SWT - Diagrammatics
Lecture 1/4 - Introduction to Diagrams
25-April-2000
Introduction
• My name is Athanasios Tsintsifas,
for short just Thanassis...
• I am a Ph.D. student and a member of the LTR department
of the University of Nottingham.
• I have contributed in the development of CourseMaster
and created the Daidalos system as part of my research.
• You can reach me at:
[email protected]
• I have a page at
:
http://www.cs.nott.ac.uk/~azt
• You‘ll be able to find each lecture’s notes in :
– www.cs.nott.ac.uk/~azt/diagrammatics/index.html
LTR
• Learning Technology Research (LTR)
• The LTR group is focusing its research in finding ways to
facilitate teaching and enhance the learning experience.
• For the last three years, LTR has been developing the
CourseMaster system.
• The Ceilidh system, the ancestor of CourseMaster, has
been in use for over 10 years by more than 100
WWW
Diagrammatical
universities in the world.
Interface,
Assessment
Prolog
Pascal SQL
First
version,
C module
1988
Ceilidh 2,
SML
C, C++
modules
1990
1992
X-Interface,
Software-Tools
1995
Z
Course
Master
CD-ROM
Java
1998 1999
2000
Automatic Assessment Categories
• Two types of assessment :
– Fixed response :
• Multiple Choices,
• Questionnaires
– Free response :
•
•
•
•
Programming languages,
Essays,
Graphics,
Diagramming
• The Ceilidh system has been assessing both fixed and free response
coursework.
• With CourseMaster and Daidalos graphical and diagramming
exercises can be assessed too!
Problems that needed overcoming
• Graphics and Diagramming based exercise poses inherent
problems to a system for automatic assessment :
– Each domain needs its own :
• graphical editor,
• assessement metrics
– Domain editors are complex to create.
– Generic editors are unable to retain extra information that is needed
for diagrammatic assessment of coursework.
• The setting of an automatically assessed graphical exercise is
a complex process that requires the cooperation of many
users.
The Approach
Daidalos
Ariadne
Theseus
DATSYS system
CM Clients CM servers
CourseMaster system
Java platform
Operating Systems: Windows 95, 98, NT, 2000, Solaris, Linux
The Approach
• DATsys is a Object Oriented Framework encapsulating the
design of a family of diagramming editors.
• Daidalos, Ariadne and Theseus are composed with parts of
the same framework. :
– Daidalos provides facilities to design graphically domain component
libraries.
– Ariadne provides facilities to automatically generate the student
diagrammatic editor (Theseus) using Daidalos’s libraries and the
required marking specification.
– Theseus is used by the students in order to design their diagrams
and can be generated independently for each exercise, unit or
course.
Daidalos
A Generated Theseus
What we will be covering :
• There will be three more lectures on diagramming and three
exercises in total:
– (D1) Introduction to Diagrams,
– (D2) Diagrams in Sciences and CS - Logic Diagrams,
– (E1) Two logic circuit exercises
– (D3) Diagrams for Software Development
– (D4) OO Diagramming / UML / Meta-diagramming
– (E2) One OO design exercise
(D1)
(D2)
(E1)
Tuesday Thursday Friday
25/04
27/04
28/04
(D3)
(D4)
(E2)
Tuesday
02/05
Thursday
04/05
Friday
05/05
What we will be covering :
• First lecture :
– Introduction - definitions
– A historical review
– Diagram advantages
– Diagram universal properties
– Diagram origins
– Important diagrammatic domains
What we will be covering :
• Second lecture :
– Diagram Distinctions,
– Flowcharts, Nassi-Shneiderman Diagrams,
– Structure Diagrams, Dataflow Diagrams
– Software Level Charts, Cell-Arrow Diagrams
– State Transmission Diagrams, Petri Nets,
– Logic Gates, Logic Circuits, Venn Diagrams
– Entity-Relationship Diagrams
What we will be covering :
• Exercise week 1:
– Exercise Lift: This is a simple exercise, in which you'll
have to design the logic circuit which will operate a
lift using logic gates.
