• NSF Expeditions.  For ambitious projects involving a large team, funded at a level up to $2m/year for up to 5 years. Princeton’s CCI is one such expedition.  Preliminary Proposal Deadline: March 10.
• Women in Theory workshop being held at Princeton June 23-27, 2012. Intended for graduate and undergraduate students in the area of theory of computer science.   Application Deadline: February 29.

• Postdoc at KTH Royal Institute of Technology (deadline Jan 31)
• Postdoc at Cornell at the interface of networks, computing, and economics (deadline Jan 30)
• Simons postdoc at Carnegie Mellon (deadline Jan 31)
• Postdoc at LIAFA (Paris) (deadline Feb 1)
• Theory Postdoc at EPFL and Faculty positions at EPFL (no deadline stated)
• Postdoc in Theory/Practice of Differential Privacy at UPenn (no deadline stated)
• Postdoc in Cryptography at Tel-Aviv University (no deadline stated)
• Faculty positions at Northeastern University, Boston. (no deadline stated)
• Tenure-track Faculty Position at Purdue (Krannert School of Management) (no deadline stated)

Check http://intractability.princeton.edu/jobs/ for further updates.

2. IAS summer school in Computation and Biology, July 9-20, 2012, will explore topics at the interface of theoretical computer science, statistical physics and quantitative biology.  Organizers are Bernard Chazelle, David Huse, and Stanislas Leibler. Information about application procedures and a program schedule can be found on the website: www.ias.edu/pitp.  The program is intended for both PhD students and postdocs.  Application deadline: March 1, 2012. Here is a publicity poster.

• Quantum Science and Technology
• Mathematics (listing algorithms, geometric and topological methods, combinatorics, and graph theory and network analysis, among others)
• Computational and Quantitative Social, Decision, and Behavioral Sciences.

Submission deadline is 4pm ET January 19, 2012.

See http://www.darpa.mil/Opportunities/Universities/Young_Faculty.aspx and the grants.gov site for more information.

This is the blog for the SIGACT Committee for the Advancement of Theoretical Computer Science (CATCS).  The aims of this blog and site are to:

1. Inform the TCS community about funding opportunities that arise, as well as discuss tips, suggestions, and experiences related to funding and funding agencies.
2. Provide information (nuggets, slides, descriptions, surveys) that members of the TCS community can use to help in explaining the excitement of TCS to the broader public.
3. Enlist the help of the TCS community for matters vital to the community as a whole, for instance in identifying candidates for NSF program directors, etc.

This site is based on the theorymatters wiki initially created by Sanjeev Arora, Boaz Barak, and Luca Trevisan in 2005, and subsequently transferred to the oversight of the CATCS and maintained substantially by Salil Vadhan.  The porting of the wiki to a blog was done by Boaz Barak, Moses Charikar, and Luca Trevisan (many thanks to Boaz, Moses, and Luca for doing this!).

We hope you find this blog and site useful.  Feel free to contact committee members directly with questions or suggestions.

-Avrim Blum (CATCS chair)

• Identify broad research themes within theoretical computer science (TCS) that have potential for a major impact in the future, &
• Distill these research directions into compelling “nuggets” that can quickly convey their importance to a layperson.

The main purpose of these nuggets are to help the CCC and others argue for the importance of computing research, and TCS in particular, to a variety of audiences. Some may also inspire the development of new centers or large-scale research activities (as might be funded by the new NSF Expeditions in Computing program), and others may be broadened and inspire entirely new programs (similarly to the way the NSF CDI program was inspired by 06-07 workshops on CS as a Lens on the Sciences).

• Organizers: Bernard Chazelle, Anna Karlin, Richard Ladner, Dick Lipton, and Salil Vadhan
• Vision Nuggets.
• Workshop Program.
• Confirmed Participants.
• Logistics.
• Final Report for CCC.

If you have any questions, please email tcsvisions AT gmail.com.

