A talk at UPA NJ on 16 March 2011.

1. User‐centered Informa0on Modeling
Bruce Esrig
Talk at UPA NJ, 16 March 2011

2. User‐centered informa0on modeling
In order to design a solu0on, let’s ...
• Tell the stories that maFer to our actors because of their goals.
• Read the stories for informa0on about their tasks and the
knowledge they need to work with
• Formalize some of the concepts that occur in the stories
• Organize the concepts using meaningful structural
rela0onships
• Annotate the rela0onships with logical implica0ons
• Check the results against the stories
Bruce Esrig. Talk at UPA NJ, 16 March 2011 2

3. Warmup
• Informa0on modeling
• Knowledge representa0on (will expand)
• Goals and tasks
• Stories
• Actors
• User‐centered informa0on modeling
Bruce Esrig. Talk at UPA NJ, 16 March 2011 3

4. Informa0on modeling
Informa0on modeling is the art of finding out what you
need to talk about and how it is structured
Bruce Esrig. Talk at UPA NJ, 16 March 2011 4

5. Knowledge representa0on
Knowledge representa0on is the aFempt to capture
essen0al concepts, individuals, and the rela0onships
among them as data
• Tabular data
• Tree‐structured data
• Diagrams with bubbles or boxes, lines, labels, and
layout
• Seman0c web or linked data
Bruce Esrig. Talk at UPA NJ, 16 March 2011 5

6. Goals and tasks
Goals are the things that users or other actors wish to
accomplish.
Tasks are the sequences of steps they can use to
accomplish them.
• For today, let’s ignore postures, such as appealing
helplessness, and the whole subject of persuasion, i.e.
inspiring others to want what you want.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 6

7. Stories
Stories explain paths that users and other actors follow
from wherever they may be to a different condi0on in
which their goal is achieved.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 7

8. Actors
Actors are the players in the story.
• Their quali0es, behaviors, and interac0ons may be modeled,
but that is not the kind of informa0on we are modeling today.
• Instead, we are focusing on informa0on about the domain
under discussion and working to understand how the stories
and the actors inform us about the structure of that
informa0on.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 8

9. Knowledge representa0on
• In the beginning ...
• Iden0ty
• Types
• AFributes
• Rela0onships
Bruce Esrig. Talk at UPA NJ, 16 March 2011 9

10. In the beginning ...
The things we wish to talk about are undifferen0ated. We may recognize them,
but we don’t know what they are, or anything about them. We may even share
a common experience of one of them and s0ll not have a name for it.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 10

11. Iden0ty
1
2
3
4
5
6
7
8
9
To represent knowledge, we must find something to write down to represent
each thing or phenomenon that we know about and wish to model.
The root of knowledge modeling is establishing iden0ty. We need a way of
agreeing on which item is which.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 11

12. Types
Un0l now, we’ve said nothing about what the items in the model can be. They
could be individuals, concepts, events, phenomena, quali0es, constraints, ...
A simple technique for organizing items is to find similari0es among them and
define groupings that each of which contains only items that are similar in a
certain regard. We might call such a grouping a type (or a concept).
Bruce Esrig. Talk at UPA NJ, 16 March 2011 12

13. Types and Iden0ty
1
2
3
4
5
6
7
8
9
Types can be built by finding the individuals that belong to the type. You could
imagine iden0fying a batch of individuals, and considering those that meet
certain selec0on criteria to be part of the type.
Alterna0vely, you might start with a descrip0on, and only later find out which
individuals fit the descrip0on, if any.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 13

14. AFributes
18
32
23
Color: green
7
Texture: rough
Loca0on: (geo‐coordinates)
Neighbor: Item 18
Type: (simple type such as green dot or
pointer into type hierarchy, such as Dot > Green)
Some aFributes have simple values that you may not be
modeling as individuals, such as the names of colors or textures.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 14

15. Rela0onships
18
32
23
Color: green
7
Texture: rough
Loca0on: (geo‐coordinates)
Neighbor: Item 18
Type: (simple type such as green dot or
pointer into type hierarchy, such as Dot > Green)
We say we have a rela0onship when
the related value is an individual in the model.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 15

16. References
• Mental Models (Indi Young)
• Informa0on Architecture for the WWW
• Informa0on Modeling Concepts and Guidelines
• The UML Language Reference Manual
• Seman0c Web for the Working Ontologist
• Designing for Naviga0on
• Mental Notes cards (what we’re not talking about)
Bruce Esrig. Talk at UPA NJ, 16 March 2011 16

17. User‐centered informa0on modeling
In order to design a solu0on, let’s try to ...
• Tell the stories that maFer to our actors because of their goals.
• Read the stories for informa0on about their tasks and the
knowledge they need to work with
• Formalize some of the concepts that occur in the stories
• Organize the concepts using meaningful structural
rela0onships
• Annotate the rela0onships with logical implica0ons
• Check the results against the stories
Bruce Esrig. Talk at UPA NJ, 16 March 2011 17

18. Agenda
• Problem statement (qualita0ve)
• Analyzing the problem statement
• Problem statement (formal)
• Method
• Applica0on of method
• Exercise
• Solu0on
• Case study
Bruce Esrig. Talk at UPA NJ, 16 March 2011 18

19. Problem statement (qualita0ve)
Suppose (just suppose) that a child has a computer,
school work to do on the computer, and a desire to play.
The same computer can be used to work or play, so a
parent wishes to structure the situa0on.
Can we design sohware that will dis0nguish between
work ac0vi0es and play ac0vi0es, and keep track of
0me, to structure the ac0vity on behalf of the parent?
Bruce Esrig. Talk at UPA NJ, 16 March 2011 19