– Exercise Nuclear:This is a more advanced exercise,
in which you'll have to design the logic circuit which
controls the launch of nuclear weapons (albeit a
simplified one!)
What we will be covering :
• Third lecture :
– OO Design Notations, Objects,
– Messages / Control & Data Flow, Classes
– Class Attributes and Operations
– Visibility of Attributes and Operations
– Relationships: Association, Multiplicity
– Relationships: Aggregation
– Relationships: Dependency
– Relationships: Inheritance
What we will be covering :
• Fourth lecture :
– UML diagramming
– Object diagrams with UML
– Class diagrams with UML
– OO Developments
– Meta-Diagramming
– Software Demonstrations
– How to Proceed / Further Information
What we will be covering :
• Exercise week 2
– Exercise hotel: This is a simple exercise, in which
you'll have to design (not implement) a class
diagram for a hotel room booking system. You will
be using a similar to UML notation.
Dia-gramm(a),(h),(wn)
to - line
to convey a message by means of drawing lines.
Representation
More
Arbitrary
TEXT
PICTURES
DIAGRAMS
More
Homomorphic
Diagram
• James Maxwell's definition (Encyclopedia Brittanica,
11th edition): a figure drawn in such a manner that the
geometrical relations between the parts of the figure
illustrate relations between other objects.
Diagrams are :
• In general, representations of things, thoughts and
relationships that usually :
– attempt to present information in a concise, clear and
understandable way,
– try to convey information using a specific notation or not,
– can present non-visual information in a visual form,
– can depend on agreed conventions, like written text, but their
overall form affects their interpretation.
History of Diagrams
• The earliest abstract illustrations are maps.
• Maps relate physical distances between locations in the
world and physical distances of these locations on paper.
• By their nature, they abstract out detail (e.g. roads are
represented by straight lines, coastlines are abbreviated etc)
• The map is not the territory...?
The History of Diagrams
• Geometric diagrams have been around for quite some
time : Manuscripts containing proofs with diagrams of
the Pythagorean theorem exist from the time of ancient
Greeks -These diagrams are also based on a concept
of metric space.
• Descartes' invented the Cartesian coordinate
system in the 17th century.
• Scientific discoveries in physics and chemistry resulted
in increasingly abstract diagrams.
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The History of Diagrams
• Topological diagrams: their history is difficult
to trace.
• In the middle ages, hierarchies of trees were
used to document lineage.
• Religion and cosmology of the middle ages
made great use of diagrams, including graphs.
• In the Renaissance, the rediscovery of Greek
thought resulted in many diagrams of
philosophical and scientific nature - mostly for
illustration purposes .
The History of Diagrams
• In the 19th century, the work of Boole inspired the
invention of Venn diagrams.
A
B
• Charles Peirce extended these
and invented existential graphs :
• The explosion of abstract mathematics
resulted in the proliferation of tree and graph
representations.
For some tasks diagramming works better
x
i
y
o
SP(I,O) xy : delay(I, y)  not(I, x)  and(y, x, O)
delay(I, O)  t : O(t+1) = I(t)
not(I,O)  t : O(t) = 1 - I(t)
and(I1, I2, O)  t : O(t) = I1(t) x I2 (t)
Two representations that describe a configuration of the same single
pulser.
Advantages of diagramming
• Many comparisons of verbal and visual tasks have
shown that human capabilities differ in the way they are
distributed through the brain: different people choose
different strategies to accomplish the same tasks.
• Although there appear to be differences between the
strategies that individuals choose in visual reasoning
tasks, strategy is also affected by education, expertise
and culture.
• Furthermore, topological complexity of a diagram
affects the performance of an individual.
Advantages of diagramming
• Advocates of diagrams have suggested that the right
hemisphere of the brain is "needlessly at rest and
underutilised" when using text-only notation for
descriptions.
