SlideShare a Scribd company logo
Statistical Physics, Network
theory & Big data
An approach to human mobility

Oleguer Sagarra
Dept. Física Fonamental,
University of Barcelona
1
A killing combination...
Statistical Physics
&
Big Data
“New Social Sciences”
2
Why?
We want to study Human Mobility…

Mobility has deep implications in many processes..
(contagion, spread of ideas...)
The development of GPS/mobile phone technologies
makes gathering data cheap and possible at large
scale.
3
What?
(Human) Mobility is a rather complex process…
Different scales (Micro/Meso/Macro)
Society is heterogeneous… (Humans are not
“monkeys”… in principle!)

But we are physicists! So we will try to
model it anyway…
4
But we don’t need
modelling…
“Computers are useless, they can only
give you answers…” (P. Picasso)
This talk is about questions rather…
“Models push the boundaries of our
understanding"
5
How?
Theoretical
Physics
Mathematics

Empirical
Real (big) Data

Network Science

6
The data... (has problems)
a) How to get it?
Private companies
(Social Media)

Citizens

7
Getting the data... Experiments
Smartphones give lots of “sensing opportunities”
Citizen science aims to involve people in data
collection, sharing and processing

BeePath: Experiments on
human mobility
http://bee-path.net
(Btw: Very interesting project, but don’t have time for it today)

8
Getting the data...
Social Media
b) Is it biased?
(Big data can also mean big errors)

9
Social media data
Social media data is geolocalized, we can extract
trajectories from it.
But first, is the data representative from the population?

(We want info about people, not about “some people that tweet a lot”)

We can compare with the census…
Analysis must be done at user level!
10
The data... is geolocalized,
and (too) big!
c) Continuous vs discrete data
From points to a network?
(We want only the flows: From where and to where people go, “on average”)

11
The network approach
Data
Filtering
Aggregation (grid)
Network

12
Network data

(We can now apply network metrics
and… data is normalized!)
Sagarra, O. Master Thesis. http://upcommons.upc.edu/pfc/handle/
2099.1/13134

13
Now we know how to deal
with the data...

We want to detect “abnormal” patterns...
What is chance, what is not?
What is important, what is not?
14
Modeling as a physicist…
Take all trivial elements out…
Keep just the “basic” factors in mobility
!

- Distance / Cost (a.k.a. laziness)
- Population density (a.k.a. opportunities)

(We look for causality, not correlation)
15
Macro/Meso level:
(urban/regional/national)

We need a general model for mobility networks…

Taking inspiration from Statistical Mechanics
and Network Theory, one can define flexible
null models.

16
We need a null model for the
data...
Procedure:
1. Fix some hypothesis
“The population leaving or entering each cell is given”
!
(quite a lot of maths….)*

2. Generate predictions
“How do the flows organize?”
!

3. Compare
Data vs Prediction
Sagarra, O. et altr. Phys. Rev. E 88, 062806 (2013)

17
Roadmap
Raw data
Experiments, Databases...

Prediction
(Product)

Data treatment tools

Statistical Validation
Hypothesis...
Modelling

(We are here)

Clean data
Null Model predictions

Data features
Visualizations
18
What’s the goal of all this?
Understand what drives human mobility
Discriminate important factors from negligible ones
(population density, distance, cost...)
Create tools to study data in an unbiased manner

19
osagarra@ub.edu
@usagarra

Thanks for your attention...

20

More Related Content

Similar to Networks, Big Data and Statistical Physics: A killing combination

Short and Long of Data Driven Innovation
Short and Long of Data Driven InnovationShort and Long of Data Driven Innovation
Short and Long of Data Driven Innovation
David De Roure
 
Critical Network Mapping, Burak Arikan talk at Eyeo2014, Minneapolis
Critical Network Mapping, Burak Arikan talk at Eyeo2014, MinneapolisCritical Network Mapping, Burak Arikan talk at Eyeo2014, Minneapolis
Critical Network Mapping, Burak Arikan talk at Eyeo2014, Minneapolis
Burak Arikan
 
AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...
AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...
AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...
Azamat Abdoullaev
 
Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...
Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...
Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...
Amit Sheth
 
Smart Data - How you and I will exploit Big Data for personalized digital hea...
Smart Data - How you and I will exploit Big Data for personalized digital hea...Smart Data - How you and I will exploit Big Data for personalized digital hea...
Smart Data - How you and I will exploit Big Data for personalized digital hea...
Amit Sheth
 
Reality Mining
Reality MiningReality Mining
Reality Mining
CI&T
 
15 Network Visualization and Communities
15 Network Visualization and Communities15 Network Visualization and Communities
15 Network Visualization and Communities
Duke Network Analysis Center
 
