Archive for category general

Debate: U.S. Airports Should Use Racial And Religious Profiling

The setup from Intelligence Squared:

On Christmas Day, 2009, twenty-three-year-old Umar Farouk Abdulmutallab attempted to blow up Northwest Airlines Flight 253 using explosives hidden in his underwear. A string of missed opportunities and errors by government security agencies culminated in what President Obama would declare a “systemic failure.” Is scanning everyone with expensive, high-tech equipment the best use of limited resources? Or should we use the information that we have—the knowledge that, while all Muslims are not terrorists, most terrorists are Muslim.

U.S. AIRPORTS SHOULD USE RACIAL & RELIGIOUS PROFILING (iq2us.org) from Intelligence Squared US on Vimeo.

I think this debate should be re-framed: Should law enforcement use every tool at their disposal, which includes profiling, or should they refrain from using tools that may offend some people.

In the beginning the moderator concedes the main point, that the majority of recent (within the past decade) terrorist attacks have been committed or attempted by men who have a common tie to Islam. If this is true (a fact that was never disputed), then it makes the validity of including it as a metric a foregone conclusion.

In fact, the only objections given by the opposition were

  • Judging people based on nationality is not sufficient to determine whether someone is likely to be a terrorist
  • Not all terrorists are Muslims
  • Not all Muslims are terrorists
  • Its a violation of civil liberties to question a certain group more than others

To these, the responses were given

  • Religion and race are not the only metrics used and the agents involved aren’t the only ones doing the analysis
  • The majority of terrorists in the past decade (or more) have been Muslims
  • The size of the overall population is irrelevant, what matters is the statistical likelihood that a terrorist will match the overall profile
  • Civil liberties aren’t violated by mere suspicion. They aren’t even violated by extra law enforcement attention (interrogation, scans, etc.)
  • It makes us less safe to waste law enforcement resources on “random” searches.

What this debate really highlights is how most people, even supposed “experts”, either don’t understand how statistical analysis works or deliberately choose to misconstrue the facts. It also highlights how our culture’s myopic drive towards political correctness makes us less secure as a result.

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Engineering new life

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Javascript performance

His biggest point is “do not optimize prematurely”. This is a sentiment I’ve heard a few times. Fred Brooks emphasizes it in Mythical Man Month, and Eric Raymond harps on it a bit in Art of Unix Programming.

Another point he makes is how using “weird language syntax” like double bitwise not is sometimes faster than their functional equivalents like parseInt.

And one surprising revelation (for me anyway) is that unrolled loops can sometimes be faster.

Overall, a great presentation, well worth your time if you work with javascript a lot.

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Unlearn Your MBA by David Heinemeier

[HT Fat Angus]

Here’s the Stanford page for more info.

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How to choose strong passwords that live in your head

[HT Lifehacker]

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The Economist on Biometrics

[HT Bruce Schneier]

Here’s an excellent article on the use of biometrics in security system. Here are some highlights.

Intro

Authentication of a person is usually based on one of three things: something the person knows, such as a password; something physical the person possesses, like an actual key or token; or something about the person’s appearance or behaviour. Biometric authentication relies on the third approach. Its advantage is that, unlike a password or a token, it can work without active input from the user. That makes it both convenient and efficient: there is nothing to carry, forget or lose.

Some problems

The downside is that biometric screening can also work without the user’s co-operation or even knowledge. Covert identification may be a boon when screening for terrorists or criminals, but it raises serious concerns for innocent individuals. Biometric identification can even invite violence. A motorist in Germany had a finger chopped off by thieves seeking to steal his exotic car, which used a fingerprint reader instead of a conventional door lock.

Another problem with biometrics is that the traits used for identification are not secret, but exposed for all and sundry to see. People leave fingerprints all over the place. Voices are recorded and faces photographed endlessly. Appearance and body language is captured on security cameras at every turn. Replacing misappropriated biometric traits is nowhere near as easy as issuing a replacement for a forgotten password or lost key. In addition, it is not all that difficult for impostors to subvert fingerprint readers and other biometric devices.