1. Low grant sizes in TCS, and too few of them. Grant sizes are now $70K/year.  A more viable grant size (paying for say summer salary+one student + computer/travel) will truly raise the effectiveness of researchers, allow grad training to continue, and lower various overheads for both researchers and NSF/CISE.  Researchers would write fewer proposals.
   In recent years there has also been a severe problem with very low numbers of funded proposals. In 2005 this was  ameliorated a bit since CISE made a special effort to raise the funding rate in TCS this year (both by increasing the TCS program budget and by reducing grant sizes). But the underlying fact is that the total budget of the TCS program is essentially unchanged since 1989 (which means it has greatly decreased in real dollars).
2. TCS’s position in the CISE hierarchy is too low which causes CISE leadership to miss its importance. CISE’s view of TCS (a sibling of numerical and symbolic computation, information theory, geometric computation, etc. in the TF cluster) seems out of accord with the view in most research  departments (viz., TCS as a major subdiscipline of CS on a par with AI, systems, software systems, etc.). Note that both AI and Networking and Systems are two levels higher than TCS in the CISE hierarchy.One recent statistic to support this: this spring six of the top 10 CS depts —Stanford, CMU, Cornell, UW, U. Wisc (Madison), UIUC– made offers to six different junior TCS people (five of which were accepted). This may greatly exceed the tally for any other leaf of the CISE tree, or the combined tally for the rest of the Theoretical Foundations Cluster.
3. Apart from the dedicated TCS program, few NSF programs support long-term, basic research. There is a pressing need for new NSF initiatives that support long-term, basic research  and which welcome TCS proposals. The TCS community also needs to be proactive too. Whenever NSF proposes new crosscutting initiatives –e.g., the new networking initiative– the TCS community needs to help delineate ways in which it can contribute.

Visit by Karp and Lipton to NSF (Sept 2005)

In early September, Richard Karp (committee chair) and Richard Lipton  visited Washington DC and met with top CISE officials, CRA staff members, and  two congressional staffers. The general tenor of the meetings was supportive and constructive. Karp gave a 1-hour talk at NSF about “Key Challenges in  Theoretical CS” that surveyed the vast spectrum of past TCS innovations and outlined some key challenges for the future. The talk was very well-attended and well-received. Slides appear here. 

A few concrete action items were formulated as a result of the meetings.

1. The TCS community will give a writeup to CCF director Mike Foster suggesting the proper budget for TCS together with a detailed justification (including recent breakthroughs, future challenges etc.).  Foster will use it in his budget planning in future years. (But no concrete promises were made.) The details of this document may be discussed at evening meetings in the upcoming FOCS and STOC conferences.
2. The TCS community will propose and help develop a new NSF program devoted to “Theory of Networked Computation”  (the name is provisional) . This could be loosely linked to the the new GENI initiative in networking research  at  CISE. The exact structure and research goals for this proposed ToNC program would  be worked out over a couple of NSF-funded workshops in Spring 2006, and a detailed proposal will be ready in time for the budget process in Fall 2006. The SIGACT committee will arrange the workshops and write a SGER proposal to get funding for them. It is anticipated that “Theory of Networked Computation” will be defined fairly broadly.
3. The SIGACT committee will actively work with CISE  officials to  get  TCS  researchers into  advisory positions at CISE. It will also help recruit TCS candidates for  positions that open up at NSF. Currently, Mike Foster is looking for two program officers in the Theoretical Foundations cluster, and encourages TCS researchers to apply.It is very important to get more TCS researchers appointed as program officers. As part of its effort to promote “riskier” long term research, and to make up for DARPA’s departure from funding academic computer science, NSF  plans to  dedicate as much of a third of its funds to research projects chosen by program officers. Thus program officers will play an important role in setting research priorities (as they used to at DARPA).
4. CISE AD Peter Freeman would like to encourage the TCS community to publish a pamphlet through CRA summarizing what TCS is,  what its fundamental problems are, and how it contributes to the nation’s science and technology. (NSF is willing to underwrite the cost.) Other scientific disciplines do such things to maintain a higher profile and thus work themselves into the nation’s funding priorities. A few other subareas of CS have done this successfully as well (see, e.g. this pamphlet).

