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Social Networks and More: Harambenet 2006 1
Social Networksas a Foundationfor Computer Science
Owen Astrachan, Jeff Forbes, Susan Rodger,Casey Alt, Richard Lucic, Robert Duvallhttp://www.cs.duke.edu/csed/harambenet
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Where are we going … Questions What should our concerns be for those choosing to major in Computer Science? courses, research, jobs, …
Should we be concerned by the precipitous decline in those taking our courses or majoring or …? majors, technical students, non-technical …
What can we do to ensure the ongoing success of our academic discipline? Look inward, look to others
Social Networks and More: Harambenet 2006 3
Acknowledgements Social Networks/Broadening Participation group:
Jeff Forbes helped with this talk Casey Alt, Richard Lucic, Susan Rodger Students: Ben Spain & Dametrious Peyton
Drawn from the work of: Michael Kearns, UPenn Eytan Adar, formerly of HP Labs John Breese, David Heckerman, Microsoft Research Jonathan Herlocker, Oregon State University Thomas Hoffman, Brown University Marti Hearst, UC Berkeley Jennifer Golbeck, University of Maryland
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Social Networks and More: Harambenet 2006 5
WWDD?
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Questions
If you gotta ask, you’ll never knowLouis Armstrong: “What’s jazz?”
If you gotta ask, you ain’t got itFats Waller: “What’s rhythm?”
What questions did you ask in school
today?Arno Penzias via Isaac Isadore Rabi
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Questions and Answers
Judge a man by his questions rather than by his answers
Voltaire
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Computer Science
What is the foundation of computer science? Historically, now, in the future
What changes are here, on the horizon? From theory to practice to education
Can we relate to what and how students learn? Is every generation different, the same, …
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History and Computer Science Those who cannot remember the past are condemned to repeat it.
Don’t know much about history, don’t know much about biology, don’t know much about a science book
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Who, when?
“No stretching … is required to envision computer consoles installed in every home.
Everyone will have better access to the Library of Congress than the librarian himself now has.
Full reports on current events, whether baseball scores, the smog index in Los Angeles or the minutes of the 178th Korean Truce Commission will be available for the asking.”John, McCarthy, Information, Chapter
1, 1966
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You win some, you lose some
People will soon become discontented with the “canned” programs available; they will want to write their own. The ability to write a computer program will be as widespread as the ability to drive a car.
Not knowing how to program will be like living in a house full of servants and not speaking their language.
Many people can write simple programs after an hour or two of instruction. … Programming is far easier to learn than a foreign language or algebra.
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Then and Now
Bailey, SIGCSE 1972
It is remarkable that the majority of students can indeed handle fairly complex (Fortran) I/O by the end of the first six lessons, even though they have not actually been formally taught how to do it.
Roberts et al, SIGCSE 2006
The problem most often cited by those attempting to teach Java to novices is the lack of a simple input mechanism,
kentlew.com
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What has changed in 20 years?
Machines Characteristics and Availability
Internet Availability, IM, web, Google, …
Students Comfort with technology, Expectations
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Teaching Compsci in 1984 64K memory, 128K extended
8-bit, 1 Mhz 6502 processor
5Mb drive: $3500 UCSD Pascal: >$100 Owen's machine: $3000
$677.80 in 1984 has $1200 "purchase power" in 2003
http://eh.net/hmit/ppowerusd/
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Typical machine in 2006?
1 Gb memory 3 GHz, 32-bit chip
Cache, … 160 Gb disk Lots of free resources Good academic pricing
Under $600 (priced 6/19/06)
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The more things change…?
Assume I took your first course(s) in 1984 and understood the concepts so completely that I could still get a 100 on the final from 1984 if I took it today (e.g., I've been in a cryogenic chamber). How would I do on the 2004 final exam?
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What has changed in Physics?
"You'd get a 100 plus or minus sigma. Intro classical physics hasn't really changed that much over the last 100 years. In graduate level e.g. E&M or quantum classes I think ditto, although sigma would be bigger (and might depend more on the instructor variation than on any real variation in the material). The main difference is, I think, that your chances of GETTING 100 now would be much higher."
Rob Brown, Poohbah of Physics Instruction
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What has changed in Biology?
"The basic principles and concepts of biology haven't changed much in 20 years. What has changed relates to specific content, and in this arena the changes have been enormous. 20 years ago, we barely knew how to sequence DNA; today information of this kind has had a major impact on just about every topic in the biological sciences. Thus, some questions on an exam today would address topics that would be completely unfamiliar to a 1984 time-traveller. "
Greg Wray,
Director of Undergraduate Studies, Biology
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What has changed in Economics?