Research findings

The panel of scientists, engineers and legal experts who carried out the study concludes that biometric recognition is not only “inherently fallible”, but also in dire need of some fundamental research on the biological underpinnings of human distinctiveness. The FBI and the Department of Homeland Security are paying for studies of better screening methods, but no one seems to be doing fundamental research on whether the physical or behavioural characteristics such technologies seek to measure are truly reliable, and how they change with age, disease, stress and other factors. None looks stable across all situations, says the report. The fear is that, without a proper understanding of the biology of the population being screened, installing biometric devices at borders, airports, banks and public buildings is more likely to lead to long queues, lots of false positives, and missed opportunities to catch terrorists or criminals.

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Do the images you post online pose a security risk?

Take a look at this report on what may be included in the images you upload for the world to see to find out.

Here’s the abstract:

Unless your digital camera or camera equipped cellphone is more than fifteen (15) years old, the chances are good that any pictures taken with that device contain metadata; which describes the (who, what, where, when and how)conditions under which the picture was taken.  The metadata is stored with the picture in an image file, and goes everywhere the file is copied, uploaded ordownloaded.  This metadata is meant to help us, document the moment a picture was taken, and also to maintain the fidelity of edited or printed copies.  But as discussed in my article on Augmented Reality, once an image file containing metadata leaves your possession, there are a variety of ways in which that same metadata can be used against you.

So, just how dangerous is image file metadata?  In the past, there have been numerous discussion, examples and demonstrations of how much usefulinformation can be extracted from image files.  But publicly, nobody has admitted performing a risk assessment of image file metadata.  I suspect that such assessments already exist, but are probably classified as CUI (Controlled Unclassified Information).  And so, I have undertaken the task of performing aqualitative risk assessment to answer the question.

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The foundation of the internet

In July 1945 Vannevar Bush published a paper titled “As We May Think” in the Atlantic monthly magazine. In this article Bush lays out a vision of the future wherein he hopes we will be able to “wield [the] record for true good”. By record he meant the sum total of human knowledge which has been recorded in a more permanent fashion and made easily attainable.

Here are some selections from Bush’s excellent paper that inspired the internet 65 years ago.

Abstract from the editor

As Director of the Office of Scientific Research and Development, Dr. Vannevar Bush has coordinated the activities of some six thousand leading American scientists in the application of science to warfare. In this significant article he holds up an incentive for scientists when the fighting has ceased. He urges that men of science should then turn to the massive task of making more accessible our bewildering store of knowledge. For many years inventions have extended man’s physical powers rather than the powers of his mind. Trip hammers that multiply the fists, microscopes that sharpen the eye, and engines of destruction and detection are new results, but the end results, of modern science. Now, says Dr. Bush, instruments are at hand which, if properly developed, will give man access to and command over the inherited knowledge of the ages. The perfection of these pacific instruments should be the first objective of our scientists as they emerge from their war work. Like Emerson’s famous address of 1837 on “The American Scholar”, this paper by Dr. Bush calls for a new relationship between thinking man and the sum of our knowledge. – The Editor

Outlining the problem

This has not been a scientist’s war; it has been a war in which all have had a part.1 The scientists, burying their old professional competition in the demand of a common cause, have shared greatly and learned much. It has been exhilarating to work in effective partnership. Now, for many, this appears to be approaching an end. What are the scientists to do next?

For the biologists, and particularly for the medical scientists, there can be little indecision, for their war work has hardly required them to leave the old paths. Many indeed have been able to carry on their war research in their familiar peacetime laboratories. Their objectives remain much the same.

It is the physicists who have been thrown most violently off stride, who have left academic pursuits for the making of strange destructive gadgets, who have had to devise new methods for their unanticipated assignments. They have done their part on the devices that made it possible to turn back the enemy. They have worked in combined effort with the physicists of our allies. They have felt within themselves the stir of achievement. They have been part of a great team. Now, as peace approaches, one asks where they will find objectives worthy of their best.

