Tuesday, March 14, 2017

Navigation

The primary goal of software is to be useful. In order to do that, someone with a problem needs to use it to build up a ‘context’ and then execute some functionality. This context can be seen as all of the inputs necessary for their computation, whether it is persistent data, current configuration or the results of navigating from a broader context down to a specific one.

As an example of that latter input, for a GUI application, a user might start the program and select a number of menu items and buttons that gradually get them closer and closer to being able to run the desired code. They might open a file, move the cursor to a specific line, then enter some text. When satisfied, they will finally save the document, as a file, for long-term persistence on a disk or flash drive somewhere, achieving their goal.

The functionality that they require is really to modify an existing persistent file of a given format. Everything else they have to do, starting the app, picking file, changing it, etc. is just building up a context of inputs so that the save happens in the way they expect it to. Consequently, if the editor dies before the file is saved then they have to go back and navigate through the context again. It’s not over until the final functionality is completed.

For a command line environment it is the same. Most often the user works their way into a directory, might change the file with something like sed or awk redirected into a temp file, and then copies the modified file on top of the old one. Their navigation through the various commands is nearly equivalent to utilizing a series of widgets in a GUI.

In that sense we can frame any user action with a computer as a long series of navigating down to specific contexts to fire off some code. Programmers often focus on what that code is, and how it works, but from a user’s perspective the ease or pain of navigating is what they really see.

When programs are small, the amount of functionality is small enough that it can be pushed up to the top level. It really doesn’t need any serious organization. But as development continues and more and more functionality becomes available, knowing some functionality exists and navigating to it become larger and larger problems. In many active but ancient products, a great deal of the features just aren’t used because they are nearly impossible to find when needed. They exist, but they are buried in unexpected places.

To counter this, the focus should change as the code grows, first as needing new functionality, then it switches over to finding ways to reorganize the interface so that all of that existing functionality is still usable. This of course involves heavy refactoring, which is hugely expensive as the underlying layers of code have become locked into position, so it is rarely done.

It is also extremely difficult, in that the designers need to re-imagine every aspect of the program from the top down, from the perspective of the user. And then they need to overlay an organizational philosophy on top of everything so that it is clearly intuitive to most people on where to navigate to achieve their goals. There isn’t, that I know of, some magical means of applying ‘normalization’ such that it makes this process mechanical, and whatever arrangement they come up with will eventually degrade as the functionality continues to grow. It’s a perpetual problem.

What seems to occur in practice is that the programs just gradually decay until they are essentially stuck. The navigation becomes so bad, and arbitrary, and the work to fix it is so large, that almost no more forward progress is made. Generally this is followed by another program from someone else, with a different organizational perspective getting written and taking away most of the users. Eventually that one stalls too, and the cycle repeats itself. In that way it may seem like we are progressing, but often the case is that the replacements simply ignore old, but required functionality, which when added hastens the inevitable outcome. These days it seems more like we are just going round and round in circles.

It is far easier to ignore the navigation and just focus on grinding out functionality, which is why it is common practice. When software was young, this approach made a lot of sense, in that there was a real need for new features. But most of the industry has matured now, and there is a plethora of functionality available for just about every imaginable computation. It’s no longer an issue of having to create the functionality, rather it has become one of trying to find it. This change does not seem to be reflected in our development cultures. Yet.