User Inteface (UI)

Character User Interface (CUI) is a kind of user interface that uses only alphanumeric characters and pseudographics for input-output and presentation of information. It is characterized by a low demand for I/O hardware resources (in particular, memory) and high information display speed. CUI appeared at one of the initial stages of computer technology development. The disadvantage of this type of interface is the limited visual media, due to the restricted number of characters included in the font provided by the equipment. Programs with a text interface can implement a window interface, which is particularly facilitated by the use of pseudo-graphic symbols. CUI Features In the simplest mode, the character interface uses only the command-line, but many programs use interactive elements to create a more user-friendly visualisation. The character interface implements all the basic elements - menus, buttons, switches, checkboxes, drop-down lists, scroll bars and so on. Many programs implemented a well-developed window system, which was facilitated by libraries like CScape, D-Flat, Turbo Vision and many others. Some had interchangeable themes (for example, DOS Navigator) and supported various interactive devices such as a mouse, joystick, light pen. At the software level, console programs use standard input-output devices (stdin, stdout, stderr) to enter and display information, although they can open other files, network connections and perform other actions available in the operating environment. Displaying printed characters in stdout and stderr results in the appearance of these characters on the output device and their receipt by the user. Console programs for some operating systems, especially UNIX, are usually able to work on an advanced user interface functionality. To simplify the writing of such programs, the ncurses library is widely used.

Graphical User Interface (GUI) is a kind of user interface in which elements (menus, buttons, icons, lists, etc.) presented to the user on the display, are executed in the form of graphic images. In the GUI, the user has random access (through input devices such as a keyboard, mouse, joystick, etc.) to all visible display objects (interface elements) and directly manipulates them. Most often, GUI interface elements are implemented on the basis of metaphors, and display their purpose and properties, which facilitates the understanding and mastering of programs by untrained users. The graphical user interface is part of the user interface (UI) and defines interaction with the user at the level of visualized information. Classification Simple: typical screen forms and standard interface elements provided by the subsystem of the GUI; True-graphic, two-dimensional: non-standard interface elements and original metaphors realized by the app's own tools or by a third-party library; Three-dimensional. DWIM One of the requirements for a good graphical interface of the software application is the concept of "Do What I Mean". DWIM requires that the system works in a predictable way so that the user intuitively knows in advance what action the program will perform after receiving the command. Advantages The graphical interface is user-friendly, especially for people who’ve used other apps. Usually, the users can easily find in the interfaces similarities with other programs, working on the same operational platform, like the hamburger icon for mobile app menus on smartphones or the printer sign for printing documents. Disadvantages Greater memory consumption compared with the text interface; It is more difficult to organize remote work; Automation must be integrated in the structure of the DWIM at the pre-development stage. In other cases, quite often it’s easy to develop a new app instead of adding such features to the existing system, as automation is impossible for the current structure. The graphical interface is not always "friendly" for users who have begun to familiarize themselves with the computer from the command line interface. Examples of systems using the GUI: Mac OS, Android, iOS, Microsoft Windows, GNU / Linux, GEM, Solaris,  Atari TOS, BeOS, MeeGo.

Usability in the design creation - convenience and ease of use - the ability of the digital product to be intuitively understood, studied and used. This includes attractiveness to the user under specified conditions (ISO / IEC 25010); the attribute of a system, product or service, in which a particular user can operate the system under certain conditions to achieve specified goals with the required efficiency and satisfaction (ISO 9241-210). Usability in mobile and web software development is a result of the software design stage, which provides users with convenient facilities for app interaction, software or websites. Good usability requires that: A website has a decent layout, is easy to navigate, consistent across all web pages, and useful and informative to visitors; An app should be bitsize and clear; content should be readable on different screen sizes, all the buttons and links are easy to use without rub contact. The intuitive design accompanies the features, while the main functions are obvious and easily available to users. There are two main ways to assess the usability of the product: Direct evaluation based on the analysis of the efficiency and satisfaction achieved, as a result of product operation in real conditions: if in the above conditions one system is more ergonomic than the other, then the evaluation should detect this; Indirect evaluation based on the analysis of individual sub characteristics that reflect certain properties of the system in the specified operating conditions. Direct evaluation is considered in the ISO 9241-11 standard, which assumes that the ergonomics of the system depends on all indicators affecting the operation of the system in real conditions, including both organizational indicators (for example, labor skills, location or appearance of products), and individual differences between users, for example, in the cultural level and preferences. Indirect evaluation is considered in ISO / IEC 25010, which describes the following usability characteristics: Appropriateness recognizability: an ability of the user to understand whether the product or system is suitable for his or her needs, based on initial impressions, documentation and other information provided; Learnability: a degree of effectiveness, productivity and user satisfaction by learning how to use the system; Operability (controllability): ensuring the ease of management and control; User error protection: a degree to which the system protects the user against errors; User interface aesthetics: a degree to which the user interface satisfies the user and gives him pleasure from the interaction process; Accessibility: an ability to use a product or system by a wide range of people with a wide variety of opportunities ((including limited). The best way to estimate the usability of the existing or new software is to implement the usability testing, inviting the real users to do the set of standard procedures as a test.