• Research has also shown that some simple visual tasks
can require more time when carried out by the left
hemisphere.
• There are many tasks in which verbal and visual
information is combined. Research has shown that
memory improves when a concrete image can be
associated with a task (e.g. for navigation purposes:
route memory depends on visual landmarks)
Universal Properties
• However, even if many diagrams rely on expert
knowledge, diagrams have many universal properties:
– Adults from all cultures show quantity increasing from bottom
to top of a page.
– Time direction is always from left to right.
– Everybody can be aware that an
object is related to another object
just by observing at the connectivity
between the two; it doesn’t matter
what kind of connection it is as long
as the connection is described as a
kind of a line.
– Any more universal properties?
Diagrams are based on origins of :
• Resemblance: The most naive account (more likely to be
made of diagrams with a strongly pictorial element) is simply
that they resemble the things they refer to.
• Metaphor: It is possible to depict things that do not exist
physically, that we, humans, have a mental image of them
(e.g. abstract concepts, or structure representations in
computer systems)
• Concrete Descriptions: By abstracting physical entities we
can get a better picture of the world around us.
Diagrams offer :
• Locality and Labels: Diagrams group related information in
the same area, so searches can be constrained to the scope
of a goal. Correspondences can also be established from
topological relationships.
• Expressive Power and Specificity: Diagrams allow multiple
layer abstraction. They have fewer interpretations than
unconstrained textual notations.
• Pragmatics: Diagrams provide a “vocabulary” for discussing
the way that notations are interpreted. Every notation
highlights some kind of information and obscures other
aspects in which we are not interested in at that moment.
Diagram use :
• Applied psychology uses diagrams as a way to learn
about the nature of cognition, and analyses how
different diagram types and diagram features affect
human problem solving.
• Cognitive science: the use of computer models allows
researchers to propose and investigate systematic (and
potentially formalisable) models of reasoning. Cognitive
science is focused on definite descriptions of
diagrammatic reasoning tasks and investigates how can
these models accommodate analogue representations
rather than symbolic logic ones.
Diagram use :
• Linguistics is also using in diagrams in their quest to
analyse syntax, semantics, and pragmatics of spoken
languages.
• Computational linguistics is using diagrams to depict
information that enables research analogous to the
research on verbal language e.g. formulation of grammars
that allow automatic parsing and generation of diagrams.
• Visual programming promises to make programming
accessible to more people via the use of diagrams.
Diagram use :
• Data visualisation: as most diagrams
are created by a person with a communicative intent and an understanding
of the expected reader, data visualisation
diagrams help with the characterisation of
data and formalisation of design rules in
order to facilitate the user (e.g. in helping
a programmer to write code).
• Graphic design uses diagrams in order to facilitate the
task of a graphic designer to accept a given set of
information, who can then prepare a way of
communicating that information effectively.
Diagram use :
• Education uses diagrams in order to facilitate education
and teaching in all subjects. Education is concerned with
finding out which types of diagrams are appropriate for
what teaching goals. Learning concepts diagrammatically
can help to solidify abstract concepts.
• History and philosophy of science: Scientific discovery
has often been associated with novel uses of
representations (such as algebra or Cartesian
coordinates). Past discoveries have largely been founded
on diagrams.
Diagram use :
• Architecture: Architects spend much of their time working
with visual representations, although their most common
representation is the sketch. Diagrams support
architectural problem solving and facilitate the creativity
that architects experience when sketching
• Management - Brainstorming: Mind mapping techniques
use diagrams in order to categorise tasks, to help people
remember better and to provide a visual path to the tasks
that need to be performed.
Diagram use :
• computer science and engineering: diagrams are used
to great extent in order to facilitate information sharing,
information filtering and understanding of complex notions.
• Biology & Genetics
Cytochrome P450
Oxidoreductase
Ribbon structure of MCAD monomer
with C8-CoA complex
The end of lecture 1