Artificial Intelligence for Biology
Artificial Intelligence for BiologyArtificial Intelligence for Biology
Artificial Intelligence for Biology
arannadelwar361
 
Cognitive Computing for Tacit Knowledge1
Cognitive Computing for Tacit Knowledge1Cognitive Computing for Tacit Knowledge1
Cognitive Computing for Tacit Knowledge1Lucia Gradinariu
 
Deep Neural Networks for Machine Learning
Deep Neural Networks for Machine LearningDeep Neural Networks for Machine Learning
Deep Neural Networks for Machine Learning
Justin Beirold
 
Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...
Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...
Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...
José Nafría
 
07 Network Visualization
07 Network Visualization07 Network Visualization
07 Network Visualization
Duke Network Analysis Center
 
Artificial intelligence uses in productive systems and impacts on the world...
Artificial intelligence   uses in productive systems and impacts on the world...Artificial intelligence   uses in productive systems and impacts on the world...
Artificial intelligence uses in productive systems and impacts on the world...
Fernando Alcoforado
 
AI Presentation 1
AI Presentation 1AI Presentation 1
AI Presentation 1
Mustafa Kuğu
 
DN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen Hamilton
DN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen HamiltonDN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen Hamilton
DN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen Hamilton
Dataconomy Media
 
Semantic Sensor Networks and Linked Stream Data
Semantic Sensor Networks and Linked Stream DataSemantic Sensor Networks and Linked Stream Data
Semantic Sensor Networks and Linked Stream Data
Oscar Corcho
 
New Data `New Computation
New Data `New ComputationNew Data `New Computation
New Data `New Computation
David De Roure
 
ALT Ethical AI summit, HB keynote, Dec 2023
ALT Ethical AI summit, HB keynote, Dec 2023ALT Ethical AI summit, HB keynote, Dec 2023
ALT Ethical AI summit, HB keynote, Dec 2023
Helen Beetham
 
Dark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common Sense
Dark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common SenseDark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common Sense
Dark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common Sense
Boston Global Forum
 

Similar to Networks, Big Data and Statistical Physics: A killing combination (20)

Short and Long of Data Driven Innovation
Short and Long of Data Driven InnovationShort and Long of Data Driven Innovation
Short and Long of Data Driven Innovation
 
Critical Network Mapping, Burak Arikan talk at Eyeo2014, Minneapolis
Critical Network Mapping, Burak Arikan talk at Eyeo2014, MinneapolisCritical Network Mapping, Burak Arikan talk at Eyeo2014, Minneapolis
Critical Network Mapping, Burak Arikan talk at Eyeo2014, Minneapolis
 
AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...
AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...
AI WORLD: I-World: EIS Global Innovation Platform: BIG Knowledge World vs. BI...
 
Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...
Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...
Computing for Human Experience: Sensors, Perception, Semantics, Social Comput...
 
Smart Data - How you and I will exploit Big Data for personalized digital hea...
Smart Data - How you and I will exploit Big Data for personalized digital hea...Smart Data - How you and I will exploit Big Data for personalized digital hea...
Smart Data - How you and I will exploit Big Data for personalized digital hea...
 
Reality Mining
Reality MiningReality Mining
Reality Mining
 
15 Network Visualization and Communities
15 Network Visualization and Communities15 Network Visualization and Communities
15 Network Visualization and Communities
 
Artificial Intelligence for Biology
Artificial Intelligence for BiologyArtificial Intelligence for Biology
Artificial Intelligence for Biology
 
Cognitive Computing for Tacit Knowledge1
Cognitive Computing for Tacit Knowledge1Cognitive Computing for Tacit Knowledge1
Cognitive Computing for Tacit Knowledge1
 
Deep Neural Networks for Machine Learning
Deep Neural Networks for Machine LearningDeep Neural Networks for Machine Learning
Deep Neural Networks for Machine Learning
 
Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...
Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...
Gordana Dodig-Crnkovic: Participating and Anticipating. Actors and Agents Net...
 
07 Network Visualization
07 Network Visualization07 Network Visualization
07 Network Visualization
 
Artificial intelligence uses in productive systems and impacts on the world...
Artificial intelligence   uses in productive systems and impacts on the world...Artificial intelligence   uses in productive systems and impacts on the world...
Artificial intelligence uses in productive systems and impacts on the world...
 