Of what lasting benefit has been man’s use of science and of the new instruments which his research brought into existence? First, they have increased his control of his material environment. They have improved his food, his clothing, his shelter; they have increased his security and released him partly from the bondage of bare existence. They have given him increased knowledge of his own biological processes so that he has had a progressive freedom from disease and an increased span of life. They are illuminating the interactions of his physiological and psychological functions, giving the promise of an improved mental health.

Science has provided the swiftest communication between individuals; it has provided a record of ideas and has enabled man to manipulate and to make extracts from that record so that knowledge evolves and endures throughout the life of a race rather than that of an individual.

There is a growing mountain of research. But there is increased evidence that we are being bogged down today as specialization extends. The investigator is staggered by the findings and conclusions of thousands of other workers – conclusions which he cannot find time to grasp, much less to remember, as they appear. Yet specialization becomes increasingly necessary for progress, and the effort to bridge between disciplines is correspondingly superficial.

Professionally our methods of transmitting and reviewing the results of research are generations old and by now are totally inadequate for their purpose. If the aggregate time spent in writing scholarly works and in reading them could be evaluated, the ratio between these amounts of time might well be startling. Those who conscientiously attempt to keep abreast of current thought, even in restricted fields, by close and continuous reading might well shy away from an examination calculated to show how much of the previous month’s efforts could be produced on call. Mendel’s concept of the laws of genetics was lost to the world for a generation because his publication did not reach the few who were capable of grasping and extending it; and this sort of catastrophe is undoubtedly being repeated all about us, as truly significant attainments become lost in the mass of the inconsequential.

Why the problem hasn’t been solved by now

Two centuries ago Leibnitz invented a calculating machine which embodied most of the essential features of recent keyboard devices, but it could not then come into use. The economics of the situation were against it: the labor involved in constructing it, before the days of mass production, exceeded the labor to be saved by its use, since all it could accomplish could be duplicated by sufficient use of pencil and paper. Moreover, it would have been subject to frequent breakdown, so that it could not have been depended upon; for at that time and long after, complexity and unreliability were synonymous.

Babbage, even with remarkably generous support for his time, could not produce his great arithmetical machine. His idea was sound enough, but construction and maintenance costs were then too heavy.

Had a Pharaoh been given detailed and explicit designs of an automobile, and had he understood them completely, it would have taxed the resources of his kingdom to have fashioned the thousands of parts for a single car2, and that car would have broken down on the first trip to Giza.

Machines with interchangeable parts can now be constructed with great economy of effort. In spite of much complexity, they perform reliably. Witness the humble typewriter, or the movie camera, or the automobile. Electrical contacts have ceased to stick when thoroughly understood. Note the automatic telephone exchange, which has hundred of thousands of such contacts, and yet is reliable. A spider web of metal, sealed in a thin glass container, a wire heated to brilliant glow, in short, the thermionic tube of radio sets, is made by the hundred million, tossed about in packages, plugged into sockets – and it works!

The problem is only going to get worse

So much for the manipulation of ideas and their insertion into the record. Thus far we seem to be worse off than before – for we can enormously extend the record; yet even in its present bulk we can hardly consult it. This is a much larger matter than merely the extraction of data for the purposes of scientific research; it involves the entire process by which man profits by his inheritance of acquired knowledge. The prime action of use is selection, and here we are halting indeed. There may be millions of fine thoughts, and the account of the experience on which they are based, all encased within stone walls of acceptable architectural form; but if the scholar can get at only one a week by diligent search, his syntheses are not likely to keep up with the current scene.

Part of the solution is to develop a means of sifting through the mountains of information and crunching it down into a manageable index

The real heart of the matter of selection, however, goes deeper than a lag in the adoption of mechanisms by libraries, or a lack of development of devices for their use. Our ineptitude in getting at the record is largely caused by the artificiality of systems of indexing. When data of any sort are placed in storage, they are filed alphabetically or numerically, and information is found (when it is) by tracing it down from subclass to subclass. It can be in only one place, unless duplicates are used; one has to have rules as to which path will locate it, and the rules are cumbersome. Having found one item, moreover, one has to emerge from the system and re-enter on a new path.

