Saturday, July 09, 2011

Object Thinking is the natural way to think. Introduction

I don't know why I'm up so early on a Saturday, but I am. *yawn*. So I've been writing a paper reviewing other texts, to explain why Object Thinking is the natural way to think.
I am doing this because I do not want to lose an internet argument. I know. I've already lost. Both side have. That's how internet arguments work.
The argument is at Programmers, particularly my answer to the question "is OOP hard because it is not natural?" SK-Logic is zealously anti OO, and I am equally zealously pro OO.
Then the other day I was discussing what I'm writing with Pierre 303, in the Programmers' chat room, and he suggested that I make it into several 'blog articles, because then it would be easier to digest. I agree, so that's what I'm doing. I still don't know why I'm up so early, but at least I'm doing something.

Object Thinking; it's been around for decades as a paradigm for software design, but what is it? When presented with a problem, someone using object thinking will start to decompose the problem into discrete sections that can interact with each other. You could, for example, be forced to change the tyre on your car. A simple task, certainly, but to do it you must understand the tools and relevant components of your car, and how they need to work together to achieve your goal.

It might take several attempts to achieve a fine grained enough understanding to effectively solve the problem. Your first pass at the above example might leave you with the idea to take the wheel off your car. A second thinking might make you realise that you need to lift the car off the floor to do that, and so on.

One thing that can give you a head start in solving a problem using object thinking is background knowledge. Knowing about your problem domain, what the objects in it are capable of, makes it easier to plan how to use them. Not knowing enough can cause issues, however, if assumptions are made based on incomplete knowledge.

For example: You are asked to stick a poster to the wall, without leaving holes in the wall. You are given a hamster, newspaper and some Blu Tack®, along with the poster. If you don't know what Blu Tack® is for then your understanding of the problem domain is incomplete and you could end up using the hamster to chew up newspaper into balls, and use those to stick the poster to the wall.

It is also important to note that not everything present in your problem domain will necessarily be used to solve the problem. So, in the previous example, you might not use the newspaper or hamster at all (or, of course, you might find the hamster solution better, as it reuses the newspaper, which is more ecological).

So how does this apply to software design? Software is just “algorithms and data structures”, right? Well, at the end maybe, but you've still got to design it. Software is the output of people's attempt to solve a problem. Solving a problem with object thinking is the natural way, as this series of posts hopes to demonstrate, because it uses people's natural problem solving techniques.

Object thinking is a core tenet of Object Oriented Design (OOD), a well known software design paradigm. The inventors of OOD set out to fix what they saw are the main problem with software design – software design was taught to make people think like computers, so that they could write software for computers.
A book that extensively covers the meaning and practical aspects of object thinking is Object Thinking by David West (2004, Microsoft Press). In it he likens the way that traditional programmers use OOD to writing lots of small COBOL programmes [1]. Objects in this sense have been turned into data structures with algorithms wrapped around them. While modularising code is better than having one large function, it only makes designing software a little easier. It still focuses the attention of the design on how a computer works and not how the problem should be solved.

So what makes reasoning about large systems easier? Focusing on the problem space and decomposing it into several smaller problems helps. But what is easier to think about? Is it easier to think how those problems translate into code? Perhaps in the short term, but you will end up solving the same problems over and over again, and your code will probably be inflexible.

Would it be better to think about software design the same way you think about solid world problems? That way you can use your innate problem solving skills to frame and express your design.

It turns out that the way people reason about real world problems is to break them down into smaller parts, using their background understanding of the problem space, take the parts of the problem space and treat them as objects that can do things and have things done to them, and find way for the objects to interact. [2]

This works well because people like to anthropomorphise objects, so that they can imagine the object doing things under its own agency, even if in the end it's a person causing the action.[3]

How can you be sure this is how you think, and is therefore the more sensible way to approach software design? Well it turns out that there is an oft ignored backwater science known as Cognitive Psychology, and scientists in this field have been studying people for decades, to find out how they work.

Future posts in this series will review certain cognitive psychology and neuropsychology texts and expand on how this applies to object thinking. The end goal is to demonstrate that object thinking is innate and therefore the best strategy for designing software.

Next post in the series: Object Thinking - Objects: a neurological basis

[1] Object Thinking, D. West (2004, Microsoft Press) p9
[2] Problem Solving from an Evolutionary Perspective visited 9th July 2011
[3] Object Thinking, D. West (2004, Microsoft Press) p101

Blu-Tack is a registered trademark of Bostik. I am not affiliated with Bostik.