As computer science enters an era of new challenges and multidisciplinary opportunities, there is a pressing need for new approaches, new conceptual models, and unconventional ideas. Theoretical computer science (TCS) has a proven track record in providing all of these.  TCS innovations such as analysis of algorithms, NP-completeness, complexity-based cryptography, use of probabilistic choices in algorithms, etc., are mainstays of CS research and education and one result is the growing popularity of quantitative reasoning and formal models in all of CS. In the past decade, TCS has invented new sub-disciplines (quantum computing), contributed new paradigms for emerging areas (web-search, internet content distribution, data-mining, computational biology etc.), and made important breakthroughs in a continuing study of intrinsic complexity, NP-completeness, randomness, efficient algorithms, networks, etc. Its long-term focus is at the root of its high impact –scientific, conceptual— and this has benefited the strategic national interest. Finally, TCS has also had considerable commercial impact: several IT and Biotech companies –Google, Amazon, Celera Genomics, Akamai, Verity, Digital Fountain, etc.—rely crucially on good algorithms originating from TCS. In many cases their chief scientists were also TCS researchers (at Amazon, the title is “Chief Algorithms Officer”).

Looking ahead into the 21^st century, security and reliability will be as important in CS as performance was in the 20^th, and TCS is poised to do for these issues what it did for cryptography and probabilistic algorithms in the 20^th century. Similarly, just as TCS used its unique computational perspective to forge connections with physics (quantum computing) and biology (computational biology) in the late 20^th century, it will do the same with economics (a computational perspective of economics, game theory, mechanism design, learning, etc., currently being developed may impact e-commerce) and neuroscience (specifically, understanding the brain). Beyond its direct applicability, computing is one of the key new conceptual paradigms of modern science. But despite TCS’s stunning success stories (some of them told below), computing as a scientific concept is still mostly not understood. TCS is not unlike pre-Einstein physics: a growing and useful body of knowledge with a revolution coming ahead. TCS was largely  invented in the US and it should be considered a national priority.

This document suggests that TCS’s research agenda for the 21st century is vastly underfunded at NSF/CISE.  The budget dedicated to TCS has remained almost stationary for a long time—it was $6.4M  in 1989 and was $5.1M in 2004. (It appears that in 2005 it will rise to $7.2M.) Meanwhile, CISE’s budget tripled from 1990 to 2005. Though TCS’s importance has been well-recognized within CS (TCS work won 5 out of 15 Turing awards and 9 out of 19 ACM Dissertation awards since 1990; TCS researchers constitute at least 10% of CS faculty at the top 25 CS depts) the same does not appear to be true at CISE, which devotes only around 1% of its budget to TCS. Grant sizes have remained almost unchanged for two decades.

Though past applications of TCS are well appreciated at NSF (e.g., computational genomics and quantum computing are now funded out of a special program, and total NSF funding for quantum computing exceeds $16M/yr) there appears to be an under-appreciation of the danger that such exciting applications will stop in the future unless the long-term TCS agenda is also pursued. The dominant application-driven funding model will hamper future TCS breakthroughs: it is worth noting that the breakthroughs from 1990-1995 (including quantum computing, PCPs) were unanticipated in 1989, and those from the 1995-2000 period (including web search, internet content distribution) were equally unpredicted in 1994.

Finally, much of TCS’s impact was achieved by training a small, flexible research force in its vast body of previous work and imbuing them with TCS’s holistic bent. This well-trained workforce allowed CS to respond to various challenges in the 1990s and also pushed it into new opportunities. It is unclear how the current funding model can allow the continued training of such a TCS workforce for the future. These and related issues are discussed in Section 3.
Finally, we note that recent CRA surveys  show an alarming disinterest in computer science among the young, who are increasingly drawn to other sciences. One suggested solution by CMU dean Peter Lee is to emphasize the “science” aspect of computer science in education. TCS can play an important role here, as will be clear from the examples of TCS work in the rest of the document.
To provide a basis for the discussion of the shortcomings of current TCS funding, Section 2 surveys the history of TCS’s varied impacts, especially those from the past decade.

CHIEF RECOMMENDATION: NSF/CISE should revitalize its research and training program in TCS with a budget of $18M per year (3% of CISE budget), which could support roughly 100 researchers with grants of $125K/yr/PI on average (summer salary + 1 student +  travel/computer expenses), a postdoc program, and a CAREER program.  Such a move would vastly benefit 21^st century science and the training of the IT workforce. (See Section 4.) This budget increase could come out of funds that will become available from the expiration of the ITR program (as estimated $200M).