The human mind does not work that way. It operates by association. With one item in its grasp, it snaps instantly to the next that is suggested by the association of thoughts, in accordance with some intricate web of trails carried by the cells of the brain. It has other characteristics, of course; trails that are not frequently followed are prone to fade, items are not fully permanent, memory is transitory. Yet the
speed of action, the intricacy of trails, the detail of mental pictures, is awe-inspiring beyond all else in
nature.

Man cannot hope fully to duplicate this mental process artificially, but he certainly ought to be able to learn from it.3 In minor ways he may even improve, for his records have relative permanency. The first idea, however, to be drawn from the analogy concerns selection. Selection by association, rather than by indexing4, may yet be mechanized. One cannot hope thus to equal the speed and flexibility with which the mind follows an associative trail, but it should be possible to beat the mind decisively in regard to the permanence and clarity of the items resurrected from storage.5

From here Bush revisits an idea he posited earlier, one that I’ve omitted here for space and clarity, regarding his vision of what a future information storage and transmission system may look like. In Bush’s world, the best way to store large amounts of information was on microfilm, so naturally Bush projected that making microfilm cheaper, smaller, and more easy to use would be the course of the future. Bush calls this advanced form of microfilm a “memex” which would be analogous, the way Bush described it, to our modern-day PDAs, smart phones, laptops, and netbooks.

Implications for every day use

Most of the memex contents are purchased on microfilm ready for insertion. Books of all sorts, pictures, current periodicals, newspapers, are thus obtained and dropped into place. Business correspondence takes the same path. And there is provision for direct entry. On the top of the memex is a transparent platen. On this are placed longhand notes, photographs, memoranda, all sort of things. When one is in place, the depression of a lever causes it to be photographed onto the next blank space in a section of the memex film, dry photography being employed.

There is, of course, provision for consultation of the record by the usual scheme of indexing. If the user wishes to consult a certain book, he taps its code on the keyboard, and the title page of the book promptly appears before him, projected onto one of his viewing positions. Frequently-used codes are mnemonic, so that he seldom consults his code book; but when he does, a single tap of a key projects it for his use. Moreover, he has supplemental levers. On deflecting one of these levers to the right he runs through the book before him, each page in turn being projected at a speed which just allows a recognizing glance at each. If he deflects it further to the right, he steps through the book 10 pages at a time; still further at 100 pages at a time. Deflection to the left gives him the same control backwards.

A special button transfers him immediately to the first page of the index. Any given book of his library can thus be called up and consulted with far greater facility than if it were taken from a shelf. As he has several projection positions, he can leave one item in position while he calls up another. He can add marginal notes and comments

All this is conventional, except for the projection forward of present-day mechanisms and gadgetry.6 It affords an immediate step, however, to associative indexing, the basic idea of which is a provision whereby any item may be caused at will to select immediately and automatically another.7 This is the essential feature of the memex. The process of tying two items together is the important thing.8

When the user is building a trail, he names it, inserts the name in his code book, and taps it out on his keyboard. Before him are the two items to be joined, projected onto adjacent viewing positions. At the bottom of each there are a number of blank code spaces, and a pointer is set to indicate one of these on each item. The user taps a single key, and the items are permanently joined. In each code space appears the code word. Out of view, but also in the code space, is inserted a set of dots for photocell viewing; and on each item these dots by their positions designate the index number of the other item.

Thereafter, at any time, when one of these items is in view, the other can be instantly recalled merely by tapping a button below the corresponding code space. Moreover, when numerous items have been thus joined together to form a trail, they can be reviewed in turn, rapidly or slowly, by deflecting a lever like that used for turning the pages of a book. It is exactly as though the physical items had been gathered together to form a new book. It is more than this, for any item can be joined into numerous trails.

