presented by Kavé Salamatian, Professeur à l’université de Savoie at 

1. Kavé Salamatian
Professeur à l’université de Savoie

2. Big Data : great expectations

3. Big Data is the name for what ?
Capture storage of massive amount
of data
Diverse, heterogeneouse, imperfect
Data processing
Sanitisation
Statistical models
Co-occurrences/correlations
Uncertainty structure
Specialisation
Model application to specific
individuals
Action
Intelligent behaviour

6. What is new
Processing and storage capacity
Hardware, databases, langages
Data science
Statistics, data fusion,
Absence of purpose
“From application to data” vs. “From
data to applications”
Massive application to individuals
Statistics is for groups
But motivatiuon remains the same
"scientia potentia est”
Money is power

7. What about ethics ?
Where is ethics ?
In code writing?
In executing the code?
In modelling ?

8. On the use of computers in real
world

9. About statistics
There is no statistics but
statistical models
Some are useful, all are
wrong

10. From power to “power laws”
P(k) ~ k -γ

11. S.cerevisiae
k
n(k)
1 2 3 4 6 8 11 16 23 33 47 67 95 141 220
1 2 3 5 8 16 33 56 111 210 535 1248
Figure 1: Yeast protein interaction data (o) and best-fit probability distribu-tions:

12. Seneca already did criticisms of Big data
Is not Big Data the haruspicine of nowadays etruscans

13. Should we regress when we do
regression ?

14. A fairy tale
Once upon a time there was a complex reality …
To understand it people make fable out of it …
After a while people believed the fable and forget about the reality
Same story frequently happen in science
Once upon a time there was a complicated reality
After a while people build a model to understand it
Later people forgot about the reality and thought that the model is the
reality
The model became real … and the troll eat the princess J
You always need to have critical view about what a model predict
Sometimes it is relevant to reality, sometimes not.
The role of the scientist is to filter out what is relevant from what is not

15. The quest for objectivity
Finally what is objective
We throw a coin
The probability of the model is p
Pr{10th throw is face}=p
Application to individuals can only be subjective

16. This is risky to go in bed with
procuste

17. Hannah Arendt and the ideosyncrate …

18. Hannah Arendt and the ideosyncrate …
What is totalitarianism?... A power-hungry group achieves power --
using demagogic means to maintain and expand its unlimited and
unchecked power. These means are particularly terrifying and efficient
and our time because of technical progress and inventions which
permits swift concentration and application of power and manipulation
as well as production of public opinion. There are no truly
representative subleaders, there are no independent social groups, no
traditional rights, no historical contributions and merits which can
check the modern absolute totalitarian rulers; it must be emphasized
that the totalitarian system differs from old-fashioned despotism and
autocracy in its use of economic and technological pressures and
manifestations of so-called public opinion. The totalitarian tyrannies of
our time do not appeal to the "divine right," but they claim to represent
the true will of the masses and of the people. They like to characterize
themselves as representing the "real country" against legalistic fictions
of democracies which destroy the unity of the people and paralyze it by
parties, the instruments of parasitic and egoistic particular interests.
They present themselves as "true" democracies because, for instance,
only the communistic party (which allegedly is identical with the
working productive masses) exists; whereas all exploiters and their
representatives are suppressed. . . .

19. Invisible hand ?
“Ever& individual... neither intends to promote the
public interest, nor knows how much he is
promoting it... he intends only his own securit&;
and by directing that indust=& in such a manner
as its produce may be of the g=eatest value, he
intends only his own gain, and he is in this, as in
many other cases, led by an invisible hand to
promote an end which was no par? of his
intention.”
The wealth of Nations, Adam Smith

20. So what’s economy ?
“Economy is the stAdy of the use of scarce
resources which have alterBative usages “
Lionel Robbins (1898-1984)

21. 1 billion $ question
How are scarce resources assigned
between alternative users ?
Price
Parity between offer and demand

22. Foundations !
Walras
Pioneered equilibrium theory
Conjectured existence of equilibrium
prices
Stated that network should be at
equilibrium
Prices such that supply match demand
What happens when ?
multiple goods
multiple buyers
Different desires
Different buying power

23. Equilibrium
Two problems
Price are set, how much I can
buy ?
Such that total utility is
maximized
Quantities are defined, what
is the equilibrium price ?
Total utility maximization
pi pi
pi

24. Arrow-Debreu Theorem
Established existence of
equilibrium in a very
general setting
Competitive equilibrium is
Pareto optimal
Every Pareto optimal
allocation comes from a
Competitive equilibrium

25. What about data ?
Economy is the science of
sharing rare resources
Information is different from
other goods
Follow the second law of
thermodynamic
No conservation law

26. The devil is the details
Assumption about goods
and services
They are rare and finite
One cannot reproduce them and
negligible cost
The added value utility is
predictable
Unless for innovations or
monopoly
Information lack all of these
It is not rare
Creating information is costly but
one can reproduce it at low cost
The added value is unpredictable
Information is very flexible

27. 1 Million $ question
How can we evaluate
the value of a .com ?
How can we evaluate
the value of private
information ?
How can we predict
network growth based
on economical
premices?