 1) THE TCS AGENDA FOR THE 21^st CENTURY

TCS is a multidisciplinary field that takes a holistic view of much of computer science and makes connections to many outside disciplines. A broad overview of TCS research appears in a 50-page document “Challenges for Theoretical Computer Science“ available from www.sigact.acm.org . As mentioned, it is difficult to predict TCS breakthroughs, so one cannot predict TCS’s impacts in 2006-2016. Nevertheless, some plausible examples are sketched below.

The problem of handling large data sets is already at the forefront of 21^st century needs for national security, market intelligence, health care, and cyber-infrastructure for scientific research, and it has become customary to acknowledge that “better algorithms” will play a decisive role. (Pioneering computer architect John Cocke predicted this almost two decades ago in his Turing award lecture.) But it would be a mistake to think of “better algorithms” simply as a faster implementation of a known method – such advances will predictably occur, and TCS will of course play a role. The harder problem is to invent new algorithmic frameworks and mathematical analyses to tame the data deluge. Here TCS will be crucial. In the past few years, link analysis for web search, data stream analysis, and auction design for keywords have been areas with significant impact from TCS, whereby one or more publications in TCS conferences and/or from TCS researchers gave rise to a groundswell of research and subsequent applications. Many prominent researchers in the web research community are from TCS. (Note: the claim is not that TCS is the only contributor, but that TCS often helped focus attention on core issues.) Similarly, recent TCS research directions insublinear algorithms and streaming algorithms also look very promising: Here, the spotlight is on the data, which is huge in size and dimensionality and often comes attached with uncertainty and varying costs. It must be emphasized that these contributions are merely TCS’s rapid response to a new challenge; what more could be achieved if a sustained and deeper study were funded?

Much of TCS’s scientific and conceptual impact is the direct result of its computational perspective (one of the major scientific insights of the past 50 years), which views many natural and man-made environments as a collection of computationally limited agents interacting with each other. TCS’s discoveries spring from it, whether they are in the context of age-old endeavors such as cryptography (new insight: “the adversary is computationally limited”), or of new ones such as the effort to understand computational complexity, quantum computation, or network phenomena (Web, brain, biological systems, etc.).

In the 21^st century, TCS plans to employ this computational perspective to forge a new kind of economics. It is engaged in an ongoing effort to rework much of economics, game theory, mechanism design, etc., using the idea of computationally limited players (an ambitious extension of the bounded rationality idea in economics).  Similarly, the ability to reason formally about previously nebulous concepts such as trust and privacy —visited earlier by TCS in context of cryptography—is fundamental to emerging eBusiness models. For instance, economists have quantified the premium commanded by a reliable seller at an auction site such as eBay. How does this relate mathematically to the propagation of trust through members of an online community? What new forms of auctions can arise, and how to design mechanisms by which individuals in a community are motivated to align with the collective good? These are some of the critical questions from computational economics under examination by the TCS community. It is conceivable all the above developments could impact e-commerce in future the same way cryptography impacted computer security. It could also impact many other areas.  For instance, TCS work on viral propagation and influence networks is having unanticipated links to current research in protein functional annotation.

Similarly, TCS will likely develop a connection to neuroscience as it did to genomics in the 1990s. More than one researcher has suggested that an understanding of the brain will arise from a holistic approach marrying neuroscience work with insights from TCS’s vast conceptual framework of networks, algorithms, efficient storage and manipulation of information. Valiant has suggested a computational view of the neuron network in the brain using random graphs. The hope is that the vastly complicated picture of the brain could be understood via a process of reverse engineering: how would we implement algorithms for cognition tasks on such unreliable, simple networks? It is conceivable that the space of feasible algorithms is fairly small. Such theoretical work will need to proceed hand in hand with experimental neuroscience.

System security and reliability will be as important to CS in the 21^st century as performance was in the 20^th. TCS may provide the kind of integrative, long-term study— combining examination of intrinsic complexity and invention of new theoretical concepts rather than quick application of known techniques—of these issues in the same way that the field did so effectively for cryptography and probabilistic computation in the 1980s-90s. In those celebrated developments, there was a thrilling interplay of practical issues informing the theoretical breakthroughs, with in turn the theoretical breakthroughs leading to practical applications. TCS’s 21^st century study of security and reliability could conceivably combine traditional strengths such as cryptography and program verification, recent developments concerning reliable encoding and verification of information, and its sophisticated analytic understanding of networks and protocols. It has been suggested that security of very large systems and networks may ultimately be designed by analogy to biological systems (which are also based upon large numbers of extremely unreliable elements) and here again TCS may contribute crucial insights.