The owner of the memex, let us say, is interested in the origin and properties of the bow and arrow. Specifically he is studying why the short Turkish bow was apparently superior to the English long bow in the skirmishes of the Crusades. He has dozens of possibly pertinent books and articles in his memex. First he runs through an encyclopedia, finds an interesting but sketchy article, leaves it projected. Next, in a history, he finds another pertinent item, and ties the two together. Thus he goes, building a trail of many items. Occasionally he inserts a comment of his own, either linking it into the main trail or joining it by a side trail to a particular item. When it becomes evident that the elastic properties of available materials had a great deal to do with the bow, he branches off on a side trail which takes him through textbooks on elasticity and tables of physical constants. He inserts a page of longhand analysis of his own.9 Thus he builds a trail of his interest through the maze of materials available to him.

And his trails do not fade. Several years later, his talk with a friend turns to the queer ways in which a people resist innovations, even of vital interest. He has an example, in the fact that the outranged Europeans still failed to adopt the Turkish bow. In fact he has a trail on it. A touch brings up the code book. Tapping a few keys projects the head of the trail. A lever runs through it at will, stopping at interesting items, going off on side excursions. It is an interesting trail, pertinent to the discussion. So he sets a reproducer in action, photographs the whole trail out, and passes it to his friend for insertion in his own memex, there to be linked into the more general trail.

Future impact on culture

Wholly new forms of encyclopedias will appear, ready-made with a mesh of associative trails running through them, ready to be dropped into the memex and there amplified. The lawyer has at his touch the associated opinions and decisions of his whole experience, and of the experience of friends and authorities. The patent attorney has on call the millions of issued patents, with familiar trails to every point of his client’s interest. The physician, puzzled by its patient’s reactions, strikes the trail established in studying an earlier similar case, and runs rapidly through analogous case histories, with side references to the classics for the pertinent anatomy and histology. The chemist, struggling with the synthesis of an organic compound, has all the chemical literature before him in his laboratory, with trails following the analogies of compounds, and side trails to their physical and chemical behavior.

The historian, with a vast chronological account of a people, parallels it with a skip trail which stops only at the salient items, and can follow at any time contemporary trails which lead him all over civilization at a particular epoch. There is a new profession of trail blazers, those who find delight in the task of establishing useful trails through the enormous mass of the common record. The inheritance from the master becomes, not only his additions to the world’s record, but for his disciples the entire scaffolding by which they were erected.

Thus science may implement the ways in which man produces, stores, and consults the record of the race. It might be striking to outline the instrumentalities of the future more spectacularly, rather than to stick closely to the methods and elements now known and undergoing rapid development, as has been done here. Technical difficulties of all sorts have been ignored, certainly, but also ignored are means as yet unknown which may come any day to accelerate technical progress as violently as did the advent of the thermionic tube. In order that the picture may not be too commonplace, by reason of sticking to present-day patterns, it may be well to mention one such possibility, not to prophesy but merely to suggest, for prophecy based on extension of the known has substance, while prophecy founded on the unknown is only a doubly involved guess.

Conclusion

Presumably man’s spirit should be elevated if he can better review his shady past and analyze more completely and objectively his present problems. He has built a civilization so complex that he needs to mechanize his record more fully if he is to push his experiment to its logical conclusion and not merely become bogged down part way there by overtaxing his limited memory. His excursion may be more enjoyable if he can reacquire the privilege of forgetting the manifold things he does not need to have immediately at hand, with some assurance that he can find them again if they prove important.

The applications of science have built man a well-supplied house, and are teaching him to live healthily therein. They have enabled him to throw masses of people against another with cruel weapons. They may yet allow him truly to encompass the great record and to grow in the wisdom of race experience. He may perish in conflict before he learns to wield that record for his true good. Yet, in the application of science to the needs and desires of man, it would seem to be a singularly unfortunate stage at which to terminate the process, or to lose hope as to the outcome.