AI Presentation 1
AI Presentation 1AI Presentation 1
AI Presentation 1
 
DN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen Hamilton
DN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen HamiltonDN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen Hamilton
DN2017 | From Big Data to Smart Data | Kirk Borne | Booz Allen Hamilton
 
Semantic Sensor Networks and Linked Stream Data
Semantic Sensor Networks and Linked Stream DataSemantic Sensor Networks and Linked Stream Data
Semantic Sensor Networks and Linked Stream Data
 
50120130406043
5012013040604350120130406043
50120130406043
 
New Data `New Computation
New Data `New ComputationNew Data `New Computation
New Data `New Computation
 
ALT Ethical AI summit, HB keynote, Dec 2023
ALT Ethical AI summit, HB keynote, Dec 2023ALT Ethical AI summit, HB keynote, Dec 2023
ALT Ethical AI summit, HB keynote, Dec 2023
 
Dark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common Sense
Dark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common SenseDark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common Sense
Dark, Beyond Deep: A Paradigm Shift to Cognitive AI with Humanlike Common Sense
 

Recently uploaded

Acetabularia Information For Class 9 .docx
Acetabularia Information For Class 9  .docxAcetabularia Information For Class 9  .docx
Acetabularia Information For Class 9 .docx
vaibhavrinwa19
 
Guidance_and_Counselling.pdf B.Ed. 4th Semester
Guidance_and_Counselling.pdf B.Ed. 4th SemesterGuidance_and_Counselling.pdf B.Ed. 4th Semester
Guidance_and_Counselling.pdf B.Ed. 4th Semester
Atul Kumar Singh
 
Digital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and ResearchDigital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and Research
Vikramjit Singh
 
Honest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptxHonest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptx
timhan337
 
The French Revolution Class 9 Study Material pdf free download
The French Revolution Class 9 Study Material pdf free downloadThe French Revolution Class 9 Study Material pdf free download
The French Revolution Class 9 Study Material pdf free download
Vivekanand Anglo Vedic Academy
 
Digital Artifact 2 - Investigating Pavilion Designs
Digital Artifact 2 - Investigating Pavilion DesignsDigital Artifact 2 - Investigating Pavilion Designs
Digital Artifact 2 - Investigating Pavilion Designs
chanes7
 
The basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptxThe basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptx
heathfieldcps1
 
CACJapan - GROUP Presentation 1- Wk 4.pdf
CACJapan - GROUP Presentation 1- Wk 4.pdfCACJapan - GROUP Presentation 1- Wk 4.pdf
CACJapan - GROUP Presentation 1- Wk 4.pdf
camakaiclarkmusic
 
Group Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana BuscigliopptxGroup Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana Buscigliopptx
ArianaBusciglio
 
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
Nguyen Thanh Tu Collection
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
Sandy Millin
 
How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17
Celine George
 
S1-Introduction-Biopesticides in ICM.pptx
S1-Introduction-Biopesticides in ICM.pptxS1-Introduction-Biopesticides in ICM.pptx
S1-Introduction-Biopesticides in ICM.pptx
tarandeep35
 
Lapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdfLapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdf
Jean Carlos Nunes Paixão
 
Operation Blue Star - Saka Neela Tara
Operation Blue Star   -  Saka Neela TaraOperation Blue Star   -  Saka Neela Tara
Operation Blue Star - Saka Neela Tara
Balvir Singh
 
Best Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDABest Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDA
deeptiverma2406
 
Multithreading_in_C++ - std::thread, race condition
Multithreading_in_C++ - std::thread, race conditionMultithreading_in_C++ - std::thread, race condition
Multithreading_in_C++ - std::thread, race condition
Mohammed Sikander
 
Home assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdfHome assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdf
Tamralipta Mahavidyalaya
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
Pavel ( NSTU)
 
Francesca Gottschalk - How can education support child empowerment.pptx
Francesca Gottschalk - How can education support child empowerment.pptxFrancesca Gottschalk - How can education support child empowerment.pptx
Francesca Gottschalk - How can education support child empowerment.pptx
EduSkills OECD
 

Recently uploaded (20)

Acetabularia Information For Class 9 .docx
Acetabularia Information For Class 9  .docxAcetabularia Information For Class 9  .docx
Acetabularia Information For Class 9 .docx
 
Guidance_and_Counselling.pdf B.Ed. 4th Semester
Guidance_and_Counselling.pdf B.Ed. 4th SemesterGuidance_and_Counselling.pdf B.Ed. 4th Semester
Guidance_and_Counselling.pdf B.Ed. 4th Semester
 
Digital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and ResearchDigital Tools and AI for Teaching Learning and Research
Digital Tools and AI for Teaching Learning and Research
 
Honest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptxHonest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptx
 
The French Revolution Class 9 Study Material pdf free download
The French Revolution Class 9 Study Material pdf free downloadThe French Revolution Class 9 Study Material pdf free download
The French Revolution Class 9 Study Material pdf free download
 
Digital Artifact 2 - Investigating Pavilion Designs
Digital Artifact 2 - Investigating Pavilion DesignsDigital Artifact 2 - Investigating Pavilion Designs
Digital Artifact 2 - Investigating Pavilion Designs
 
The basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptxThe basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptx
 