Another future impact might come from ongoing efforts in TCS to overcome computational intractability in many situations via some notion of approximation (competitive analysis in many online settings, approximation for NP-hard problems, approximate data representation in geometric problems, etc.). This area is beginning to have practical and conceptual impact and important connections have also emerged to classical questions studied in mathematics.

The area of probabilistically checkable proofs (PCPs) was a big surprise when invented in the early ‘90s and has continued to yield a steady stream of breakthroughs. The underlying ideas of efficient representation and checking of information seem powerful and very counterintuitive and will surely lead to other breakthroughs, including important applications.

The study of intrinsic complexity has developed startling connection with an ongoing study of derandomization. The latter was originally motivated in the 1980s by the poor quality of real-life random number generators but led to many theoretical advances such as the 2002 breakthrough result on deterministic primality testing (which made the front page of the New York Times) as well as progress in data management and hashing (which had great commercial impact). Two years ago it was realized, to one’s great surprise, that further progress inderandomization may hold the key to complexity lower bounds (the holy grail of TCS ever since the P versus NP question was formulated).

2) TCS’S DIVERSE IMPACT AND WHAT IT SAYS ABOUT THE FIELD

This section briefly describes TCS’s varied impacts in the recent past. These may be the most (or only) reliable way to judge its future impact since TCS breakthroughs are usually unanticipated. They also illustrate TCS’s interconnected, nature and its “unexpected connections.”
Commercial impact: Increasingly, commercially successful (and paradigm-changing) computational technologies arise from good scientific ideas, especially TCS ideas—the RSA encryption scheme  that underlies much of the e-commerce infrastructure; the Hubs and Authorities algorithm (1999), which is a new tool of information retrieval and web search and influenced several search engines; the Consistent Hashing algorithm (1997) used by Akamai Technologies in the past 5 years to provide great speedups in internet content distribution. It is clear why this happened. As CS focused on manipulation, analysis, and search of large data sets, the need for faster algorithms as well as new modes of design and analysis became apparent. TCS is well-poised to provide all of these. Recognizing this, IT and biotech companies –Google, Amazon, Celera Genomics, Akamai, Yahoo, Verity,  Digital Fountain,etc.–hired TCS researchers as chief scientists.

Impact on other scientific disciplines: The impact of CS on science also traces in no small part to TCS.  In the 1990s, a small group of TCS researchers, acting on a suggestion from physicists such as Feynman and Deutsch, invented the quantum model of computation. This invention, followed in short order by Peter Shor’s breakthrough discovery of an algorithm for integer factoring, helped revitalize a good chunk of quantum physics, and is today considered an important example of multidisciplinary science. Physics Nobel laureate David Gross lists a better understanding of quantum computation as one of the 25 challenges for 21st century physics. Federal funding agencies are actively supporting efforts to find a practical implementation of this model.
In genomics, a group of TCS researchers in the 1990s helped invent a body of algorithmic techniques and models —now part of computational genomics–that allowed biologists to overcome errors in sequencing data. These sped up the historic project (a collaboration between government, industry, and academia) for sequencing the human genome. It is clear that computation-inspired models will continue to be crucial to molecular biology and neuroscience.
In mathematics and operations research, ideas such as NP-completeness, polynomial interior point methods, and number-theoretic cryptography introduced an entire new perspective and a set of research problems to these older fields. The P versus NP problem is on a list of six outstanding open problems for 21^st century mathematics. The Clay Math Institute, which maintains this list, honored a TCS breakthrough on primality testing in 2002 with a special award. In the late 1990s, the Institute for Advanced Study — the former home of Einstein,Goedel, and von Neumann– started a research program in TCS.

Conceptual impact: The above-mentioned impacts are not a sequence of lucky coincidences, but a direct result of one of the major scientific insights of the past 50 years: Thecomputational perspective, which is the essence of TCS, views many natural and man-made environments as a collection of computationally limited agents interacting with each other. Another far-reaching idea popularized by TCS (only 30 years ago!) is the use of randomness in algorithms and computation. Initially used as a simple algorithmic tool, as in network routing (randomized routers), it also led to new ways of looking at computer security (the definition of “security” of algorithms and protocols), artificial intelligence (PAC Learning, Boosting), and data management (hashing, internet content distribution).

