Usabilityユーザビリティ is the degree to which users can reach their goals with a system effectively, efficiently and with satisfaction, in other words how easy it is to use.
Aspect
Meaning
Example
Effectiveness
The goal is achieved correctly and completely
Confirming a booking for the desired date and time without mistakes
Efficiency
Little effort or time is needed to get there
Finishing an order with only a few screen changes
Satisfaction
It feels pleasant to use, without frustration
Wanting to use it again after finishing
It is judged from the user's experience, such as whether people can reach the operation they want without getting lost and whether mistakes are unlikely. Reducing the effort of data entry is also a way to raise usability.
AnalogyIt is like changing trains at a station you have never visited, relying only on the signs. If the signs are clear and the walk is short, that station is easy to use.
How to rememberIt is usable plus the noun-forming suffix -ity, so read it as "the degree to which something is usable."
Exam points
ExamWhen the same value tends to be entered again and again, presetting the previously entered value as the default saves reselecting it and speeds up input.
ExamAutocompleteオートコンプリート suggests candidates that match the partly typed text based on strings entered before, a feature that cuts typing effort and improves usabilityユーザビリティ.
Mix-upUsability is how easy something is for its intended users, while accessibilityアクセシビリティ is whether everyone, including older people and people with disabilities, can use it.
Human-centered design人間中心設計 is a way of designing that starts from real users and their context of use, evaluates design proposals from the user's standpoint, and repeats improvement until the requirements are met.
Understand the context of use
Specify the requirements
Produce design solutions
Evaluate from the user's standpoint
Evaluate them, for example by having users try them, and go back to an earlier activity to improve if the requirements are not met.
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The specification is not fixed on the developers' assumptions alone; evaluation results feed into the next round of design. For example, the team cycles through understanding the context of use, specifying requirements, producing designs and evaluating them, and returns to an earlier activity when an evaluation falls short.
AnalogyIt resembles a tailor who measures the customer, has them try on a basted fitting, alters it, and keeps adjusting until it fits perfectly.
How to rememberIt is abbreviated HCD. The person standing at the center of the design loop is the user, not the maker.
Exam points
Mix-upUsabilityユーザビリティ is the quality of being easy to use itself, while human-centered design人間中心設計 is the way of working that raises that quality by repeating evaluation from the user's standpoint and improvement.
Gesture interfaceジェスチャーインタフェース is an umbrella term for input methods that read body movements, such as those of the fingers or hands, and use them to operate a device.
Gesture interface
Movements that touch the screen
Touching with one finger
Touching with several fingers at once
Movements without touching the screen
Hand motions read by a camera or sensor
Besides tracing a finger across a screen, movements that never touch the screen, such as hand motions read by a camera or sensor, can also serve as input. Its strength is that people can operate devices much as they move in everyday life, without learning how to handle a keyboard or mouse.
AnalogyIt takes the body language you use without words, beckoning to say "come here" or holding up a palm to say "stop," and turns it into commands for a device.
How to rememberGesture means a movement of the body or hands. Placed before interface, it names a point of contact where you deal with a device through movement.
Multi-touch interfaceマルチタッチインタフェース is an input method that detects contact at several points on the screen at the same time and lets you operate by combining them.
Gesture
Finger movement
Main result
Pinch out
Spread two fingers apart
Zooms in
Pinch in
Bring two fingers together
Zooms out
Rotate
Move two fingers as if drawing a circle
Changes the orientation of an image or other item
A pinch outピンチアウト, which spreads two fingers to zoom in, and a pinch inピンチイン, which brings them together to zoom out, work only because several contact points can be handled at once. A method that detects just one contact point cannot perform such gestures.
AnalogyLike a pianist pressing keys with fingers of both hands at once to play a chord, it combines the movements of several fingers to convey one meaning.
How to rememberMulti means many or several. It is the same prefix as in multimedia, and here it means there are several touch points.
Exam points
ExamA method that operates a device by touching two or more points on the screen at once and combining those finger movements is multi-touchマルチタッチ.
Mix-upMulti-touch interfaceマルチタッチインタフェース uses simultaneous contact at several points on the screen, while gesture interfaceジェスチャーインタフェース is the umbrella term for input by body movement, including hand motions that never touch the screen.
Tapタップ is the most basic touch gesture: lightly touching one point on a touch screen with a finger and lifting it right away.
It corresponds to a mouse click and is used to select or run icons and buttons. There are also variations that change how you touch, such as a double tapダブルタップ, two quick light touches on the same spot.
AnalogyIt is close to pressing an elevator's floor button lightly with a fingertip. A touch and a release are enough to select and confirm.
How to rememberThe English word tap means to strike lightly. Picture tapping someone on the shoulder to get their attention.
Exam points
Mix-upTouching and lifting at once is a tapタップ, while keeping the finger in place for a while is a long press長押し. What separates them is how long the finger stays.
Swipeスワイプ is the gesture of sliding a finger in one direction without lifting it after touching the screen.
It is used to move what is on screen, such as switching screens, scrolling through a list or advancing to the next photo. The direction of the slide decides the result, such as going back or moving forward.
AnalogyIt is like sliding a sheet of paper across a desk with your fingertip pressed on it to move it aside.
How to rememberThe English word swipe means to rub or sweep quickly. Passing a card quickly through a reader is called by the same word.
Exam points
Mix-upTapタップ lifts the finger without moving it from where it touched, while swipeスワイプ keeps contact and slides the finger. The difference is whether the finger moves.
VUI (Voice User Interface) is a way of operating through an exchange in which the user speaks with their voice and the device answers with sound.
The user speaks
Speech recognition reads the words
The requested task is carried out
Speech synthesis replies
It reads the result aloud with speech synthesis and answers the user by voice.
4 / 4
The device converts spoken words into text or commands with speech recognition音声認識 and reads its replies aloud with speech synthesis音声合成. Because it works without looking at or touching a screen, it helps when your hands are busy or the screen is hard to see.
AnalogyIt is like asking a family member out loud to "set the timer for 3 minutes" while your hands are busy cooking, and hearing "done" in reply.
How to rememberThe V stands for Voice. Swap the G (Graphical) in GUI, where you work with on-screen parts, for a V, and you get a point of contact that uses voice instead of a screen.
Exam points
Mix-upVUI uses the voice and a gesture interfaceジェスチャーインタフェース uses body movements such as those of the fingers or hands as input. They differ in what serves as the means of input.
Key points
Usability is ease of use measured by effectiveness, efficiency and satisfaction, and designs that cut input effort raise it.
In human-centered design, when an evaluation does not meet the requirements, the team returns to an earlier activity and repeats improvement.
A multi-touch interface allows gestures that use several contact points at once, such as spreading or pinching two fingers.
VUI carries a spoken exchange through speech recognition and speech synthesis, so it can be operated without hands or eyes.