Part II Principles of Communications, 2015, to Nov 20

this week, covered scheduling, work conservation, max/min fairness, and PGPS approximations + queue jump!

Part II Principles of Communications, 2015, to Nov 13

Optimization (Nov 9) - background paper:-

from Princeton group

TCP in the wild - Optical Carrier Speed
table + Reminder about R-squared

Schedulers&Rounds....up to WFQ.

Part II Principles of Communications, 2015, to Nov 6

Flow Control, Congestion Control,
open and closed loop systems

Control Theory -
time domain model
transform to frequency domain
recipies for laplace transforms
stability & efficiency
proportional, integral and differential (and PID) controllers.

Online slides (PPT and PDF) are ok -
apologies for symbol/font problem in some of the printed pages!

Part II Principles of Communications, 2015, to Oct 30

Previously, Compact routing, Central routing (fibbing to link state),&path vector

This week covered
interdomain routing, including AS paths and deadlocks,
for which see interdomain revision notes/slides
+
multicast,
+
random routing

Just started on error and flow control.
[As usual, wikipedia is great on gaussian elimination ]

Pretty much as per schedule

Part II Principles of Communications, 2015, to Oct 23

This week has been about inter-domain routing, and BGP.
Covered background business relationships (peering, customer/provider etc), the protocol, the attributes/selection, SPP, and discussed scaling, convergence, and problems (like bad gadgets, wedgies) - as always, data is out of date, but Geoff Huston to the rescue...

Part II Principles of Communications, 2015

This week (to Dec 16) I should have covered the graph material (random graphs + alpha&beta models of small world/clustered graphs), and
Compact and Centralised routing - viz
http://www.cl.cam.ac.uk/teaching/1516/PrincComm/slides/schedule-2015.html

On graphs and networks there's a new really nice book by Jon Kleinberg


There's some lack of precision about the terms "small world" but basically, (wikipedia is your friend) a scale-free network refers to the power law degree distribution, and consequential small diameter (and some clustering), which leads to the small world property. Not all small world networks are scale free, but scale free networks are small world...

The Smell of Memory

scientists in cambridge have recently figured out how to code the smell of memory, not just a smell of one thing that evokes a particular memory, but the underlying phenomenon that is memory itself. It turns out that it is not so abstract, and that there are only really 7 key parameters (somewhat like taste, which is, of course, related to smell in any case). Working backwards from the examples of smells that evoke memories, using a statistical technique called PCA, scientists can now code the entire space that is memory - so not only evoking a particular memory, but replaying everything at once.

Of course, there are severe dangers of synaesthesia with this technique, so it will only be allowed in key, socially beneficial situations, such as court cases, or TV interviews with politicians.

And it must be noted that there will inevitably be people who have an innate fear of smell - loosely related to the smell of fear, but far more disabling in this context, except where you'd like the right to be forgotten - de-oderant amnesia.

Re-use ill-considered (twitter and hypothermia)

I've been reading a lot about ethics recently for a forthcoming workshop in Oxford on the topic.
It seems that a lot of the book keeping elements of ethics have been defined (I guess, perhaps, in reaction to the lamentably long list of unethical things that are done by all and sundry in online media commercial appropriation of the essence of you, and dodgy medical research re-owning folk knowledge on drugs from rainforest eco-systems, or testing stuff on people who have no political or economic choices...

So there's a long list of stuff we (as researchers) have to go through.....

but it seems to me that quite near the top of the list ought to be something about re-use

In computing (and in general in engineering), re-use of stuff (re-cycling harware, and re-cycling good ideas, or software) is regarded as a good thing - rep-purposing too - the internet came out of dual-use (re-purposing a survivable defense network, as a cheap extnesive global communications utility for the public)...

but the real elephant in the room for me is re-use of stuff in a new context without ethical consideration.

