On the Internet, I frequently see terms misapplied to other contexts. Whether its a basic definition misapplied to a different realm, or an analogy grossly misapplied to a context that is not in fact similar. Since this particular term ‘conceptual integrity’ however was used as a beating stick on Pylons, I felt it’s something worth discussing.
First, its very useful to actually understand the context of the book the term comes from, The Mythical Man-Month. The Mythical Man-Month is about Fred Brooks observations as a manager on the OS/360 project at IBM, and the problems encountered when developing an OS for end-users. Before getting into the question of whether an OS end-user is equivalent to a web framework end-user, its useful to look at the term being referred to, ‘conceptual integrity’.
Wikipedia has a fairly good summary of the term:
To make a user-friendly system, the system must have conceptual integrity, which can only be achieved by separating architecture from implementation. A single chief architect (or a small number of architects), acting on the user’s behalf, decides what goes in the system and what stays out. A “super cool” idea by someone may not be included if it does not fit seamlessly with the overall system design. In fact, to ensure a user-friendly system, a system may deliberately provide fewer features than it is capable of. The point is that if a system is too complicated to use, then many of its features will go unused because no one has the time to learn how to use them.
Is there Conceptual Integrity?
The Pylons developers, including myself, spend quite a bit of time deciding what goes into Pylons, and what does not. Pylons is in fact very very small at its core due to our refusal to let ‘stuff’ into Pylons that is outside its strictly defined scope. In fact, a great many comments I get are usually about features people want, but that aren’t in the scope of Pylons to provide. I would argue that this does show thought has gone into ‘conceptual integrity’, in the explicit decisions made about what is and isn’t provided.
The scope of Pylons is to provide a small, concise, WSGI-driven, lightweight framework, that provides the flexibility for a web developer to use the best tools for the job at hand for building their web application. I would argue based on the definition, the goal of Pylons, and what Pylons has in it now, that it fully meets the design goal of having conceptual integrity with regards to feature scope.
While the original blog post I cited above starts with conceptual integrity, it delves deeply into framework design issues like, ‘Should a framework pick the ORM for you?’. This is slightly odd in the context of Pylons, as the default ORM, and template language are chosen, Pylons merely emphasizes that the choice is yours should you wish to change it (as does Django).
In another misapplied analogy, a parallel is drawn up between having an opinion on a writing style, to having an opinion on a library. Consider how odd this analogy is, that the fairly minor effect of adding a trailing ‘S’, should be compared to whether a particular ORM library is capable of meeting your demands. Should the framework authors decide whether the ORM meets your demands? Should the framework lose a significant amount of capability the second its stock ORM fails to handle your needs? These are interesting questions, well beyond an attempt to draw a parallel to adding a trailing ‘S’ to a word.
Since its clear that Pylons doesn’t encroach on conceptual integrity regarding features that are unused, the next aspect to look at is the concept of a ‘user-friendly system’. This becomes a little more difficult to analyze, because it brings into question the expectations one has of the ‘user-base’. It also shows how the original term of conceptual integrity was misapplied as another parallel is drawn, this time one that I think all web developers should be somewhat terrified by.
Website end-user == Website Programmer?
The last parallel, is to compare the programming expertise of a web developer, to the internet naivety of the website end-user. (Does that offend any other web developers?) The latter of which is well documented in various web usability books, such as the “Don’t Make Me Think” book. The underlying concept being:
- Website users have short attention spans
- Website users won’t use a website that requires thinking
- Website users have no patience
The thesis of this parallel is that a framework author is somehow in the superior position of knowing the appropriate library that will work for your task, and should therefore decide the tools for you. The parallel applied looks like:
- Website programmers have short attention spans (ok, I somewhat buy this one :)
- Website programmers won’t think about whether the tools at hand will accomplish their task
- Website programmers have no patience (Given the languages you have to learn to do anything, I seriously doubt this)
Now, there are quite a few website programmers that don’t think about whether the tools they use, work best for their task. I have seen many websites that are slow, inefficient, or just not well designed because of a lack of thinking regarding architecture, and tool choices. I would not consider these to be website programmers I would want to work with, nor are they the target audience or ‘end-user’ of Pylons. The door is purposely left open in Pylons, and lit up, with the choice available in libraries to use with Pylons.
Regarding making decisions, Pylons has choices for all the same components as Django has decided on:
The main problem apparently being, Pylons has emphasized that there is choice, that the framework is built so that they could be swapped, should one of these not be the best tool for your web application.
The Pilot System
When designing a new kind of system, a team will design a throw-away system (whether it intends to or not). This system acts as a pilot plant that reveals techniques that will subsequently cause a complete redesign of the system. This second smarter system should be the one delivered to the customer, since delivery of the pilot system would cause nothing but agony to the customer, and possibly ruin the system’s reputation and maybe even the company’s.
In response to the original post regarding conceptual integrity, I submit the issue of the pilot system. Django and other frameworks that start off with libraries you didn’t analyze in regards to your particular web application, have more than a few times led to pilot systems (I usually hear about the second incarnation, which was then done on Pylons).
Where you realize later down the road, “wow, this ORM just can’t handle the data model I have”, which then leads to, “well, since the ORM was hooked into the XML serializer, the admin UI, the form generator, etc. there’s now no competitive advantage over Pylons… which didn’t have those extras.” Systems with heavy and deep integration of libraries that may or may not meet your demands, where large parts of the system become relatively useless should you stop using one part of it, are extremely prone to being a pilot system.
When your pilot system is done, I invite you to check out Pylons, and think about what is going to work for your website application.
Please note that I take deliberate care in referring to Pylons for use with developing web applications, its my belief that Django, and similar systems in other languages with an ‘app’ centric approach like Joomla, Drupal, etc. are excellent for making web sites. While you can easily make websites with Pylons apps, this is definitely not the primary use-case emphasized and designed for, so it is harder and less obvious in many respects than Django.
The other thing everyone should’ve learned from these posts, is that The Mythical Man-Month is a rather good book worth reading. ;)