Identify Various Types Of Pointing Devices

In a graphical user interface, the pointer is a small symbol on the screen. A pointing device is an input device that allows you to control the pointer. Common pointing devices include the mouse, trackball, touchpad, pointing stick, joystick, touch screen, light pen, and a stylus. A mouse is a pointing device, designed to fit comfortably under the palm of your hand, that is moved across a flat surface. A trackball is a stationary pointing device with a ball mechanism on its top. A touchpad is a flat, rectangular pointing device that is sensitive to pressure and motion. A pointing-stick is a pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on the keyboard. A joystick is a vertical lever mounted on a base. A light pen is a handheld device that contains a light source or can detect light. A touch screen is a touch-sensitive display on the screen. A stylus looks like a ballpoint pen but uses pressure, instead of ink, to write text and draw lines. An electronic pen can be used on a graphics tablet, which consists of a flat, rectangular, electronic plastic board used to input graphical data.

Explain How A Mouse Works

As you move a mouse across a flat surface, the movement is translated into signals that are sent to the computer, and the pointer on the screen also moves. When you move the mouse to the right, the pointer moves to the right on the screen. For Windows users, the top of a mouse has at least two buttons and sometimes also a wheel. Generally, you use a mouse to move the pointer on the screen to an object and then press a button, or click, to perform a certain action on that object. Other operations you can perform using a mouse include right-click, double-click, drag, right-drag, rotate wheel, and press wheel button.

The major advantage of a mouse is that it is easy to use. The disadvantages are twofold: first, the mouse requires additional desk space, making it difficult to use in cramped locations; and second, mouse use demands that a hand be taken from the keyboard.

Describe Different Mouse Types

The original mouse was a one-button, cigarette-pack shaped device invented by Doug Engelbart in 1964. Since its introduction in 1965, the mouse has gone through several transformations. Microsoft’s “green eye” mouse, an early mouse with two buttons, was released in 1983 and now is a collector’s item. Other interesting mouse variations include Spectrum’s RingMouse (which uses infrared to point), Interlink’s wireless mouse (often used for presentations), and Interlink’s DuraPoint PC mouse (an incredibly durable mouse that gained the Pentagon’s interest).

A mechanical mouse has a rubber or metal ball on its underside. When the ball rolls in a certain direction, electronic circuits in the mouse translate the movement into signals that are sent to the computer. For better traction, you should place a mechanical mouse on a mouse pad. An optical mouse has no moving parts; instead it uses devices that emit and sense light to detect the mouse’s movement. An optical mouse can be used on nearly all surfaces, is more precise than a mechanical mouse, and does not require cleaning. A cordless mouse, or wireless mouse, is a battery powered device that transmits data using wireless technology, such as radio waves or infrared light waves. A cordless mouse uses technology very similar to that of a cordless keyboard.

Explain How Voice Recognition Works

Voice input is the process of entering data by speaking into a microphone that is attached to the sound card on a computer. Voice recognition is the computer’s capability of distinguishing spoken words. The first voice recognition programs were speaker dependent. With speaker-dependent software, the computer makes a profile of your voice, which means you have to train the computer to recognize your voice. Today, most voice recognition programs use speaker-independent software, which has a built-in set of word patterns and does not have to be trained to recognize your voice. Some voice recognition software requires discrete speech. It means that you have to speak slowly and separate each word with a short pause. Most voice recognition products, however, support continuous speech. It allows you to speak in a flowing conversational tone.

Some experts believe voice input eventually will be the most common way to operate a computer. Speech recognition is particularly welcome to people with certain disabilities. Although speech recognition continues to improve, developers admit that advertisements touting high accuracy rates generally assume a standard vocabulary. Specialized words, regional accents, and local dialects reduce accuracy. Even a 95 percent accuracy rate, meaning that on average 1 out of every 20 words is wrong, may not inspire confidence. (Imagine if, in conversation, every 20^th word spoken was misinterpreted.) Nevertheless, voice recognition systems are gaining in popularity.

Understand How To Input Data Into A Handheld Computer

To satisfy the input needs of many different types of users, handheld computers provide many different ways to input data. A handheld computer typically includes a basic stylus. With the stylus, you can enter data using an on-screen keyboard or using handwriting recognition software that translates handwritten letters and characters into symbols the computer understands. Other input alternatives available with some handheld computers include attaching a full-sized keyboard, transferring data from a desktop computer, using voice input, and attaching a digital camera.