues

17. Network issues

18. Static Web Contents

19. Static Web Contents

20. Dynamic Web Contents
• In the early days, the web was simply a collection
of (largely text) pages linked together.
• The material was static or slowly changing and
much of it authored and updated by hand.
• As HCI researchers and designers, we can neither
ignore nor uncritically accept new technology in
the web.
• The active web is here, our job is to understand it
and to learn how to use it appropriately

21. Fixed Content- Local Interaction and
Changing views

22. Other interaction models
• The PIE model was the inspiration for a wide variety of different
models.
• Some of these are similar, but take a slightly different
standpoint.
• For example, one model has results only available at some states.
• This actually corresponds to the intuition that a printed
document is only available when you invoke the print function,
or that an updated file is only available in the file system when
you ask the editor to save.
• However, that model also only had the display available at some
states – less intuitive

23. CONTINUOUS BEHAVIOR
• Although many of the systems and interfaces studied in
rich media and in novel interfaces embody continuous
real-time interaction, there are few models of this in the
HCI literature.
• Possibly this is because of the conceptual dominance of
discrete models.
• At a low level, computer systems are clearly discrete with
step-by-step programs and users’ actions being converted
into streams of events.
• Even apparently smooth actions like dragging a mouse are
treated as a series of individual ‘mouse has moved’ events.

24. Dealing with the mouse
• The PIE model is very asymmetric between input and output. Some
sorts of output are difficult to deal with, for example a beep used
when something goes wrong.
• This is not clear in the formalism itself, but if we look at the
principles, it is obvious that the display is expected to be persistent.
• If you go away and have a cup of tea, the display is still there when
you get back.
• The beep is not. On the input side, mouse movement is not easy:
one can regard each movement as being a command in C, but this
is unnatural.
• Certainly, the user would not be conscious of each pixel movement!

25. Formal aspects of status–event analysis
• Probably the earliest continuous time models in the formal user
interface literature are the variants of status–event analysis [94,102] of
which the variant of the PIE model above is a simple example.
• Status–event analysis (S–E) distinguishes events that occur at specific
moments of time from status phenomena that have (typically
changing) values over a period of time.
• Examples of events include keystrokes, beeps, and the stroke of
midnight in the story of Cinderella.
• Examples of status phenomena include the current computer display,
the location of the mouse pointer, the internal state of the computer
and the weather.
• We will discuss status–event analysis in more detail in Chapter 18;
here we will just look at the more formal aspects.

26. THANK YOU