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I am Joannes Vermorel, founder at Lokad. I am also an engineer from the Corps des Mines who initially graduated from the ENS.

I have been passionate about computer science, software matters and data mining for almost two decades. (RSS - ATOM)

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Tuesday
Oct102006

## Wiki misuses (collaborative tools, part 1)

Great software development requires great tools; but tools do very little in themselves if the craftsman lacks the proper skills. In my (limited) experience, I have noticed that collaborative tools are often extremely useful (i.e. provide strong productivity boosts) while also being quite hard to master.

There are far too many collaborative tools to discuss for a single blog post; I will start with the wikis.

### Why do you need a wiki?

There are many other ways to communicate and information within a development team, namely person to person talk, email conversations, source code comments, discussion boards, blogs, instant messengers, phone calls ... and the list goes on. There is no magic in wikis; they won't be a substitute for all that.

Let's start with some wiki misuses, i.e. the kind of things that does not work very well with wikis. I am not saying that it is not possible to use a wiki in the situations listed below (it always "possible"); but I feel that those situations are simply ill-adapted to be handled by wikis.

### Wiki-based documentations are poor documentations (probability = high)

A wiki is not a substitute for proper reference documentation. In this domain, two of my poorest user experience while trying to get some reference documentation were the WordPress wiki and the JotSpot wiki although I am quite a fan of those two products. What's the problem here? Well, quite simply there is simply no reason for the consumer to contribute to the reference documentation (I say "consumer" to refer to whoever is consuming the documentation). Therefore, do not expect any interaction at that such level.

As a secondary point, it can also be argued that a reference documentation requires to be highly structured usually following closely the source code design itself); otherwise it's just a pain to navigate through. Wikis do not encourage (nor provide any automated mechanisms) to support such structures. In this respect, one of best software documentation that I have ever encountered is the ZeroC Ice documentation (but I am moving away from the topic of this post).

### Wikis aren't that good for open diffusion (probability = high)

I know that Wikipedia is living counter-example of the title of this section. Yet, wikis are on average quite inappropriate for open diffusion. When I say open, I mean referring to a wiki that is not restricted to the development team.

A primary issue with wiki is that they aren't that much appealing in terms of layout and navigation. Yes, it is possible to customize the appearance and the navigation system of a wiki, but by doing so, you're going back to regular website development. The Math.Net open-source project is quite illustrative in this matter. Have a look at the Math.Net project page vs. the Math.Net wiki. Which one of those two pages looks better in your opinion? OK, I know you're not going to look at those pages, so just trust me.

A second issue with wiki is that the information is usually rougher and less structured compared to classic "static" page. This point is not an issue in itself, enabling some kind of fuzzy teamwork is actually one of the main benefits of the wiki. Yet your wiki is likely to act as information pollution for the occasional visitor.

The last issue with open wikis is that they are putting boldness requirements quite high. Indeed, a main challenge with wikis is to get people involved. This point is true for almost every collaborative tool. Self-confidence is one of the strongest hindering factors when it comes to wiki writing. By opening your wiki, you are putting quite a lot of pressure on your potential contributors compared to the internal wiki situation.

More on Good wiki management soon, stay tuned...

Friday
Oct062006

## Typo hunting: get some weapons first!

It's just too hard to spell check your text by hand (or it requires an unreasonable amount of time). Before you actually get a spell checker, you might not even realize how many typos you produce. I have just downloaded today the FireFox RC1 that includes a web form spell checker. My first target for typo hunting was an intranet wiki I am working on. I feel that I won't ever go back to a browser that does not provide such a feature natively.

My second target for typo hunting was the source code of a Asp.Net application I am currently developing. Since Visual Studio 2005 does not provide a native spell checker (shame! such feature should have been implemented years ago), I have used the MailFrame CodeSpell product. CodeSpell has a really nice VS 2005 integration. On the minus side, the dictionary is a bit light at the present time (nchar or aspx not being part of the default dictionary for example) and I did experience of a few crashes while playing with the custom user dictionary.