Let me give two examples (from the title of this post)

1/ someone (NOT ill-advisedly) tweets that, unless the snow in an airport is cleared soon, he will blow it up. This is a daft joke which maybe to his friends is funny coz he's that sort of a guy.
That's not the problem. THe problem is that it got re-tweeted or forward to the police - whoever did that, did they stop to consider the original intent. Or was this thoughtless? or possibly even malicious? why did the police not regard this as potentially a "crank call"? were they not wasting police time

2/ research on hypothermia received a boost from the Nazi doctors trying stuff out on people in concentration camps. The research actually turned out to be useful. Should we deny ourselves the benefit, despite the awful provenance of the results?

Some of this can be reduced (in a classic reductionist manner) by looking at cost-benefit tradeoffs. What are the risks the tweet really is a bad guy? what are the chances that if we use the nazi medical results, someone will start a land war with russia, to aid in their drug discovery programme?
How much extra work do we have to do to make deciding the right way about the incentives, or the re-use of results?

Why do I care?

Well, its clear that many open, public-minded people constrain themselves from doing potentially valuable research by setting barriers before working out the cost-benefit/incentive balance, whilst at the same time, a lot of industry just goes ahead and does it, and fixes things up after the event.
Is there a middle ground?

I'm suggesting that considering re-use and the safeguards one should put in place for that, might give a way to evaluate whether something is ethically acceptable or no.

It could also serve by offering "re-use cases" which might be easier to explain to people as part of the "informed consent" steps of any ethical experimental design.

As more pressure is put on us to do work with larger and larger data sets (whether the GCHQ surveillance data, or police crime/geo-loc data, or NHS care.data) we need to figure this out soonest.

Intellectual Property and Production - workshop in Law, 24.1.2015

at Wolfson College, 25 Jan 2015
Organised by Center for Intellectual Property and Information Law

Jennifer Davies introduced the workshop (6th in a series run by CIPIL ) and reminded attendees this was about production (and place!)

Session 1: Producing Output, led by Lionel Bently

Tanya Aplin: 'The Impact of Prosumers on Photojournalism' - this talk mapped out how the massive rise of amateur photography and the ubiquitous presence of cameras (especially in phones) had given rise to the de-skilling of the area of photojournalism, starting especially in disasters and emergencies (Katrina, Tsunami, Arab Spring etc), where classical photojournalists might not be on the scene for days in any case, but now supplanting every day coverage of events. The talk then went on to the new businesses that had arisen to "professionalise" the contributions by the public, and new agencies that would find takers for pictures and pay producers (albeit massively less than the famous photojournalists of yore).

Great talk - i think to be fair, the "professionals" always over-stated the skills you need to be a good journalist - many amateurs are massively better than many paparazzi - see my friend tim harris photos - he's a research leader at Oracle labs....this is also true of bloggers - for example my local kentish town blogger produces more timely and better job than the main traditional local newspaper (in my view:)

Alan Durant: ‘Kinds of Work in Copyright: a Semantic Perspective’

This was a foundational take on the triptych "Original Literary Works" unpicking the individual and combined meanings over history and showing how ambiguous the terms sepeaately and together were and still are. THis has important consequences for public and other stakeholders understanding of the relevant law!

Hye-Kyung Lee: ‘Media fans as new cultural intermediaries’

This was about fan contributed works with a new spin - the Manga translators - fandom who take japanese and korean comic art, and produce versions for other markets! Again (as with the first talk in this session) the emergent business models have first been squashed, but then embraced and extended by the original Manga production houses. Fans reactions vary (as you would expect) from approval to "uncool" - also, interestingly, cultural differences mean that Chinese reaction is quite different than other countries in this regards. I asked if anyone has tried personality profiling (c.f. psychometrics facebook app in cambridge) to see what sort of people enjoy these activities - is it mostly about fame, social capital, etc - inclusion - etc or do some really want to make it like their heroes in the original comics? or a mix (changing over time). Was reminded of two related stories. (Anecdotal) - 1/ The Dr Who fan contributed plots and characters were threatened with a lawsuit for copyright reasons, but then it emerged some of the writers of Dr Who had been reading the site, and may have inadvertently used material and fans suggested that they might countersue - so a quid pro quo was reached:) 2/ My cousin was teaching computer science in Brasil and translated US text books by reading then speaking aloud in portuguese, to a dictation/speech to text system (Dragon Dictate) - students bought the original book, so there's no loss to publishers or authors, but were given handouts of the text part in their own language.  Publishers became interested (low cost way to get foreign language editions of books....and discover markets).