20. Problem statement (qualita0ve)
Complica0ons:
• Work and play may be interleaved
• Some 0mes are too early and too late
• How to decide what sites are allowed for work and for play
• What if the system decides incorrectly?
Complica0ons excluded from the discussion:
• More computers in the house
• More users in the family
Bruce Esrig. Talk at UPA NJ, 16 March 2011 20

21. Analyzing the problem statement
User
• Goals and tasks
• Objects manipulated
• Model of objects
• Func0ons that affect objects
Bruce Esrig. Talk at UPA NJ, 16 March 2011 21

22. Analyzing the problem statement (example)
Parent
• Goal: Control access to the internet
• Objects: Web sites
• Model: Web site has subject maFer
• Func0ons: Allow/block web site
Bruce Esrig. Talk at UPA NJ, 16 March 2011 22

23. Problem statement (formal)
An applica0on is needed that controls Internet access
for various audiences.
Access to a site is based on the subjects that appear on
the site.
Create a model that illustrates the informa0on
rela0onships among audiences, sites, and subjects.
Bruce Esrig. Talk at UPA NJ, 16 March 2011 23

24. Method
• State model in more detail
– Types of objects
– Proper0es of objects of each type
– Rela0onships among types of objects
• Apply model and test it out
• Refine (or debug!) as needed
Bruce Esrig. Talk at UPA NJ, 16 March 2011 24

25. Applica0on: Define objects
Users Sites
Bruce Esrig, Talk at UPA NJ, 16 March 2011 25

26. Applica0on: Define aFributes
Users Subjects Sites
Bruce Esrig, Talk at UPA NJ, 16 March 2011 26

27. Applica0on: Define aFributes
People Sites
Subjects Subjects
People are interested in subjects Sites are about subjects
Bruce Esrig, Talk at UPA NJ, 16 March 2011 27

28. Applica0on: Define rela0onships
Person Site
then the site is allowed
for the person.
Subjects Subjects
If all subjects the site is about
are allowed for the person,
Person is allowed to view subjects Site is about subjects
Our conceptual model of the world has people and sites.
Our analysis model examines a person and a site.
Bruce Esrig, Talk at UPA NJ, 16 March 2011 28

29. Applica0on: Define rela0onships
User Site
then the site is allowed
for the user.
Subjects Subjects
If all subjects the site is about
are allowed for the user,
User is allowed to view subjects Site is about subjects
Aboutness is actually calculated by analyzing subjects
that are men0oned on pages at a domain.
Then all the subjects that appear on a site are
aFributed to the site.
Bruce Esrig, Talk at UPA NJ, 16 March 2011 29

30. Applica0on: Define rela0onships
User Site
then the site is allowed
for the user.
Subjects Subjects
If all subjects the site men0ons
are allowed for the persona,
User is allowed to view subjects Site men$ons subjects
What we are thinking about changes from people (in general),
to person (in par0cular), to user (thinking about the system), and
next to persona (thinking about a way that a person uses a system).
Bruce Esrig, Talk at UPA NJ, 16 March 2011 30

31. Applica0on: Define rela0onships
Persona Site
then the site is allowed
for the persona.
Subjects Subjects
If all subjects the site men0ons
are allowed for the persona,
Persona is allowed to view subjects Site men0ons subjects
(In this par0cular example, one user account can serve one or more
people on one or more computers by giving each person one or
more personas.)
Bruce Esrig, Talk at UPA NJ, 16 March 2011 31

32. User‐centered informa0on modeling
In order to design a solu0on, we ...
• Tell the stories that maFer to our actors because of their goals.
• Read the stories for informa0on about their tasks and the
knowledge they need to work with
• Formalize some of the concepts that occur in the stories
• Organize the concepts using meaningful structural
rela0onships
• Annotate the rela0onships with logical implica0ons
• Check the results against the stories
Bruce Esrig. Talk at UPA NJ, 16 March 2011 32

33. Interes0ng surprises
• Wikipedia.com and wikipedia.org have to be entered
as separate excep0ons (to allow access).
• Gmail contains media and entertainment, so a parent
can’t rule out all media and entertainment and s0ll
allow a child to use Gmail while doing homework.
• Kids accept an amazing variety of game sites ...
hFps://www.cia.gov/kids‐page/games/index.html
Bruce Esrig. Talk at UPA NJ, 16 March 2011 33

34. Exercise
Add one constraint:
• Time bounds per audience
Bruce Esrig. Talk at UPA NJ, 16 March 2011 34

35. Solu0on: Define aFributes
Persona Site
Subjects Subjects
Time Time of day,
constraint Elapsed 0me
Bruce Esrig, Talk at UPA NJ, 16 March 2011 35

36. Solu0on: Define objects
Persona Site
Subjects Subjects
Clock and
Timer
Time Time of day,
constraint Elapsed 0me
Bruce Esrig, Talk at UPA NJ, 16 March 2011 36

37. Solu0on: Define rela0onships
Persona Site
then the site is allowed
for the persona.
Subjects Subjects
If all site subjects are allowed
for the persona
Clock and
Timer
AND
Time Time is within bounds Time of day,
constraint Elapsed 0me
Bruce Esrig, Talk at UPA NJ, 16 March 2011 37

38. Case study
Mul$ple Persona Site
personas Site is allowed
per
user
account
Subjects Subjects
All site subjects are allowed
User account
(1) Some sites contain a mix of allowed
and not‐allowed subjects.
(2) Some$mes the constraint is on the Timer Clock
reason for use (entertainment vs
study), not the subject.
Time AND
Elapsed 0me
constraint
Elapsed 0me is within bounds
AND
Time
Time of day is within bounds Time of day
constraint
Need two user accounts because diff people have diff $me constraints
Bruce Esrig, Talk at UPA NJ, 16 March 2011 38