The conceptual impact of such TCS innovations is at least as significant as its commercial one. Boosting–combining weak heuristics into a powerful learning algorithm—has been a pillar of AI and data mining since 1996: a recent text in information retrieval calls it the “the best off-the-shelf classifier in the world.” This hints at its vast practical impact, but one should realize that even the idea of boosting was completely counterintuitive to practitioners, let alone the fact that it can be practical. (This counterintuitive idea, surprisingly, came out of theoretical work in cryptography and PAC learning.) Similarly, Kleinberg’s Hubs and Authorities work (1999) was important not only as an enabler of a new technology (web search), but also as a new way of thinking about the web. It is one of three most cited papers in web research; the other two being papers by Tim Berners-Lee et al., and Google founders Brin and Page.

Creation of a coherent, multidisciplinary science. TCS’s status as an academic sub-discipline of CS —analogous to graphics, networks, scientific computation, AI, etc.— often obscures the fact that  TCS by itself is a coherent, multidisciplinary science that takes a holistic view of many areas of CS (including all the ones just named), and contributes to them. Though its inquiry spans a broad spectrum from abstract to concrete, all TCS research shares a common perspective and set of techniques. Like any healthy science, its theory is of inherent interest, yet also leads to important applications. In turn, practical issues inform its greatest theoretical breakthroughs.

One good example of this interplay is the following sequence of developments over two decades. Starting in the late 1970s, computational complexity theory, fresh from its NP-completeness success, took on the practical issues of cryptography and random number generation and transformed them —along the way inventing a computation-based framework of information, privacy, knowledge, etc. Cryptographic motivations then introduced new ideas into complexity theory, namely interactive proofs (1985), which in the 1990s led toprobabilistically checkable proofs (PCPs) and an important extension of the theory of NP-completeness— the demonstration that computing approximate solutions to many NP-hard problems is itself NP-hard. This work continued for a decade and negatively answered questions long asked by practitioners. Practical offshoots of the theoretical PCP work in late 1990s were applications in information theory (a practical algorithm for list decoding of error-correcting codes; see Appendix A) and cryptography.

Also, theoretical work often fertilizes the field with new techniques that later allow it to respond to new issues. (This is not surprising, because ultimately the theoretical work also deals with issues of efficiency, information management and representation, etc.)  Recent practical algorithmic impact mentioned above came out of this body of techniques.

3) CURRENT STATE OF NSF FUNDING FOR TCS

General note: From now on, budgets will be discussed in terms of number of regular grants they can support, which cover PI’s summer salary + 1 Ph.D. student + travel and computer expenses. Depending on the PI’s seniority level and home institution, a regular grant ranges from $115K/yr to $150K/yr and we use an average of $125K/yr. This is also the number used in new NSF programs such as the Emerging Models cluster. (Currently, TCS grants are far smaller.) 

The model of single-PI grants (“many small bets” and  occasional “medium bets” consisting of grants that pay for two PhD students) is reasonable for TCS because (a) the full impact of individual projects is harder to predict (b) TCS researchers often set up collaborations anyway.

There are two modes of funding TCS work at NSF today. First, like all other CS researchers, TCS researchers can apply to application-area programs (sometimes also called priority areas).  Second, they can apply to a dedicated TCS program whose budget in 2005 will be $7.2M (not much more than the budget of $6.4M in 1989). Since this program is now so tiny, one must carefully weigh the pros and cons of funding TCS work from other application-area programs.

Pros:
The application-driven funding model helps TCS researchers realize the practical impact of their ideas, and put together large projects to serve the nation’s immediate priorities. An example is an ongoing large ITR project (a collaboration among TCS and non-TCS researchers; budget $2.5M/yr) that will, among other things, develop practical implementations of far-reaching TCS work from the 1980s by Yao and others on privacy-preserving multiparty computations. This will impact data mining and database management in the next few years and is a good example of the sort of sophisticated “technology transfer” that is crucial for the nation’s technological and security infrastructure. This kind of work should continue to be encouraged.