This element of fan led A&R seems like an obvious way for producers of new work who live in the "long tail" of the popularity distribution to find their market, and for new fans to find content. Seems like a good thing - for a given area, it may not be a zero sum game  although over all content, I guess the population does have a finite disposable income. However, this new mode may lead to a wider breadth of availability, perhaps at the expense only of the few people at the very tip of the popularity (U2, Beyonce might lose a few percent of their gazillions) - maybe Thomas Pikety will approve!

Session 2: The Means of Production (I) led by: Ian Walden

Jon Crowcroft: ‘Software Tools and Die’
here's my talk which is mostly just about how we write software but also a plea not to do s/w patents (the clever bits are just math) and how copyright is ok, but there's lots of different uses (license models) which can all work (and co-exist)

Catherine Seville: “Controlling the Production of Literary Works: Hard
Then, Impossible Now?

This was a fascinating talk about the ways in which the technologies for production have always seen (mostly failed) attempts to control - from limited access to printing press, to control of rights to publish, through to DRM etc - really interesting...

Simon Eliot: ‘From 'Literary' to 'Commercial' in the Registry Books of
the Stationers' Company

Beautifully read and presented talk about this history and hilariously incompetent antics of rhe Stationers' company (registry for all things trademarkish) esp in the 19th century, which some fabulous graphic examples of Victorial graphic design for a wide range of useful, daft, and sentimental works. Sheer diversity of display is astonishing.

Session 3: The Means of Production (II) led by: Andrew Griffiths

Sean Bottomley: ‘Trade secrecy and production during the late
seventeenth and eighteenth centuries.’

Lovely talk about Worshipful socieiies and their control of their magic pixie dust techniques-  interestingly, the use of sanctions against people for revealing these tricks to "foreigners" (i.e. non guild members) was relatively rare in practice.  It makes you wonder why the Worshipful Company of Information Technologists was set up - What have they got to hide???

Dev Gangjee: ‘Why Wine is Not a Commodity: Geographic Indications,
Place and Process’

Great talk as with all the talks, really well presented and clear) on "terroir, and the way GIs are being used more and more, and yet have very little public recognition yet (outside of the original "Appelation Controle) - I asked the questions a) how "little britain" is all this and b) can you have a GI for "produced near here" for any definition of here (i.e. eco-didn't fly far food) - answer, yes...

Theresa Lopes: ‘Trademarks and Production of Consumer Goods from an
Historical Perspective’

Great econometric analysis of a large body of data from several places showing how IP protection trends track a) innovation b) the economic growth/shrinkage - a lot to take in - hopefully, we get some slides/paper post workshop!


Session 4: Geographical Delineation, led by Session leader: Graeme Dinwoodie

Sun Thathong: ‘A Marxian interpretation of the traditional knowledge
debate: the role of IP in the
coexistence of primitive and capitalist modes of production.’

Fun stuff -not quite as alarming as it sounds - basically, traditional knowledge is folk lore and crafts embedded in simple societies and held in common. It is being ram-raided by developed countries profit led companies (most obviously, plant medicines in rain forests being patented by big Pharma). This is about the moves to try and figure out a range of IP models that will appropriately recompense those "simple" societies (which, if course, are never so simple). Main bug is the hilariously naive Marxian description of primitive communism, which an anthropologist would have a field day with (literally and figuratively), but the model economically is good.

Here I had to leave to go to a memorial Mass for my brother in law, Declan McKeever
so I missed one of the organisers papers, which was a shame as it was

foundational to the main purpose of the workshop:

Jennifer Davis: ‘The End of Trade Marks as an Indicator of Place and

the Implications for Labour’

Graham Dutfield: ‘The compulsory working of patents and developing

countries.’

Henning Grosse Ruse-Khan: ‘From Local Manufacture Rules to Import

Barriers in Global Production Chains’

Science and Policy - Why should they pay attention to us?

Reading the latest CSAP (center for Science and Policy) report on "future Directions for Scientfic Advice in Whitehall" is quite frustrating if you are a geek.