Net Promoter Score (NPS) is an index that identifies customer loyalty to a product or company and is used to assess readiness for re-purchases. How It Works Measuring the NPS loyalty index involves several steps: Consumers are asked to answer the question “What is the probability that you would recommend a company/product/brand to your friends/acquaintances/colleagues?” On a 10-point scale, where 0 corresponds to the answer “I will not recommend it in any way”, and 10 - “ I will surely recommend. " Based on the estimates obtained, all consumers are divided into 3 groups: 9-10 points - product/brand promoters, 7-8 points - passives, 0-6 points - detractors. Calculation of the NPS index itself. NPS =% supporters -% critics As a result, the the user’s loyalty score calculated on the scale from -100 to 100. If all the customers are willing to recommend the product, the score will be about 90-100, if they are not willing to recommend it - the NPS will drop to -90-100 points.   NPS trade mark was registered for the marketing tool, which automates the calculation of the above mentioned data. History Frederick Reichheld is considered the founder of the method, who first announced the method in the article “One Number You Need to Grow”, published in the Harvard Business Review in December 2003. In 2006, he released a book entitled “The Ultimate Question: Driving Good Profits and True Growth”. He continued his arguments on the loyalty, profitability and growth of the company. In 2001, Reichheld conducted research in more than 400 American companies, where the main task was to measure the influence of customer loyalty (measured by NPS) on its growth rate. The main result was the conclusion that the average NPS by market in the industry was 16%, but for companies such as eBay and Amazon NPS it was 75%. Reichheld does not say that communication is present everywhere: it is absent altogether in monopolistic markets. However, industries such as passenger air travel, insurance and car rental have become a prime example of interconnection. This is obvious, since these companies are service providers, where customer satisfaction and loyalty depend on the level of customer service. As a result, many companies have become adherents of this technology, including Apple, American Express,  eBay, Amazon, Allianz, P & G, Intuit,, Philips, etc. For certain industries, especially software, it has been proven that Detractors often stay with the company while Passives leave.  This seems to be a relatively high barrier to trade. Faced with criticism of the promoter's score, proponents of the network promoter's approach stated that the proposed statistical analysis only proved that the "recommendation" problem was similar to other indicators in predictive capacity, but failed to solve the real problem and this is the core of the argument presented by Reichheld. Proponents of the method also argue that third-party data analysis is not as good as analyzing the company in its own set of customers, and the actual benefits of the method (simple communication concepts, short survey, customer follow-up features ) exceed any statistical disadvantage of the approach. They also allow inquiries using any other issues to be used in the net promotion system, as long as it meets the criteria to securely classify customers as promoters, passives and detractors.

is the fifth generation mobile communication technology based on the IMT-2020 standard. The speed of Internet access in the 5G network is predicted at around 10 Gbit/s. 5G reduces the signal delay to one millisecond - against 10 milliseconds on 4G networks and 100 milliseconds in 3G. New generations of mobile communication appear every 10 years. Within this interim, time is spent on the development of technology, standards and infrastructure upgrades. It is expected that the 5G network capacity will be enough to serve more than 1 million devices per 1 km² at an average speed of 100 Mbps. Read more about 5G opportunities for business. Who Deals with 5G Networks in the World Today 5G technologies are used by: research laboratories (for example, the 5G Lab Germany laboratory at the Dresden Technical University); mobile operators (British Vodafone, American Verizon and AT&T, Japanese NTT DoCoMo, Swedish Teliaetc); telecom equipment suppliers Swedish Ericsson, (Chinese Huawei, Finnish Nokia, South Korean Samsung, etc.). 5G Applications These apps and services require significantly higher characteristics of a mobile Internet connection, which cannot be implemented in existing commercial LTE networks. It is expected that 5G networks will allow connecting many devices capable of establishing billions of connections, due to which it will be possible to create new services in: Tactile Internet (transmission of touch), IT and Telecom, automotive industry - self-driving cars, entertainment industry, education, agriculture and many others. Due to the 5G networks, it will also be possible to improve the quality of use of already existing services, where large volumes of traffic are involved. Launch of the World's First 5G Network October 1, 2018 Verizon announced the launch of the world's first commercial network of the fifth generation (5G). The operator has deployed it in four US cities: Sacramento, Houston, Los Angeles, and Indianapolis. The company officially declared Houston resident Clayton Harris "the first customer of the 5G network in the world,” which provides an average speed of 300 Mbit/s, and the maximum of 940 Mbit/s.

is a server platform for working with JavaScript through the V8 engine. JavaScript performs the action on the client side, and Node let the commands, written on JS to be implemented on the server. With Node, front-end programmers can write full-fledged software applications. Node can call commands from JavaScript code, work with external libraries, and act as a web server. Node Advantages Node is easier to scale. When thousands of users connect to the server at the same time, Node works asynchronously, that is, it sets priorities and allocates resources more intelligently. Java, for example, allocates a separate stream for each connection. Features Asynchronous scripts based on events. All Node.js APIs are asynchronous: non-blocking downloads. In essence, this means that a Node based server never expects data to be returned from the API. After the call, the server proceeds to the next API, and the Node.js events notification mechanism helps the server to get a response from the previous call. Very fast. Being built on the Google Chrome V8 JavaScript browser, the Node.js library runs very quickly in code. Single-threaded but easily scalable - Node.js uses a single-threaded model with an event loop. The Event engine helps the server respond in a non blocking way and provides high scalability, unlike traditional servers that create limited threads for processing requests. Node uses a single-threaded program, and the same program can serve much more requests than traditional servers, such as the Apache HTTP Server. No buffering - Node.js apps do not buffer data. Apps simply output data in parts. Where is Node.js used? Node.js has established itself as an ideal technological solution in the following areas: Input / Output applications Streaming apps Intensive use of data in real time (DIRT) JSON API based applications Node is successfully used by such large companies as eBay,Microsoft, PayPal, General Electric, Uber,  GoDaddy, Wikipins, Yahoo!. Read how we build great apps with Node.js.