Speaking My Mind

I have long been frustrated with all the different text mark up languages and word processors that I have used. There are many reasons for this; but the biggest issue is that markups (including very powerful ones like TeX) are not targeted at the kind of stuff I write. Nowadays, it seems archaic to still be thinking in terms of sections and chapters. The world is linked and that applies to the kind of technical writing that I do. I believe that the issue is fundamental. A concept like "section" is inherently about the structure of a document. But, what I want to focus on are concepts like "example", "definition", and "function type". A second problem is that, in a complex environment, the range of documentation that is available to an individual reader is actually composed of multiple sources. Javadoc exemplifies this: an individual library may be documented using Javadoc into a single HTML tree. However, most programmers require access to multip...

Sometimes a restriction in a programming language makes sense and no sense at all — all at the same time. Modeling the real world Think about the Java restrictions on the modeling of classes: a given class can only have one supertype and a given object's class is fixed for its lifetime. From a programming language perspective these restrictions make a good deal of sense: all kinds of ambiguities are possible with multiple inheritance and the very idea of allowing an object to be 'rebased' fills the compiler writer with horror. (Though SmallTalk allows it.) The problem is that, in real life, these things do happen. A 'natural' domain model is quite likely to come up with situations involving multiple inheritance and dynamic rebasing. For example, a person can go from being a customer, to an employee, to a manager to being retired. A given person might be both an employee and a customer simultaneously (someone else may not be). Given a domain that is as flexible as th...

In the early 1980's Bob Kowalski made famous an interesting equation: Program = Logic + Control. The idea of that equation was that programming was essentially a combination of logic -- i.e., what you wanted done -- with algorithm -- how you wanted it done. It is a fairly commonplace fact that any non-trivial program has a similar flavor to it: there is often a substantial amount of machinery that is used to deliver the value in the program; together with some form of policy statement/expression that governs the precise requirements for a particular execution of the program. The larger the program, the more obvious it is that there is this layering into mechanisms and policies. For example, one could argue that a word processor's mechanisms are all the pieces need to implement text editing, formatting and so on. If the word processor supports styles, especially named styles, then these styles are a simple form of policy. At larger scales, when considering networked applications...

Here is an interesting intuition: the key to liberating software development is to use programming languages that are not, by themselves, turing-complete. That means no loops, no recursion 'in-language'. Why? Two reasons: any program that is subject to the halting problem is inherently unknowable: in general, the only way to know what a turing-complete program means is to run it. This puts very strong limitations on the combinatorics of turing-complete programs and also on the kinds of support tooling that can be provided: effectively, a debugger is about the best that you can do with any reasonable effort. On the other hand, a sub-turing language is also 'decidable'. That means it is possible to predict what it means; and paradoxically, a lot easier to provide a rich environment for it etc. etc. An interesting example of two languages on easier side of the turing fence are TeX and CSS. Both are designed for specifying the layout of text, TeX is turing complete and CSS ...

Some time ago I was involved in a running debate about whether we should be using Ruby on Rails rather than the Java stack (junkyard?) that we were using. At the time, I did not really participate in the discussion except to note that everything seemed to be at least 5 times too difficult. I had this strong intuition that there were so many moving parts that that was the problem. The application itself was not really that hard. My assertions really ticked some of my colleagues off; for which I apologize; sort of. I guess that I come from a tradition of high-level programming languages, by high level, I would say that I would consider LISP to be a medium level language, and Prolog is slightly better. I would say that it is a pretty common theme of my career that I end up having to defend the position of using high-level tools. I have gotten a number of arguments, ranging from "it will not be efficient enough" to "how do you expect to find enough XX programmers?". I u...

Rodney Brooks once wrote that robots would be human when treating them as though they were human was the most efficient way of interacting with them. (Not a precise quote.) This is an interesting variation on the Turing test. It assumes that we decide the smartness of machines in the context of frequent interactions with them. It also builds on an interesting idea: that in order to deal with another entity, be it human, animal or mineral, we naturally build an internal model of the entity: how it behaves, what it can do, how it is likely to react to stimuli etc. That model exists for all entities that we interact with; a rock is not likely to kick you back, your word processor will likely crash before you can save the document etc. When the most effective way to predict the behavior of a machine is to assume that it has similar internal structure to ourselves, then it will, for all intents and purposes, be human. So, here is another thought: how do we know that another human is human?...