Several behavioural weirdnesses define geeks, and these matter:

1. geeks tend to read about anything whatever their core training is, whether climate science, social media analytics, psychology, behavioural economics, and XKCD
2. notwithstanding Steve Hand's memorable pub rant[1], politics appears to be quite a lot simpler than a physics (Natural Sciences) or computer science or engineering degree, really.
3. they witness many people in political decision making roles who are actually less qualified even in terms of soft (social) sciences (lets not rehearse the PPE pub rant again just yet [2])

So what does this lead to?

1. incredulity when governments do not act on scientific advice (drugs, immigration, climate).
2. frustration when governments offer explanations as to why they cannot act on said advice.
3. strong inclination to walk away from bothering ever again to offer advice/evidence.

Far from this being something scientistcs should apoligise for, given the nature of the public's alienation with current western democratic policies (e.g. economics of austerity), it behoves politicians to rethnk how they react to public advice:

1. scientists have a methodology (atually lots, but lets stick with Popperian classical Object Knowledge for now).
2. Theories are falsifiable - the latest theory is "best of breed", that's all its merit is.
3. We dismiss theories when new ones come along that meet the criteria (better fit, simpler, more elegant -- pick any).
4. We change our minds. 

Indeed, there are honourable occasions (e.g. discovering that stomach ulcers were caused by bacteria, or the italians finding that their neutrinos did not go fast than the speed of light, or the cold fusion fail), when this is very public, but it happens every day on a finer granularity

I think the time has come for scientific method to be applied by politicians. Just as Jeanette Wing argued for computational thinking to be part of everyone's intellectual landscape, scientific method has already been embedded in everyone's subconscious for some time (e.g. since the Age of Enlightenment, aka Age of Reason)

Why not? As Oliver Cromwell said to one government (and remember what happened to them 

Think it possible you may be mistaken.

CLuDo

CLuDo

All bar one of the suspects was ruled out through a rigorous process of logic
and fermentation.  Suspect B was never identified, although her love of Citrus
flavoured chewing gum inclined Devonshire to discount her on the basis of the
lack of scent in any of the crime scenes. The fine detective had the measure
of Napier, and deemed his extremely asymmetric length arms to put him beyond
the reach of the law.  The recent Turkish immigrant who went by the moniker Moosh had an alibi (waylaid in a public loo by a nearly terminal bizarre
kebab accident). The Polis had no beef with Professor Baron, who was in any
case too absent minded to remember who could be next o nthe serial killer
list. Ms Bath was in the Ale House, where she tended to hang out with other
birds in hand. Dr Burleigh was too gentle a character, despite being a well
known Arms dealer.  The reverend Carlton was left handed, whilst the
Carpenters were both right handed, which saw them in the clear.
Thomas Champion was in london rowing, on the  Thames that day, and indeed,
had turned a corner since leaving the county seat for town, and given up his
unnatural addiction to Dobblers. (Dobblers is that well known breakfast dish
that looks like a classic grill, but in fact is made from dog & pheasant
and isn't as illegal as it is unpleasant).

The Earls of Beaconsfield and Derby were both out at a shoot, and so the
inspector was shot of them, even before five bells. Indeed, he thought to him
self with a wry ha-ha, pigs might fly and his golden hind come in, before
they'd commit any such gross moral turpentine. Henry was OK, since he'd made
peace with his Armenian girlfriend Ishca over the proper use of feathers in
millinery.

It was known that Milton was blind drunk, and waxing eloquent over some
jolly waterman about his time playing frag piano in old Orleans.
The chancellor was above suspicion, as were any of the occupant of the
Regent house. All five of the Irish brothers were known to react badly to the
men in blue, a red rag to a bull, but the inspector rose to the challenge, and
avoided a crowning.  Rupert Brooke was with Milton the whole day, according
to the sheep rustler known to everyone just as The Eagle, who had dropped in
after some wild spread betting.