  1. Referring to WWII and the invention of the nuclear bomb []
  2. This is actually more an example of how statism or central planning fails to produce complex goods. For a good treatment of his subject I highly reccomend the classic essay, I, Pencil. []
  3. Even though Bush underestimated this “index of human information”, we must still admit that even with powerful indexing services such as search engines like Google, there is still a human element involved in knowing what to search for and what to do with the information returned. The index may “know all”, one day, but it cannot “see all”. A human element will always be required to make any such system useful. []
  4. I believe Bush’s prediction here is wildly undervalued in light of today’s culture. We often hear technology decried for “making people dumber” when the reality is that technology merely offsets what we need to keep in our memory. []
  5. I doubt anyone will argue with Bush on this point anymore since we now measure storage device capacity by how many copies, not what portion, of the Library of Congress they can hold. I doubt that even the most able idiot savant could rival the raw data storage capacity of the modern storage system anymore. []
  6. This has been sufficiently taken care of by digital media, specifically the world-wide web. []
  7. Modern search engines are a superb example of this. []
  8. Meaning more of our effort should be spent on recognizing the connections between bodies of information than on the details of the information itself. []
  9. Here Bush describes what has effectively been realized by user-generated content tomes such as Wikipedia. []

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Fred Brooks on the promise of object oriented programming

One view of object-oriented programming is that it is a discipline that enforces modularity and clean interfaces. A second view emphasizes encapsulation, the fact that one cannot see, much less design, the inner structure of the pieces. Another view emphasizes inheritance, with its concomitant hierarchical structure of classes, with virtual functions. Yet another view emphasizes strong abstract data-typing, with its assurance that a particular data-type will be manipulated only by operations proper to it.

Now any of these disciplines can be had without taking the whole Smalltalk or C++ package—many of them predated object-oriented technology. The attractiveness of object-oriented approach is that of a multivitamin pill: in one fell swoop (that is, programmer retraining), one gets them all. It is a very promising concept.

Why has object-oriented technique grown slowly? In the nine years since “NSB,” the expectancy has steadily grown. Why has growth been slow? Theories abound. James Coggins, author for four years of the column, “The Best of comp.lang.c++ ” in The C++ Report, offers this explanation:

The problem is that programmers in O-O have been experimenting in incestuous applications and aiming low in abstraction, instead of high. For example, they have been building classes such as linked-list or set instead of classes such as user-interface or radiation beam or finite-element model. Unfortunately the self-same strong type checking in C++ that helps programmers to avoid errors also makes it hard to build big things out of little ones.

He goes back to the basic software problem, and argues that one way to address unmet software needs is to increase the size of the intelligent workforce by enabling and coopting our clients. This argues for top-down design:

we design large-grained classes that address concepts our clients are already working with, they can understand and question the design as it grows, and they can cooperate in the design of test cases. My ophthalmology collaborators don’t care about stacks; they do care about Legendre polynomial shape descriptions of corneas. Small encapsulations yield small benefits.

David Parnas, whose paper was one of the origins of object-oriented concepts, sees the matter differently. He writes me:

The answer is simple. It is because [O-O] has been tied to a variety of complex languages. Instead of teaching people that O-O is a type of design, and giving them design principles, people have taught that O-O is the use of a particular tool. We can write good or bad programs with any tool. Unless we teach people how to design, the languages matter very little. The result is that people do bad designs with these languages and get very little value from them. If the value is small, it won’t catch on.

-Fred Brooks, The Mythical Man-Month, pg. 220

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What to look for in a new computer

I’ve been asked by friends and family several times recently what to look for when looking for a new computer. Regardless whether you are looking for a laptop or desktop I believe there are a few guidelines that will help aid you in making your next computer purchase.

The key things to look for in a computer are:
Whatever system you choose, I would also encourage you to keep in mind the cost of replacing it. Not upgrading or repairing it, but completely replacing it. Practically this means that if you are going to choose between a $1200 system and a $600 system and the features are roughly the same (or even close) then I would take the $600 one.
As for software, specifically in regards to data security, I would recommended that you setup a Dropbox account and store your critical data there. This would allow you to backup and distribute the file automatically across multiple locations (including cell phones). If not Dropbox, then another cloud-storage service, but I’ve found Dropbox to be the best. Storing your critical data on a cloud-based storage system also makes replacing your system later a lot easier.
Happy hunting!