CACJapan - GROUP Presentation 1- Wk 4.pdf
CACJapan - GROUP Presentation 1- Wk 4.pdfCACJapan - GROUP Presentation 1- Wk 4.pdf
CACJapan - GROUP Presentation 1- Wk 4.pdf
 
Group Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana BuscigliopptxGroup Presentation 2 Economics.Ariana Buscigliopptx
Group Presentation 2 Economics.Ariana Buscigliopptx
 
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
 
How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17
 
S1-Introduction-Biopesticides in ICM.pptx
S1-Introduction-Biopesticides in ICM.pptxS1-Introduction-Biopesticides in ICM.pptx
S1-Introduction-Biopesticides in ICM.pptx
 
Lapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdfLapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdf
 
Operation Blue Star - Saka Neela Tara
Operation Blue Star   -  Saka Neela TaraOperation Blue Star   -  Saka Neela Tara
Operation Blue Star - Saka Neela Tara
 
Best Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDABest Digital Marketing Institute In NOIDA
Best Digital Marketing Institute In NOIDA
 
Multithreading_in_C++ - std::thread, race condition
Multithreading_in_C++ - std::thread, race conditionMultithreading_in_C++ - std::thread, race condition
Multithreading_in_C++ - std::thread, race condition
 
Home assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdfHome assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdf
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
 
Francesca Gottschalk - How can education support child empowerment.pptx
Francesca Gottschalk - How can education support child empowerment.pptxFrancesca Gottschalk - How can education support child empowerment.pptx
Francesca Gottschalk - How can education support child empowerment.pptx
 

Networks, Big Data and Statistical Physics: A killing combination

  • 1. Statistical Physics, Network theory & Big data An approach to human mobility Oleguer Sagarra Dept. Física Fonamental, University of Barcelona 1
  • 2. A killing combination... Statistical Physics & Big Data “New Social Sciences” 2
  • 3. Why? We want to study Human Mobility… Mobility has deep implications in many processes.. (contagion, spread of ideas...) The development of GPS/mobile phone technologies makes gathering data cheap and possible at large scale. 3
  • 4. What? (Human) Mobility is a rather complex process… Different scales (Micro/Meso/Macro) Society is heterogeneous… (Humans are not “monkeys”… in principle!) But we are physicists! So we will try to model it anyway… 4
  • 5. But we don’t need modelling… “Computers are useless, they can only give you answers…” (P. Picasso) This talk is about questions rather… “Models push the boundaries of our understanding" 5
  • 7. The data... (has problems) a) How to get it? Private companies (Social Media) Citizens 7
  • 8. Getting the data... Experiments Smartphones give lots of “sensing opportunities” Citizen science aims to involve people in data collection, sharing and processing BeePath: Experiments on human mobility http://bee-path.net (Btw: Very interesting project, but don’t have time for it today) 8
  • 9. Getting the data... Social Media b) Is it biased? (Big data can also mean big errors) 9
  • 10. Social media data Social media data is geolocalized, we can extract trajectories from it. But first, is the data representative from the population? (We want info about people, not about “some people that tweet a lot”) We can compare with the census… Analysis must be done at user level! 10
  • 11. The data... is geolocalized, and (too) big! c) Continuous vs discrete data From points to a network? (We want only the flows: From where and to where people go, “on average”) 11
  • 13. Network data (We can now apply network metrics and… data is normalized!) Sagarra, O. Master Thesis. http://upcommons.upc.edu/pfc/handle/ 2099.1/13134 13
  • 14. Now we know how to deal with the data... We want to detect “abnormal” patterns... What is chance, what is not? What is important, what is not? 14
  • 15. Modeling as a physicist… Take all trivial elements out… Keep just the “basic” factors in mobility ! - Distance / Cost (a.k.a. laziness) - Population density (a.k.a. opportunities) (We look for causality, not correlation) 15
  • 16. Macro/Meso level: (urban/regional/national) We need a general model for mobility networks… Taking inspiration from Statistical Mechanics and Network Theory, one can define flexible null models. 16
  • 17. We need a null model for the data... Procedure: 1. Fix some hypothesis “The population leaving or entering each cell is given” ! (quite a lot of maths….)* 2. Generate predictions “How do the flows organize?” ! 3. Compare Data vs Prediction Sagarra, O. et altr. Phys. Rev. E 88, 062806 (2013) 17
  • 18. Roadmap Raw data Experiments, Databases... Prediction (Product) Data treatment tools Statistical Validation Hypothesis... Modelling (We are here) Clean data Null Model predictions Data features Visualizations 18
  • 19. What’s the goal of all this? Understand what drives human mobility Discriminate important factors from negligible ones (population density, distance, cost...) Create tools to study data in an unbiased manner 19