Radegund's sainted aunt claimed he was down at Ally Pally, his Alma mater, and
the only anchor in his peripathetic life.
The inspector would give drink bakers dozen once the moon was over the yard
arm if that blackamoor's head was capable of such dark thoughts.
Devonshire asked his trusty sidekicks Argyle and Clarendon if they thought
there was anything in the rumour about the boats? Dr A saw on the
British Queen not, whilst det inspector C, smelling like a
brewery concurred. Devonshire looked at these two interchangeable chaps, like
peas in a pod - you couldn't tell if you swapped them, castle-to-castle like.
He hadn't graduated in the Jubilee year to waste time like this. He had other
buns in the shop to fry.

Back in  Cambridge feeling blue drinking a hog's head of big black cow and watching the
cricketers cut down another elm tree, failing to impress, as they fought
by George to keep the greyhounds and haymakers at bay, Inspector Devonshire
wondered if perhaps the evil genius artist, Geldart was behind it all.
Granted, he had the locomotive and was a man with a means, if not completely
in a pickerel. After all, he was known to have a predilection for chasing the
Green Dragon down King Street at quite a run. Many times, Dr Kingston had
tried to wean him off, but he would claim to be a master of the Marinade,
although everyone knew he was just driving them up the Maypole.

So summing up the first victim, Panton was found  bashed in by a
globe carved curiously with Fleur De Lys; the second, Portland,
rolled around a Fountain, pursued by a green manatee. The third,
Ms Parrot, crushed beneath a free press, like grapes, blood
spoiling all the nice mitred corners, pouring out like an old spring, only
attractive to the rats. The fourth, Salisbury trapped between the mill stone
and a rock, but curiously tied up with rope and twine. The fifth was drowned
regally when his ship ploughed into a dead end.

At six bells, listening to Bert Jansch playing
down by black Waterside on his iPod, the inspector suddenly remembers Arthur C Clark's story from Tales from the White Hart
(the one with all the violations of Sir Isaac Newton 3 laws of droog).
he lit a fine Unicorn cigar with a White Swan vesta matches, and decided to
see if the Wrestlers were still slugging it out over a bacon, lettuce and
tomato roll. As seven starts came out, the inspector took the last tram home
but fell asleep and landed up in the depot once again.

principles of communications, 2013/2014, end of week #7 to L22

This week, we covered shared media & ad hoc capacity, and started on traffic engineering.

A sharp question on proportional fairness in earlier material prompted me to notice that that isn't well contrasted with max-min fair sharing -- It turns out (as often with technical areas) Wikipedia has a nice explanation - see this article on
proportionally fair w.r.t weighted (max/min) fair queues

Next week will finish traffic engineering and wrap up with summary of course.

principles of communications, 2013/2014, end of week #6 to L19

This week have done scheduling, queue management and switching
and just about to start on shared media

One interesting point historically -the colossus computer at Bletcheley Park built for code breaking was not a von Neumann classical architecture computer but was a "switched programme" machine  - this made it incredibly fast (for a 1940s design) although incredibly inflexible -- and it took a very long time for people to catch up on a standard desktop (about 50 years) - amusingly, about as long as the Dr Who series has run on BBC TV:)

principles of communications, 2013/2014, end of week #5 to L16

This week, control theory and optimization...

Some minor inaccuracies in slides have been corrected in the online copies linked from the course materials page...[or will be as soon as I can get powerpoint with the right fonts:) - the key error is in the calculation of the steady state error of the proportional controller - for some reason, there's a subtraction of the two terms for U(s) where it should be +
(KUs + Rc) / (s(s+K)
I think {need to check this:) it kind of makes sense (if the completion rate increases, the admission rate should increase....)

then when we take the limit of s(U(s), as s->0, we'll get Us + Rc/K
so ess (error in steady state) is Us - (Us + Rc/K) which gives us -Rc/K
(i.e. the answer is right, but the system response wasn't...will check and correct soon...

again, to note, the chapter on control theory in Keshav's book is very clear if you want alternative source + some nice example problems.