A funny aspect of applying this source code spell-checker was to discover that 3rd party [*] XML documentations present in my .Net solution were no less typo-crippled than my own code. If automated spell-checking is not part of your development process, well, it should.

[*] Elmah and Telerik are both advised to get some spell-checking tools :-)

Tuesday
Oct032006

## The unteachable parts of software engineering

Having the responsibility to handle the software engineering course at the ENS in spring 2007, I have started to think about the desirable qualities that make the difference between an average developer and a brilliant one. Indeed, I can't think of a better goal for this course but to actually try to develop such qualities.

### What makes a "good" software developer?

It's an obvious fact that many qualities and skills are required to make a good developer. Smart and Get things done are often cited as the top criterions to decide whether a candidate should be recruited or not.

... a passionate curiosity for software related matter ...

I would complete those two criterions with a third one that I consider to be no less important: a passionate curiosity for software-related matters. Most well-known antipatterns such as programming by permutation, golden hammering, re-inventing the wheel, ... are caused by a lack of curiosity. There is far too much to know of the subject of software engineering to trust any particular school diploma (or certification) to be sufficient to produce even a "passable" developer.

Additionally, the software world is fast-paced. Hardware and software get obsolete alike. Development methods evolve. Better tools are released continuously. The sheer (intellectual) complexity of those evolutions is beyond what a single individual can possibly handle. Curiosity when leveraged through teamwork is a strong driver to actually maintain the development practices and tools as close as possible to a state-of-the-art level.

Finally, on the long run, I do not see how it is possible to stay motivated (and therefore productive) if there is no eager interest in mastering this constant flow of evolutions.

### How to train such a developer?

I have listed smart, get things done and passionate curiosity as being the top qualities for a software engineer. But this list is more than troublesome for a teacher: it's not even clear whether any of those qualities can be actually taught

Concerning the first criterion, i.e. smart, I have simply surrendered all "academic" ambitions. The course schedule is far too short; beside I have the chance of having ENS students who are already very smart (though entrance exams have already filtered out students who were not so smart). Yet, the course can them the opportunity to apply their intelligence to a large variety of fuzzy problems that are inherent to software development.

The second criterion get things done is probably the most actionable element of the three. The French education system (highly selective and highly individualistic) usually produces people that are relatively weak against this criterion, the ENS students being no exception (quite the opposite in fact). I have planned to incorporate a student software project within the course mostly to push student develop a get things done mentality .

As for the first criterion, I haven't much ambition to actually transmit a passionate curiosity the students. In this respect, my first ambition will be to avoid the issue that usually plagues software engineering courses: an overwhelming boredom. I do not think it is really possible to create curiosity ex-nihilo if people have no interest beforehand. But, assuming that students are at least somehow interested (well, if not, it's going to be tough for the students and me alike), an "expand your horizons" strategy for the course might give them materials to apply and develop their curiosities.

There are two kinds of students: those who are too weak to be taught anything and those who are so strong that the teacher is totally unnecessary.

Bottom-line: out of three main qualities to make a good developer, the ambitions associated with the software engineering course I am thinking of are pretty weak. Well, considering the importance of the subject, I still believe it's a worthy attempt (stay tuned, more on later posts ... )

Sunday
Sep242006

The 30-years-old unix pattern for user management involves a UserName, Password pair associated to a unicity constraint on the usernames. On most web applications, this pattern has been enriched as a triplet UserName, Password, Email with, usually, a two-fold unicity constraint both on usernames and on emails. But is there any good reason to distinguish e-mail from username?

By looking at the major web players (Google, PayPal, Amazon ...), the answer is negative without any doubt. This pattern has already been widely adopted. Yet, it's still not stated a being an obvious web design best practice. For example, there is still no simple ways in ASP.Net 2.0 to enforce such a policy through the CreateUserWizard. Let's review the arguments in favor of this pattern.

• UserName and Email are redundant because both are used as user identification keys. For the user, it means more information to provide at the registration step, and then more information to remember.