"… we now cover material that was only introduced in an advanced or intermediate course in 1984. In 1984 we spent the bulk of the time dealing with the Keynesian model and virtually no dialogue about supply side policies. Now the Keynesian stuff is a small subset of a much broader exposure to Aggregate demand and supply… Also there is more international coverage now - as opposed to 20 years ago for obvious reasons."
Lori Leachman, Director of Undergraduate Studies, Economics
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What has changed in Calculus?We have two varieties of calculus courses, the lab
courses and the traditional ... The latter two have not changed significantly in decades, and I think that a student who fared well on the 1984 exam in those courses would do well today, and vice versa.
[In the lab courses] You would ace about half the exam. The other half would be unfamiliar to you. For example, you would probably not know how to answer a problem on modeling a set of data, creating an approximation using Euler's method, interpreting derivatives in the context of applications in other fields, or giving explanations of ideas …
Lewis Blake,Supervisor of First-year Instruction
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Changes in Computer Science?
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Changing CS? Rock, Hard place
If Computer Science has changed drastically is it to keep up with fads and stylistic changes or because of fundamental changes in the discipline?
Are we leveraging the technological and intellectual resources at our disposal
If we haven’t changed, is it because of a solid bedrock of principles that endures? Or because we’re lazy, good-for-nothing, …
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What is CS? Who wants to study it? Why do they want to?
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NYTimes in 1984
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What is CS? Why study it?
Do we have Physics (Math, …) Envy? “It's hard for voice over Internet Protocol or e-commerce to compete with finding the age of the universe,” Peter Lee, CMU
Does familiarity breed contempt? What was different in 1984 than today?
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What is Computer Science?
What is the linking thread which gathers these disparate branches into a single discipline? My answer to these questions is simple --- it is the art of programming a computer.
What is the central core of the subject? What is it that distinguishes it from the separate subjects with which it is related?
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Is this Computer Science?
public static void stuff(int n){doit(n,0,1,2);
}public static void doit(int n,int f, int t, int a){ if (n == 1) move(n,f,t); else { doit(n-1,f,a,t); move(n,f,t); doit(n-1,a,t,f); }}
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Occupational Distribution of Projected S&E Job Openings 2002-2012
Natural Science
Managers
Information Technology
Engineers
Physical Scientists
Life Scientists
John Sargent, US Department of Commerce, 2004
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Annual Degrees and Job Openings in Broad S&E Fields
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Engineering Physical Sciences Computer Sciences Biological / Agricultural Sciences
PhD
Master's
Bachelor's
Projected Job Openings
John Sargent, US Department of Commerce, 2004
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US Census Bureau
Demographics: 18 - 24 year olds
White Asian/PacificIslander
Hispanic
African American
Native American
2000 66% 4% 15% 14% 1%
2010 63% 5% 17% 14% 1%
2025 55% 7% 22% 15% 1%
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Bachelor’s Degrees from Doctoral Institutions
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COHFE Amherst College, Barnard College, Brown University, Bryn Mawr College, Carleton College, Columbia University, Cornell University, Dartmouth College, Duke University, Georgetown University, Harvard University, Johns Hopkins University, Massachusetts Institute of Technology, Mount Holyoke College, Northwestern University, Oberlin College, Pomona College, Princeton University, Rice University, Smith College, Stanford University, Swarthmore College, Trinity College, University of Chicago, University of Pennsylvania, University of Rochester, Washington University in St. Louis, Wellesley College, Wesleyan University, Williams College, Yale University
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If you don’t take a course in CS, you won’t major in it.Why is the first year different from all other years?
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Who's going to College?
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Who's going to College?
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Who's going to College?
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How do we get Studentsinto the Compsci Tent?
Why is the first year different from all other years?
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Interdisciplinary minors At Duke it is difficult to double major in sciences Too many requirements, 17 courses in biology
Students are interested in credentials No business major/minor, certificate program (requires intro, capstone, six courses)
Minor requires five courses, double counting ok Three courses in CS, two in econ or biology From gene to social networks, data mining, …
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Genome Revolution Focus Course Arts in Contemporay Society, Exploring the Mind, Evolution and Humankind, 20th Century Europe, Visions of Freedom, The Genome Revolution and its Impact on Society, … Three of four courses, one writing, two others. Interdisciplinary 0.5 credit seminar P/F
Seminars, students live in same dorm 600+ out of 1600 in FOCUS course
For Genome, 80 applicants for 30 slots, 65% women In CS Genomics course 8 women, 9 men
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Simple examples Given strand of DNA, calculate CG ratio
Potential source of proteins “CGGATTATC”
Given protein “HLVWW” calculate number of different DNA strands that could code for it 64 codons, 20 amino acids
Find heaviest protein in array of proteins Given atomic mass of amino acids
Interpret ORF data from NCBI website
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Read DNA assumed to be in 5’ to 3’ orientation Use BioJava to read via http
Construct reverse complement (3’ to 5’) From CAATT produce AATTG
How big is the human genome? Runtime of algorithm O(1)
From Algorithms to Objects
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Computer Science is filled with real-world examples.Why is the first year different from all other years?