principles of communications, 2013/2014, end of week #4 to L13

Error, Flow and Congestion Control done (99.9%)

further reading - maybe - on Network Coding (see Digital Fountains)
and on what's in Linux (CUBIC) and Windows (Compound) for congestion control, and what real traffic actually looks like - see CAIDA
http://www.caida.org/home/

next week: control theory...and optimzation:)

principles of communications, 2013/2014, end of week #3 to L10

This week we covered routing -

there's one egregious error on the slide explaining Dijkstra's algorithm in Link State where the sign on the comparison is the wrong way round (well spotted students!) - I leave it as an exercise for you to find, as it makes for careful reading:-)

In Sparse Mode, we use Rendezvous Points to coordinate a single RPF tree around a designated/configured router (maybe one for each of a different block or subset of multicast addresses) - there's no guarantee the RP is in a sensible place, although the switch from RP centric tree to source based tree after an traffic flows helps reduce latency -  automatic placement of an RP to be in the "centre" of the group would be a solution to the Steiner Tree (Min spanning tree) problem which is NP-Hard, although there are polynomial time approximation algorithms for it (but you probably wouldn't deploy them in routers, but in a network management system for e.g. a gamer or trader network, this might be sensible)

One other note - consistency, symmetry of routes, and so on - IP and IP routing make no guarantees about this at all! BGP (inter-AS routes) are often asymmetric...recent computer science work on building new protocols that provide global consistency during route update and computation does exist, but is still research, largely....although the techniques are promising!

Next week, errors, then flow and congestion control.

principles of communications, 2013/2014, end of week #2, to L7

To note for today- the slide on graphs, with Edge and Node list has a list of all edges, alongside o nthe right list of nodes  - the list of nodes isn't meant to line up with the list on the left - its just a list for node i=1-5, what other nodes, in the directed graph,  are adjacent (look at arrows on edges - note in 2 cases (1<->2 and 5<->4, they are bi-directional)....



fun references today:-
Ghost Maps

Collatz

Kirchoff

Erdos

Small Worlds...

DDOS visualised

Couple more corrigenda/errata
1. in the alpha/beta models of random graphs, there's k used for average degree of the net (e.g. pN in the alpha model), but also used for the toal number of edges (N*(N-1)/2) - so take care with k
2. there's an expression in the slides about max-flow in DAR (the "Sticky Random Routing" for the telephoen net) for using Erlang's call blocking probability for a given link, then work out what the toal capacity will be for 1 hop and 2-hop/tandem routes - this has n, which is number of calls you get through, then mentioned a technique called LP  to solve the maximisation problem given in terms of sum of calls that get through (or are blocked) over all direct and tandem routes- we are'nt covering that technique this year, but LP stands for Linear Programming, and is fairly straightforward if you want to look it up - it is commonly used in optimisation and shows up in Operations research/Logistics (freight etc) and so on all the time.

principles of communications, 2013/2014, end of week #1, to L4

We have now covered Systems, and Layers (lawyers)...

Next week, Graphs, and Routes!

principles of communications, 2013/2014, L1

Today this course starts: principles of communcations

This blog will be where I put errata, answers to questions, and just generally track progress of where we've got to for students and supervisors....

Today [11.10.13] got as far as 1/2 way through Systems lecture - Monday
intend to finish that and go about 1/2 way through Layers material:

slides

Publication Culture in Computing Research Design for impact: Rethinking academic institutions from the ground up

Why do we pretend that a publication is an event, rather than a part of an ongoing
process?
Computer Science is a Soft Subject. We create artificial systems/artefacts, and explore
their behaviours. We then report on this by talking about the behaviours at workshops
and conferences, and writing about the systems in papers for web pages, online
archives or even traditional print journals.
People assume that the artificial dichotomy between social events (workshops,
conferences) and archival repositories (journals and the like) is right. And some of the
debate about CS publication culture is oriented around trying to get people to use
these two modalities  more like other disciplines.
I think this is fundamentally wrong, and flies in the face of real scientific method.
Science does not deliver truth. It delivers things that work, and explanations that are
the best, current, simplest ones (c.f. Popper on Objective Knowledge, and of course
Occam’s Razor).
This means that a work is not the final word. It is just the current word. A goal of this
proposal is to reduce the “slice and dice” culture present today due to various perverse
incentives.
So the notion that an “archival paper” has been thoroughly checked and is infinitely
more “correct” than a “rapidly” reviewed conference submission is not tenable. There
is every chance that during the necessarily longer process to create an archival version
of a work, subsequent work has improved over the results. Hence much archived
material is actually less accurate because it is less timely.
The solution, for me, is to remove the notion of immutable publications, and admit
that we should update work continuously
This can apply to the entire process of socialising our work, hence a dialogue (or
multilogue) between authors, reviewers and readers, continually adds accuracy or
timeliness (or invalidates a work).  The same can apply to citations (which should, by
the way, have a “sign bit” to indicate whether the citation is building on fro ma work,
or citing it as the thing the new work invalidates).
Recognising this mutable publication model, would allow work to be presented at any
point along the “production line”, perhaps merely by “acclaim” - some work has
reached a point where it is mature enough and timely and interesting enough to merit
presentation at a social event (workshop or conference) - this could happen before or
after some notional point when it is recognized that an archival version is the current
best knowledge we have (a rare event).