Cons:

(A) Inability to anticipate issues that may become priorities in more than 5 years. The above example of Yao’s work from the 1980s also helps highlight the chief concern about the application-driven funding model. Since this model has a natural bias towards 3-5 year goals and deliverables, can it reasonably support far-sighted work that anticipates and addresses issues not on the three-to-five year horizon? This is a critical question for the nation, since paradigm shifts introduced by TCS (and other fields of CS) often came out of such work. Quantum computing and computational biology in their first decade were two of many “small bets” placed by TCS.

Though individual program officers at CISE find ways to fund some long-term TCS research (e.g., the TCS program at the Institute for Advanced Study receives $300K/yr from a medium ITR grant), the question remains how much these are happy coincidences –the TCS researcher teaming up with the right project; getting reviewed by the right panel and program officer– and whether it is prudent to entrust an important part of the nation’s research agenda to chance events. Also, rising proposal pressure in CISE programs is likely to make such “happy coincidences” more infrequent.

(B) Failure to realize the benefits of TCS’s unique holistic view and “unexpected connections.”  TCS is a coherent science rather than a collection of disparate algorithms for disparate applications and relies for its impact on a large conceptual framework. Funding only a few pockets of TCS fails to feed this framework and also will miss out on “unexpected connections.” A look at recent TCS breakthroughs listed in Appendix A  shows that, although cryptography is thought of as related to computer security (and thus funded exclusively through Cybertrust now), work in cryptography also motivated –via an indirect path– breakthroughs in AI/Data Mining (boosting), Information Theory (list decoding of error-correcting codes), and complexity theory (PCPs). In turn, some of those breakthroughs (e.g., PCPs) then proved useful in cryptography research.

One should also realize that boosting was completely unanticipated by AI researchers, and list decoding by information theory researchers. None of TCS’s breakthroughs from 1990-2000 mentioned in this document were foreseen in 1989, not even by the researchers who made them. Because of such uncertainties, NSF historically maintained a viable TCS program that funded a diverse body of good researchers (albeit with very modest grant sizes). In today’s funding model, TCS breakthroughs of the 1980s and 1990s would probably have been missed.

(C) Failure to train the right workforce. As detailed earlier, TCS PhDs of the 1980s and 1990s helped computer science face many new challenges and pushed it into new opportunities. This group’s impact is surprising given its small size —TCS’s PhD production has always been modest owing to chronic funding problems. The likely explanation is that they were highly trained in a large set of analytic techniques (the large body of existing TCS work) and imbued with TCS’s multidisciplinary and integrative worldview. This made them effective and flexible. It is unclear if today’s funding model is training such a workforce.

4) NEEDED, A REVITALIZED TCS PROGRAM AT NSF

Given the high impact of TCS work in the past decade, the ambitious agenda for the future sketched in Section 2, and the important role played by TCS alumni in industry and science in recent years, there is a strong argument for NSF to revitalize the important research and training agenda of its TCS program. The fact that the current budget pays for only 13 new regular grants per year and trains only 10-12 new TCS Ph.D.s each year in all of U.S. seems alarming. Furthermore, TCS faculty are crucial for CS research and training at all levels, including undergraduate training.

Main recommendation: NSF should revitalize the TCS program and fund it at the level of $18M/year, about 3% of the CISE budget. This modest figure is derived from weighing the ongoing acute budgetary crisis at CISE against the vast likely benefits to the nation’s future scientific, technological, security, and education infrastructure.

Though the design of the program would require careful thought, this budget can support for example roughly 100 researchers (in most cases, with a regular 3-year grant). Since the number of TCS researchers at the top 25 CS departments (US News ranking, 2002) alone exceeds 100, the proposal quality is expected to be very high. In a steady state the program would produce about 25 new PhDs per year —a reasonable figure given industrial demand and the replacement rate for existing pool of TCS faculty in the US. (Compared with other areas of CS, one sees a more uniform age distribution among TCS academics owing to modest PhD production in past decades.)

The expanded TCS budget could support a CAREER program (5 grants per year) and a postdoc program (8 per year). The latter is crucial since 21^st century science requires exposing researchers to a variety of problems and modes of thinking. As TCS grows more multidisciplinary, there is a strong need to adopt this training model (which is common in Physics and Biology).