28. A new micro-economical theory ?
The insider traders view
the value of money that somebody can gain by knowing this piece of
information
The thermodynamic model
the value of information as the price of the energy needed to create it
The information market view
You can only trade information with information
No monetary value

29. What is a network ?
Seems a trivial question, …,
but no clear consensus on the
answer.
Each community has it own
definitions
Still network is so universal
that they should be
commonalities
Challenge
Can we make a generic
definition of network that
Integrates all network
Still let enough freedom for
their differences.

30. What is transported by a network ?
Some network clearly transport goods
Road network, silk road, grid network,
metabolic network, etc.
We will name them goods network
Some network do not transport goods
Citation network, social network, etc
A lot of these network transport
“Information”
Internet Indeed, but also citation networks,
social network, etc
We call them Information network
Frequently intertwined with goods network
power grid where the network
transporting energy is coupled with a
control network used manage the energy
flow
commercial network (like the Silk Road)
where goods are transported along with
the seller handling the commercial
information.
Sometime no clear information network
Electrical circuit

31. Logistic vs. Information networks ?
Any Logistic network have or had
an associated information network
that was used for growing it
For some case the information
network associated with a goods
network disappear later when the
network get ossified
Where the network is still growing
and dynamic the information
network is still here.
One has to analyse the associated
information network to understand
the goods network resulting from it.
I believe that one can consider as a
network, only the information
network.

32. So … what is a network
A network consists
of a set of
distributed elements
that are cooperating
to exchange
information
An information exchange
market
Several ill defined term
Cooperation
Information …
Internet is a network that strictly
exchange information in Shannon terms
Other network might transport other type
of information
Migration network transporting DNA

33. Information theory …
Is not a theory of coding information
Does not tell how much information is send
It is the theory of cooperation
It limits the rate of uncertainty reduction that a use of a communication channel
provides
Side information : get the bit that complete the picture
Simplicity theory : what is interesting ? What reduce the most the Kolmogorov
complexity
simplicity corresponds in a drop in Kolmogorov complexity
Information theory is a theory of cooperation
Error Control Coding tells how to arrange transmission such that each one
cooperate with others
Separation principle : one can separate transmission from processing
Foundation of layering and net neutrality
Valid for point to point, not valid for multi-point
Cross-layering needed when resources are scarce

34. Cooperation ?
Full Cooperation
¨ Do the best possible behavior
to reach a goal
¤ Assuming full collaboration
Is the goal achievable ?
How to achieve the goal ?
Multi-user information Theory
Non–cooperative
Selfish behavior
Different rational goal
How to mitigate conflicting
rational goal ?
Game theory
Malicious behavior
Harmful goal
How to contain irrational
objectives ?
Behavioral inference

35. What about privacy ?
• Privacy is an economic
problem… even when
privacy issues may not have
direct economic
interpretation
• Privacy is about trade-offs:
pros/cons of revealing/
accessing personal
information
– Individuals
– Organizations
• … and trade-offs are the
realm of economics

36. Privacy… But at the price of accuracy
§ You don’t want to like things that have absolutely nothing to
do with your real interests.
§ In fact, your data are also used by your friends,
advertisements, recommender systems, etc…
§ Preserve usability of the applications that run on your
data
§ If we do not know what application the data will be used
for: Need general distortion constraints!
Privacy-utility trade-off
36

37. Prisoners dilemma
A simple game that has become the
dominant paradigm for social scientists
since it was invented about 1960.
Game theoretic problems: payoffs for each
player depend on actions of both
Two possible strategies: A party cooperates
when he performs value-increasing promises,
and defects when he breaches
While cooperation is collectively rational,
defection is individually rational.
Player 2
Cooperate Defect
Cooperate Both
cooperate
Player 1
cooperates,
Player 2
defects
Defect
Player 1
defects,
Player 2
cooperates
Both defect
Player 1
Cooperate Defect
Cooperate 3, 3 -1, 4
Defect 4, -1 0, 0

38. Iterated Prisoner’s Dilemma
IPD
n-stages;
n is known or not
Backward induction;
Nash equilibrium;
Strategies
Tit for Tat
Tit for Two Tat
Suspicious Tit for Tat
Free Rider
Always Cooperate
Axelrod’s Tournament
Altruistic strategies does better
Networks extend the possibility of
cooperation between N actors from
O(N2 ) to O(2N)
38

39. Net Neutrality Question
Net Neutrality is not just a question of access network
It has to deal with cooperation between all actors in Internet
Content provider/ISP
ISP/ISP
End Users/ISP
End Users/Content Provider
End Users/End Users
Opacity generate Prisoner Dilemma
Defection is the default
How to improve cooperation
Improve transparency

40. Is surveillance an addition to
networks or is it intrinsic ?

41. Conclusions
There is a new science emerging :Internet Science
We are still searching for its fundaments and principles
This new science is highly multidisciplinary
Multidisciplinary research is tough and odd
A large part of this work has resulted from discussions and
exchange with members of the European Network of
Excellence EINS funded under FP7 Fire activity.
www.internet-science.eu