Everything should be made as simple as possible, but not simpler. When I am working on a problem I never thing about the beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong. If you can't explain something to a six-year-old, you really don't understand it yourself. If I had asked people what they wanted, they would have said faster horses. If the user can't use it, it doesn't work. If the user can't find it, it doesn't exist. If there's a 'trick' to it, the UI is broken. Nearly all men can stand adversity, but if you want to test a man's character, give him power. In an ideal world, every system could run instantly, consume zero storage space, use zero network bandwidth, never contain any errors, and cost nothing to build. In the real world, a key part of the designer's job is to weigh competing design characteristics and strike a balance among those characteristics. There are two ways of constructing a software design: one way is to make it so simple that there are obviously no deficiencies, and the other is to make it so complicated that there are no obvious deficiencies. Three years from now, no one will remember if you shipped an awesome software release a few months late. What customers will still remember three years from now is if you shipped a software release that wasn't ready a few months too soon. The methodology used should be based on choice of the latest and best, and not based on ignorance. It should also be laced liberally with the old and dependable. You know you have achieved perfection in design, not when there is nothing more to add, but when there is nothing more to take away. We must not forget that the wheel is reinvented so often because it is a very good idea; I've learned to worry more about the soundness of ideas that were invented only once. The most difficult part of requirements gathering is not the act of recording what the users want; it is the exploratory, developmental activity of helping users figure out what they want. Just because nobody complains doesn't mean all parachutes are perfect. It's OK to figure out murder mysteries, but you shouldn't need to figure out code. You should be able to read it. Any darn fool can make something complex; it takes a genius to make something simple. Programmers over the lifetime of a system spend far more time reading code than writing code. The greatest challenge to any thinker is stating the problem in a way that will allow a solution. The signature of mediocrity is not the inability to change, it's chronic inconsistency. The difference between a good and a poor architect is that the poor architect succumbs to every temptation and the good one resists it. Fools ignore complexity; pragmatists suffer it; experts avoid it; geniuses remove it. Simplifications have had a much greater long-range scientific impact than individual feats of ingenuity. The opportunity for simplification is very encouraging, because in all examples that come to mind the simple and elegant systems tend to be easier and faster to design and get right, more efficient in execution, and much more reliable than the more contrived contraptions that have to be debugged into some degree of acceptability... Simplicity and elegance are unpopular because they require hard work and discipline to achieve and education to be appreciated. Computer Science is the only discipline in which we view adding a new wing to a building as being maintenance. Architect: Someone who knows the difference between that which could be done and that which should be done. The ability to simplify means to eliminate the unnecessary so that the necessary may speak. If our designs are failing due to the constant rain of changing requirements, it is our designs that are at fault. We must somehow find a way to make our designs resilient to such changes and protect them from rotting. How good the design is doesn't matter near as much as whether the design is getting better or worse. If it is getting better, day by day, I can live with it forever. If it is getting worse, I will die. The problem with Wikipedia is that it only works in practice. In theory, it's a total disaster. The inherent complexity of a software system is related to the problem it is trying to solve. The actual complexity is related to the size and structure of the software system as actually built. The difference is a measure of the inability to match the solution to the problem. Remember that there is no code faster than no code. I have yet to see any problem, however complicated, which, when you looked at it in the right way, did not become still more complicated. Premature optimization is the root of all evil in programming. The key to performance is elegance, not battalions of special cases. The terrible temptation to tweak should be resisted unless the payoff is really noticeable. ... the cost of adding a feature isn't just the time it takes to code it. The cost also includes the addition of an obstacle to future expansion. ... The trick is to pick the features that don't fight each other. The cheapest, fastest, and most reliable components of a computer system are those that aren't there. The structure of a system reflects the structure of the organization that built it. Simplicity does not precede complexity, but follows it. Furious activity is no substitute for understanding. Simplicity is prerequisite for reliability. If you cannot grok the overall structure of a program while taking a shower, you are not ready to code it. All software gets usability tested … eventually. Know thy user, for he is not thee. A good understanding is always better than a bad misunderstanding. [On why contracts and documentation are not only necessary, but also important] An expert is a man who has made all the mistakes that can be made in a very narrow field. Good judgement comes from experience, and experience comes from bad judgement. People have not changed fundamentally in thousands of years. Technology changes constantly. It's the one that must adapt to us. Perfection is the shortest and surest road to bankruptcy. Early in the project you can have firm cost and schedule targets or a firm feature set, but not both. The real art of interface design lies in solving the right problem. Part of your job as a technical employee is to educate the nontechnical people around you about the development process. Studying and questioning users does no good if you tell them the answers. The key to being an effective programmer is maximizing the portion of the program that you can safely ignore while working on any one section of code. We do not see things as they are; we see things as we are. I would not give a fig for the simplicity this side of complexity, but I would give my life for the simplicity on the other side of complexity. Those who cannot tell what they desire or expect, still sigh and struggle with indefinite thoughts and vast wishes. It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other way … The sooner you start to code, the longer the program will take. A lot of times, people don't know what they want until you show it to them. Design is not just what it looks like and feels like. Design is how it works. When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of science. A brute force solution that works is better than an elegant solution that doesn't work. Simplicity — the art of maximizing the amount of work not done — is essential. On a typical project … the customer can't reliably describe what is needed before the code is written. The problem isn't that the customers are a lower life form. Just as the more you work with the project, the better you understand it, and the more they work with it, the better they understand it. One symptom that you have bogged down in complexity overload is when you find yourself doggedly applying a method that is clearly irrelevant, at least to any outside observer. Treat a design as a wicked, sloppy, heuristic process. Don't settle for the first design that occurs to you. Collaborate. Strive for simplicity. Prototype when you need to. Iterate, iterate, and iterate again. It ain't abstract if you have to look at the underlying implementation to understand what's going on. An inheritance quickly gained at the beginning will not be blessed at the end. Make it idiot-proof and someone will make a better idiot. I have no special talents. I am only passionately curious. We have to stop optimizing for programmers and start optimizing for users. A good architect studies bricks once, but studies people every time he designs a new building. Beware of bugs in the above code; I have only proved it correct, not tried it. The system should treat all user input as sacred. We aren’t creating computers. We are creating bicycles for the mind. Stubborness is a virtue ... if you're right. Don't mistake hours for productivity. You must never confuse faith and facts. Retain unwavering faith that you can ande will prevail in the end, regardless of the difficulties, and at the same time have the discipline to confront the most brutal facts of your current reality, whatever they might be. What is your questions-to-statements ratio, and can you double it? The great leaders don’t know the answer, and they know they don’t know the answers. That’s why they have great questions. Why don’t you invest more time in being interested? Don't make me think. The only thing more expensive than hiring a professional, is hiring an amateur. For every problem, there is one solution which is simple, neat and wrong. Supposing is good, but finding out is better. Microsoft in a recent survey found that most consumers use only 10% of the features on offer in Microsoft Word. In other words, some 90% of this software is clutter that obscures the few features people actually want. People often test to decide what color drapes are best, only to learn that they forgot to put windows in the room. In software, the chain isn't as strong as its weakest link; it's as weak as all the weak links multiplied together It is far better to adapt the technology to the user than to force the user to adapt to the technology. 'Intuitive' interfaces are easier to build when designers have a deep understanding of the users. Customers always know what's wrong. They can't always tell you what they want, but they always can tell you what's wrong. Never use a warning when you mean undo. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. You may be around seven different people in your lifetime, and those people won't necessarily be related.