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Teaching as … English is not history
and history is not science and science is not art and art is not music, and art and music are minor subjects and English, history and science major subjects, and a subject is something you 'take' and when you have taken it, you have 'had' it, and if you have 'had' it, you are immune and need not take it again." (The Vaccination Theory of Education?)
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Back to the Future
How will we know when we get there?
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A Future for Computer Science?
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Is there a Science of Networks? From Erdos numbers to random graphs to Internet
From FOAF to Selfish Routing: apparent similarities between many human and technological systems & organization
Modeling, simulation, and hypotheses Compelling concepts
• Metaphor of viral spread• Properties of connectivity has qualitative and quantitative effects
Computer Science?
From the facebook to tomogravity How do we model networks, measure them, and
reason about them? What mathematics is necessary? Will the real-world intrude?
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Physical Networks The Internet
Vertices: Routers Edges: Physical connections
Another layer of abstraction Vertices: Autonomous systems Edges: peering agreements Both a physical and business network
Other examples US Power Grid Interdependence and August 2003 blackout
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What does the Internet look like?
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US Power Grid
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Business & Economic Networks Example: eBay bidding
vertices: eBay users links: represent bidder-seller or buyer-seller fraud detection: bidding rings
Example: corporate boards vertices: corporations links: between companies that share a board
member Example: corporate partnerships
vertices: corporations links: represent formal joint ventures
Example: goods exchange networks vertices: buyers and sellers of commodities links: represent “permissible” transactions
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Content Networks
Example: Document similarity Vertices: documents on web Edges: Weights defined by similarity See TouchGraph GoogleBrowser
Conceptual network: thesaurus Vertices: words Edges: synonym relationships
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Enron
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Social networks Example: Acquaintanceship networks
vertices: people in the world links: have met in person and know last names hard to measure
Example: scientific collaboration vertices: math and computer science researchers links: between coauthors on a published paper Erdos numbers : distance to Paul Erdos Erdos was definitely a hub or connector; had 507
coauthors How do we navigate in such networks?
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Acquaintanceship & more
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Network Models (Barabasi) Differences between Internet, Kazaa, Chord Building, modeling, predicting
Static networks, Dynamic networks Modeling and simulation
Random and Scale-free Implications?
Structure and Evolution Modeling via Touchgraph
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Web-based social networkshttp://trust.mindswap.org
Myspace 73,000,000 Passion.com 23,000,000 Friendster 21,000,000 Black Planet 17,000,000 Facebook 8,000,000
Who’s using these, what are they doing, how often are they doing it, why are they doing it?
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Golbeck’s Criteria
Accessible over the web via a browser
Users explicitly state relationships Not mined or inferred
Relationships visible and browsable by others Reasons?
Support for users to make connections Simple HTML pages don’t suffice
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CSE 112, Networked Life (UPenn)
Find the person in Facebook with the most friends Document your process
Find the person with the fewest friends What does this mean?
Search for profiles with some phrase that yields 30-100 matches Graph degrees/friends, what is distribution?
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CompSci 1: Overview CS0
Audioscrobbler and last.fm Collaborative filtering What is a neighbor? What is the network?
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What can we do with real data? How do we find a graph’s diameter?
This is the maximal shortest path between any pair of vertices
Can we do this in big graphs?
What is the center of a graph? From rumor mills to terrorists How is this related to diameter?
Demo GUESS (as augmented at Duke) IM data, Audioscrobbler data
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Collaborative Filtering Goal: predict the utility of an item to a
particular user based on a database of user profiles User profiles contain user preference information
Preference may be explicit or implicit• Explicit means that a user votes explicitly on some scale
• Implicit means that the system interprets user behavior or selections to impute a vote
Problems Missing data: voting is neither complete nor uniform
Preferences may change over time Interface issues
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My recommendations at Amazon
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And again…
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Finally, …
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Whose recommendations?
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And again…
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Alan Kay
"Simple things should be simple. Complex things should be possible".
"The best way to predict the future is to invent it"