Typical Appearance

Appearance generally differs. For operating systems like macOS and Windows, rotating the display screen is done through a drop down menu. For software like Preview and word processors, it also varies. Some objects are rotated through a button or an icon. Nevertheless, both styles are indicative enough to exemplify rotation.

Typical Behavior

Rotating is widely known and applied to objects in order to change their orientation or move in a circle-like motion around their center of mass. The flexibility of rotation surely enough differs from object to object. Depending on the software, some objects can rotate by fixed amounts, such as intervals of 90 degrees, and some can precisely rotate from 0 to 360 degrees.

Variants

Rotation is used on multiple applications across many different operating systems. Sometimes, it is not very obvious that an element can be manipulated by rotation. Depending on the category of device, the intended rotation method varies. For example, laptop computers often use the trackpad to rotate elements, while mobile phones use an accelerometer, allowing for the entire device to be rotated to manipulate an element.

• Photos can often be rotated and manipulated by using the correct rotation method depending on the device. On iOS, photos can be rotated by rotating the entire device, or simple pinching the screen with two fingers to move the photo using Multitouch. On macOS, photos can be rotated either through buttons or through the menu bar as done through 'Preview'.
• Single Applications often change their entire UI when the device is rotated. For example, the Calculator application on iOS changes from a simple calculator to a full scientific calculator when rotated into landscape mode. In contrast to iOS, macOS's UI and its applications does not change when the display is rotated. Only the orientation is changed. Because macOS devices have a much larger screen than iOS devices, there's no need to change the UI.

Priority Metrics

Rotation is an element that is being used more frequently in operating systems every year. Though rotation is somewhat intuitive and easy to learn, learnability is the top priority metric because it is important to know when rotating can be applied. The gesture of rotating itself is easy to learn, but it is somewhat difficult to learn which elements or user interfaces can be rotated. In addition, since this is a somewhat new user interface element, many new users are unaware of this feature in various applications. This makes learnability very important because new users are encouraged to quickly learn how to use the feature and memorize elements/applications that support rotation.

The second most important metric would have to be memorability. Most UIs have identical structures when accessing the functionality of rotating, like through buttons and drop down menus. The reason being for structured continuity across operating systems is that it helps the user become familiarized with the OS being used, and hopefully, be a satisfying experience for them. Introducing a new way of rotation just adds more difficulty for the user getting accustomed to the OS.

It is generally hard to make an error when rotating. The only error that can happen is if a user attempts to interact with an element/interface that cannot be interacted with. Therefore, elements that are known to be rotatable, must support rotation, which makes errors another important metric. Since rotation is a somewhat obscure and newer feature in many user interfaces, speed of performance (efficiency) is generally quite important as to whether or not the user continues to use the feature.

Key Characteristics

Because the functionality of rotating is dependent on other components like buttons on desktop platforms, its key characteristics intersect with those other components.

This is often different on mobile platforms however, as phones and tablets tend to have accelerometers. Because of this, many rotation features depend on the accelerometer rather than a different user interface component like a button.

Feedback and Communication

An important interaction design principle that encloses rotating, is the concept of feedback and communication. Whenever a rotation occurs:

1. through buttons, a continuous conversation between the user and the UI must be present. For macOS, an image in 'Preview' is not rotated at lightning speed. When the button is clicked, an animation occurs to clearly indicate to the user that the image is being rotated and exactly how.
2. through clicking and dragging, the object being rotated must rotate in the direction the user points to on the trackpad. Doing so, lets the user know that they are in control of the computer.
3. on mobile operating systems, through the accelerometer detecting the new orientation of the device and responding properly to which direction the user rotated the device.

Consistency

The buttons used and techniques used for rotating objects, need to be familiar to the user. This way, the user can easily work their way around the functionality of rotating because of being familiar with it beforehand. The rotation of components on different operating systems and applications do not have to look the same. Rather, they mustn't force their users to learn new ways of rotations; memorability is an important aspect of rotations.

User Interface Changes

Many times applications will not explicitly specify if the application supports landscape mode. Occasionally, as is the case with many iOS games, applications will only support a landscape mode and not portrait. The biggest indication as to whether an application supports both orientations is a change in User Interface.

An example of this change in UI is the Messages application in iOS 10. Messages changes from the standard conversation view in portrait mode to a handwritten message view in landscape mode.

In landscape mode, the landscape keyboard can also be accessed by pressing the Keyboard button on the bottom-right toolbar.