The Design of Everyday Things, by Donald A. Norman, is all about the little details in our everyday lives. Basic things like doors, or telephones, or stoves. The design details of these objects can either be done well, or poorly. but without conscious effort we don't notice them either way.
Ideally, the design details are done well. We don't notice them (and we don't need to). If done poorly, however, we still don't notice them; instead we fault ourselves:
"I'm so bad with mechanical things." "I don't get on with computers." We naturally tend to fall into the pit of
learned helplessness (or
taught helplessness).
It's easy to fail as a result of poor design. Even something as trivial as a door has significant level of complexity when you break it down: Do you push or pull the door to open it? If so, on which side? Or maybe it slides? If so, in which direction? There are four ways to manually open a swinging door; how do we know which mode (or modes) of operation apply? The answer lies in the subtle design queues that answer these questions for us.
The sign says 'PUSH', but the handle is made for pulling! (Source) This picture shows a door giving mixed messages: The sign explicitly tells you to push the door open, but the handle
implicitly tells you to
pull the door open; because, after all, handles are for pulling on!
A classic example I can remember is one of the entrances to the Mathematics building at Reading University: There are two sets of double-doors with identical features on both sides. A horizontal plate positioned at hip-height and spanning the width of the door, suitable for pushing but also raised enough from the surface of the door so that you can wrap your fingers around the back of it and pull the door. At least it was obvious that the double-doors were meant to open in the middle, but the direction in which each set opened was a mystery to me. I failed at those doors many a time, and many others did too. (Don't even get me started on the
light switches.)
Only yesterday I saw a man at a service station try to open a door similar to the one pictured by pulling on the handle. The sign clearly instructed to "Push"! Was he stupid? Should he have read the sign? What if he was not literate in English? What if he was distracted? Was it really his fault that he failed to open the door on the first attempt, or was it the fault of poor design?
"Somehow, when a device as simple as a door has to come with an instruction manual -- even a one-word manual -- then it is a failure, poorly designed."
"If a design depends upon labels, it may be faulty. Labels are important and often necessary, but the appropriate use of natural mappings can minimise the need for them. Wherever labels seems necessary, consider another design."
The Smeg P64 Gas Hob features a sleek polished
stainless steel finish, a power output of 8 kW,
and automatic electronic ignition. But can you say
with certainty which dial controls which burner?Another scenario Norman talks about in his book is the arrangement of knobs on a stove-top: Burners are in a rectangular arrangement, yet the control knobs for them are, more often than not, in a linear arrangement. Left and right pairs of knobs control left and right pairs of burners respectively, that much is intuitive, but which dial in the pair controls the front burner and which controls the rear is a mystery.
Labels and diagrams are sometimes helpful, but often mask poor design.- Consider the benefit of a rectangular arrangement of the hob controls which mimics the rectangular arrangement of the burners. Would there still be need for diagrams that indicate the mapping of controls to burners?
- Consider the benefit of having a rectangular push plate on one side of a door, and a pull handle on the other: Would there still be a need for signs indicating "Push" and "Pull"?
Good design is intuitive and easy to use right out of the box -- without having to read the manual. After all, few people actually read the manual anyway. If your instructions aren't already blindingly obvious then, even if the manual
is read, its content will soon be forgotten by all but the most dedicated users. Perhaps the most amusing demonstration that "nobody reads the manual" is the book itself: First published in 1988, this book is "the manual" for designers, yet it seems a lot of its lessons have gone unlearnt over the past two decades.
"Good design takes care, planning, thought. It takes conscious attention to the needs of the user."Computer Software
The cunning thing is that all of these design principles also apply in the world of computer software:
The Pit of Success: in stark contrast to a summit, a peak, or a journey across a desert to find victory though many trials and surprises, we want our customers to simply fall into winning practices by using our platform and frameworks. To the extent that we make it easy to get into trouble, we fail. -- Rico Mariani
The Pit Of Success for doors: A door without a handle can only be pushed.
Another good example of how well this content relates to computer software is the principle:
Design For Errors.
There are many different reasons why users may make errors. Norman names seven distinct classes of error, and prescribes that designers should:
- Understand the causes of error and design in order and minimize those causes.
- Make it possible to reverse actions – to "undo" them – or make it harder to do what cannot be reversed.
- Make it easier to discover the errors that do occur, and make them easier to correct.
- Change the attitude toward errors. Think of an object’s user as attempting to do a task, getting there by imperfect approximations. Don’t think of the user as making errors; think of the actions as approximations of what is desired.
The Windows Recycle Bin was a way to allow recovery from the previously permanent action of deleting a file. Even the "Are you sure?" prompt was not enough, for that tends to confirm the action (deletion) when what you really want to confirm is the
file that is being deleted. Users tend to hit "Yes" with a sigh: "Of course I'm sure; I wouldn't have pressed delete otherwise!" only to realise a second later that they accidentally selected the wrong file.
Good designs will let the user take steps towards their goal and give them suitable feedback to allow them to reach it, but without imposing serious penalties or restrictions on the path they take to get there.
"The principle of good design can make complexity manageable."(The content from this book is nicely summarised
here.)