Along side this continual process, I think one would have to abandon ideas of
anonymity in both authorship of work, and reviews/critiques (viz, the “dialogues”
mentioned above could only work in that open way). It goes without saying that code
and data associated with a systems’ behaviour should also be openly available as part
of this ongoing process (after all, since when did we declare code “bug free”
correctly? Why, therefore do we declare journal papers “correct”?).
Finally, this isn’t exclusive to Computer Science, but we built the tools that would
make the new approach viable, so we should use them first.
In fact we also have the next generation tools for this – we just need to combine Arxiv
with Github (versioning repositories)
1
.
Causes of paper count inflation.
CS is notable (in most branches at least) for submitted to conferences more than
journals. There are two pressures to do this
1. Urgency
2. Promotion
CS is a young disciple, and the young are noted for being impatient and impetuous -
our slogan might even be said to be “Publish Early and Publish Often”
2
.
Urgency
We live in a nanosecond world. More than other disciplines, partly because we built
it.
We supplied the tools and tool chains (the net, e-mail, the web, PDF, bibtex/latex,
databases, HotCRP/EDAS, etc)  that let us cooperate to develop ideas, systems,
results, and write papers faster, and deliver them for review, editing, and presentation
more quickly than any previous generation. Surely, other disciplines use the tools, but
we live and breath them.
As a result, there’s a feedback loop between publication of hot new work, This instant
gratification leads to an increase in the rate of submission.
Our profession has also a tendency (at least anecdotally) to attract a share of people
with OCD/Attention Deficit problems, who maybe (amateur psychologist’s hand
waving here) seek instant rather than deferred gratification.
                                             
1
 Github because we want distributed repositories to avoid re-concentrating power in
one place all over again.
2
 I could speculate here about whether these factors also contribute to the gender
imbalance in Computer Science as a profession and academic career (whether
directly, or simply as proxies for a root cause).


Promotion
Our academic research culture is funded largely by tax payers money (NSF, DARPA,
EU), and the tax payers seek metrics to see their money is well spent, and they seek
such feedback on an annual basis. Paper counts (and to a lesser extent, citation
counts) serve this. The same problem (inflation) has hit the industry research and
development world, where patents are a proxy for real work, and are rewarded.
The amount rather than significance of work is measured - hence, the aforesaid dice
and slice approach to work, producing minimal publishable units, and multiplying the
number of venues and publishable units year on year.
Because CS is young and vigorous, we have in the past been able to keep up with this
inflation. We are close to the limits though.
In the UK, we have a national Research Excellence Framework, for which researchers
in universities do not return all their work. Instead, every 5 years, up to 4 “outputs”
(e.g. papers) are returned. Secondly, and in addition, impact stories (pieces of work
10-20 years old, that have had a long term effect on the world, economically, socially,
or in terms of further developments in a discipline) are employed.
It will be interesting to see the outcome of this process, but for me, it is probably a
better basis for looking at some one person, or groups progress, so if we were to use
these sorts of indicators for tenure or similar, this would remove the aforesaid
perverse inventive to maximise the number of publications.
Acknowledgements
Thanks to Richard Clegg and Ioannis Avramopoulos for comments on this draft.