I am probably not alone in visualizing Turing's Universal Machine as a little animacule walking over a linear landscape of ones and zeros: The great innovation of thinkers such as Turing and others was to reduce the complex world of algorithms and functions into something simple and elemental: all computable functions can be thought of as state machines operating over a large collection of ones and zeros, presence and absence. There are arguably many differences between a Turing Universal Machine and a modern browser (quite apart from the fact that, being a Javascript interpreter makes a browser a TUM). But for me, one of the most striking differences is that where a TUM is an animacule in a universe of one and zeroes, the browser is an animacule in a universe of HTML , CSS , HTTP and so on. The browser understands a different world than Turing's computer. Were we to draw a browser as an animacule, it should look like: There are similarities, and if you were to look at it fro...

I have previously wondered out loud what ontologies are good for. I now believe that one of the most powerful use cases for semantic technology lies in social networking applications; and matching in general. By social networking I mean "putting people in touch with each other"; especially in situations that are inherently asymmetric. For example, putting potential volunteers in touch with people who could use their services; putting buyers in touch with sellers, and so on. The reason is simple: the language spoken by the two sides is inherently different: a seller or volunteer knows a lot (or maybe not) about what he or she can do or would like to do. But a consumer often does not know to translate his or her problem into a solution that the provider can offer. Put more graphically, providers speak features, and consumers speak problems. This is even if they can find each other. In the middle, there is an opportunity for someone to put the two together. A match maker has to...

I am sure that everyone who has ever dabbled in the area of Ontology has been asked that question. Personally, I have never heard a truly convincing response; even though I strongly feel that Ontologies are quite important. I recently listened to a radio segment in which someone in Algeria (I think) was complaining about the new law that required all teaching to be done in Arabic. It seems that most university-level education is in French, and that many parents try to send their kids to schools that teach in French. The issue was that Arabic simply does not have the vocabulary demanded by a modern high-tech education. Arabic is not alone in this dilemma: French itself is littered with Les mots Anglais; and English is a true hodge-podge of Anglo-Saxon, French, German, Hindu, Japanese, and many other languages. It often happens that when a culture acquires a set of concepts, it does so in the language of the originators of those concepts. It is often considerably easier to import wholes...

Someone recently asked me why I was working on the particular topics that I was interested in. I am afraid that in the heat of the moment I had a reasonable but ultimately lame answer (something about reducing friction in the marketplace). In fact, the true answer is simpler and much more powerful. I want to be part of a 'professional' industry, and I believe that we are not really there yet. It is a constant source of amazement to me that there have not been any class action lawsuits against certain high profile software companies. I like the phrase safe and effective , which describes the basic requirements for medicines of course, but should be equally applicable to software. What would the benefits of being able to label a system safe and effective? Primarily it means that someone using the system has some assurance that the software will do what it is supposed to do, and that it wont lead you into trouble. Of course, if you take too many aspirin, or if you misuse a softwar...

When someone says something to the effect “We will add Semantics and all your problems will be solved” the image that that conjures up for me is salt: “Let us sprinkle some Semantics and it will taste better”. And, yes, somehow, Semantics always seems to be capitalized. Needless to say, I do not buy this for a couple of reasons: Everything has some kind of semantics. It just may not be all that useful. Any explicit representation of the semantic relationships becomes syntactical. Processing therefore becomes processing of structures; you are still writing regular code to do that processing. There is no such thing as two people or agents having the same interpretation of a term. Oops, there goes all that Ontology stuff :) What a chair means to me is overlapping, but different to what it means to you. Even for me, the meaning depends on what I am trying to do (arrange them for dinner, sit on one, ship it and so on.). Luckily, agreement on the meaning of a term is neither poss...