• Choosing your UserName is often painful because most of the time your favorite username is already taken (unless you got the chance having a pretty unfrequent first name like joannes).

A mighty, but somehow recursive, argument is that since big players (Google, PayPal, Amazon) are doing that then doing anything else is only going to hurt a large number of users.

The only real drawback of this approach is the lack-of-privacy concern i.e. you may prefer your e-mail address to stay invisible to the other users of the website where you are registering. Yet IMO, the Display Name is a much more appealing and user-friendly concept compared to the username approach.

Ps: PeopleWords.com does not follow this pattern. I have no good excuse for this situation. I was just young and inexperienced at the time.

Saturday
Sep232006

## Antipatterns of Software engineering courses

I am very honored to be in charge of the Sofware engineering and distributed applications course at the Ecole normale superieure (ENS). This will be my first official teaching assignment, and I will be affected to brilliant Licence 3 students (it's pretty tough to get through the entrance exam of the ENS).

Software engineering is a difficult topic to teach. I have been browsing the web just to have an outlook at what people are usually doing in a software engineering course, and I must confess that I haven't found anything very satisfying so far (although the MIT experience is definitively worth reading). In a nutshell, I would say that software engineering is the art of producing great software with limited resources. In respect to this definition, it seems that there are many ways to spend hours teaching things that totally miss the point. I have listed in this post what I think to be the 3 most common ways of disgusting students from all software engineering matters.

### Coding antipattern

Here is the 300-pages API. This API will be the subject of your exam. Documents will not be authorized.

The second fastest way on earth to get your 30h of teaching ready is simply to teach some particular programming language and its associated technologies (think Apache/PHP/MySql, stay tuned the fastest way will be detailed next). Just take any reference documentation, and you get enough material to talk for 30h. But your course is both deadly boring and super-short-lived. Some people assume that their students have no prior knowledge about any language. I won't (it's stated in the course-prerequisite btw). My objective is not to teach the syntax of any programming language, because I believe students are smart enough to learn that by themselves. If not then, I would say that it was a bad move to take the software engineering course in the first place.

### ISO-certified development antipattern

If you don't assess your customer requirements through a 17-phase process, then you're not ISO-171717.

Just by looking at Learning Tree - Software Engineering course (one of the top result of Google for "software engineering"), I think Wow, those people are attempting to kill their attendants with boredom. Look at the table of content: Life cycle phase contains (sic) 1) Understanding the problem 2) Developing the solution 3) Verifying the product 4) Maintaining the system. I can't remember of any software project that ever happened that way but who cares because the content is going to be nothing more than obvious statements anyway.

I call this kind of teaching ISO-certified development, the worst part being certainly the enumeration of software life-cycle models (which are, according to Learning Tree: Waterfall, V, Phased, Evolutionary and Spiral). This approach is basically the extreme opposite of the coding course. You're not teaching anything technical, instead you end-up with long, super-detailed, over-boring descriptions of business practices that do not even exists as such in the real world anyway.

### Green-field projects antipattern

Our project was to develop a video game. Alice wrote the scenario, Bob took care of the rules and I did the graphics. The rest has been left unfinished.

The fastest way on earth to get your 30h software teaching course ready is the green-field project: just say Decide among yourselves what you're gonna do, I will be the judge of the software you produced and then, spend the next 30h doing groupwork (groupwork is like teamwork but instead of having a team, you have a random bunch of people, i.e. a group). Don't take me wrong, I think that projects do have a huge pedagogic value, yet the probability of re-discovering good software engineering ideas just by doing random groupwork is low.

There are also other criticisms to the green-field projects as usually practiced. The first poor practice is to let the students come up with their own project ideas. For various reasons, students have a tendency to favor projects that are quite ill-adapted (such as video games); then it's really hard to scale the project in such a way that it matches the time to be invested in the course. The second poor practice is to let the students come up with their own internal organization. I have never encountered any company where all employees are equal, I do not see why it should be the case in a student software project (more on the subject in a subsequent post).

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