Strategic considerations: 21^st century competitors of the US such as India and China (whose expatriates already constitute a significant fraction of the CS&E community in the US) will try to compete with the US in producing the next generation of computing technologies. Recognizing the increasing role —as mentioned earlier—played by good ideas and algorithms in these technologies as well as the historical role played by TCS in founding and maintaining CS research and education in the US, these countries are starting with a focus on TCS research. The superior math education in these countries also gives them a built-in advantage. At the same time, enticed by improved research environments in their home countries and funding difficulties here, a wave of Europeans are heading back across the Atlantic.  There is a need to keep the US competitive, especially since its strongest suit against lower-cost competition is the realm of ideas.

Recently, the Chinese government managed to attract Andrew Yao, a Turing award winner and TCS pioneer (one of the founding fathers of cryptography and quantum computing), toTsinghua University to jumpstart an ambitious new program in CS research and training. India already has several strong TCS groups one of which produced the breakthrough in primalitytesting in 2002  that drew great media attention. European TCS is also booming. The Federal Institute at Lausanne has managed to assemble (with generous offers) a formidable group of TCS researchers, including a Berkeley professor and Monika Henzinger, Google’s chief scientist until 2004.

Appendix A: Brief history of recent TCS breakthroughs

To illustrate our point about TCS making unexpected connections, we sketch the history of a few representative breakthroughs from the 1990s. Such connections are difficult to fund in the application-driven model.

• Boosting. Work in early 1980s (Yao’s work on hardness amplification for cryptography, Valiant’s PAC learning model) –>  First “boosting” algorithm (Schapire, 1989) which was clearly impractical –> AdaBoost (Freund and Schapire, 1995); a practical algorithm that quickly became a pillar of AI, Data Mining, etc. (a recent textbook in the field calls it the “best off-the-shelf classifier in the world”). It won the ACM Kanellakis 2004 award for theory & practice.
•  Random graph models. Invented in 1959 (Erdos and Renyi) –> Studied in discrete mathematics and TCS for three decades which greatly refined our knowledge –> in late 1990s, became a popular and influential tool in reasoning about many large networks, including word nets, the internet, and the human brain, with connections to physics and biology (scale-free networks).
• Quantum computation. Suggested as a possibility by physicists (Feynman, Deutsch) in early 1980s –> early 1990s; STOC/FOCS papers (Bernstein-Vazirani, Yao, Simon) formalized quantum turing machines and quantum circuits, and suggested that they may be more powerful than classical computers because they can implement the Quantum Fourier Transform–>Shor’s factoring algorithm (1994) –> mid to late 1990s; TCS papers described how to introduce robustness in the quantum model and allow it to tolerate errors/decoherence –> today QC is a thriving sub area at the intersection of physics, chemistry, and CS.
• Hashing. Rudimentary forms discovered in 1950s –>First STOC/FOCS paper in 1979; universal hashing (Carter-Wegman)–> hashing theory developed over many years in TCS papers; few immediate applications –> Late 1990s, Akamai is formed thanks to the TCS idea of consistent hashing. Hashing-like ideas also heavily used by Google and other companies that work with large data-sets.
• Interactive and probabilistic proofs and an application to coding theory. Interactive proofs invented for cryptographic purposes (GMR, mid 1980s) –> in early 1990s, connection is made to probabilistically checkable proofs and leads to important extension of the classical theory of NP-completeness (namely, for many NP-hard problems, computing approximate solutions is NP-hard too) –> in late 1990s one of the offshoots is an algorithm for decoding error-correcting codes (Sudan, Guruswami-Sudan work on list-decoding) that is considered one of the major theoretical and practical advances in information and coding theory of the past decade (featured as a “discovery” on nsf.gov).
• PCPs and  loss-resilient codes:  PCP Theorem proved (1992, AS, ALMSS) –>1993 Sipser and Spielman rediscover expander codes in an effort to simplify proof of PCP Theorem–> late 1990s; new constructions of low density parity check codes (Luby, Mitzenmacher, Shokrollahi, and Spielman; cowinners of the 2002 IEEE Inf. Theory Society best paper award) –> 2000 and later; basis of major startup Digital Fountain,  a new paradigm in coding theory, and  basis of  DVB-S2 standard for satellite transmission of television.
• Smoothed analysis: (Spielman and Teng, 2001) Combines worst-case analysis with average case analysis; a new paradigm for algorithm analysis that helps explain the everyday behaviour of some popular algorithms (such as the Simplex algorithm for linear programming).