As designers cannot control the network speed or processing speed of the device; additional screens may be used to keep the user busy while the app fetches the desired information. Users should intuitively be able to navigate through your app via clear pathways and be able to complete all primary tasks without requiring any explanations. Smartphone adoption and its influence on people’s lives is growing at an exponential rate. From the perspective of a designer, an exceptional UI for mobile app can only be ensured when you follow some tried and tested UI design principles. When you are out to develop an app that has the right blend of aesthetics and functionalities, expert designers are indispensable. ALL LEFTS, 5 Ways Saudi Businesses Can Design the Best Customer Experience, 10 Must-Read Articles for Getting Started with UX, Design, Professional Development, Usability, User Experience. It’s important to have sufficient contrast between content and background in your designs so it’s legible, in any setting, even outside in the sunlight. Apps can suggest actions or provide warnings, but they shouldn’t be the ones doing the decision-making. Principles of User Interface Design The placement of knobs, buttons, and switches is as essential to the making of a good product as the firmware. Best Mobile App Design The best mobile app designs keep the user and their needs as the forefront focus. Delivering extraordinary experiences for users to experience is the way forward. Hence, if you want to develop a great, classy mobile app interface, following the design principles are definitely important. When designing mobile apps, you can't ignore interaction design. A software application must be as easy to navigate and use as possible… smaller than 16 pixels (or 11 points) becomes challenging, WC3’s Web Content Accessibility Guidelines, Interested in UX Design? With offices in Riyadh and Dubai, our team of UX Researchers, Designers, and Developers deliver custom designed and built software to help businesses succeed. The success of a mobile app boils down to its performance and usability. There are millions of mobile apps across several mobile platforms but very few are able to make the cut, and the user experience has a lot to do with it. People use their thumbs more often than any other finger while using their smartphones. Keeping in mind right- and left-handedness is also a design feature to consider. There are several such features that can be instrumental in augmenting the beauty of the app. This gives the user a sense of freedom and transparency. Communicating your designs in a clear, simple layout delivers your message effortlessly. By Niall Murphy. Hence, tiring the reader. If an app requires signup, let them demo it first or continue as a guest to sample it before making the decision to commit. Jakob Nielsen’s heuristic principles have stood the test of time, but can sometimes be difficult to implement during the design process. Following this approach emphasizes one to think in terms of context, problem, and the user. Additionally, it’s extremely difficult to use the expertise and existing documents to explain what an excellent and direct-viewing operation interface is. Users should intuitively be able to navigate through your app via clear pathways and be able to complete all primary tasks without requiring any explanations. To increase the chances of success when creating user interfaces, most designers follow interface design principles. This theory also holds true for the mobile apps, irrespective of the platform. But what you can do is work around the problem by minimizing the need to enter data in your designs. Legible content. See more ideas about application design, app design, mobile app design. Beyond communication and information gathering, services and features such as banking, placing orders, healthcare tracking, and even home security have become part of the smartphone experience. Delivering a great mobile UX takes into consideration all different types of users. Clutter is terrible on a desktop, but it’s way worse on mobile devices where users have limited screen space. Content should be accommodated for smaller screens while maintaining all the necessary information. Human attention spans are really short. This makes it extremely important to grab your users’ attention within the first few seconds of interaction with your products. The user experience must be layered. Identify the primary users. . By filling out your details below, you’ll receive the full course syllabus which includes the course outline and what you’ll learn from the course. more than 28 percent of the world’s population used a smartphone. All the targets in mobile interfaces design should be big enough so users could tap them easily with a finger. Such situation might cause hindrance in acceptance of the app and hence, can impact the success. All these changes can make a big difference in task success rate and task time, and more importantly keeping the user engaged and satisfied with your product. Happens to the best of us. Mobile contexts. At UXBERT Labs we specialize in UX Research, Design & Development services that deliver world-class experiences. Satisfaction: How pleasant the experience of using the design was. When it’s done well, users don’t even notice it. It is imperative to create user-centered designs to improve interactions and enhance user satisfaction. Jakob Nielsen, a renowned web usability consultant and partner in the Nielsen Norman Group, and Rolf Molich, another prominent usability expert, established a list of ten user interface design guidelinesin the 1990s. Crowding a small space with too much content makes it difficult and straining for users to read. Designers only have a few seconds to catch people’s attention before they abandon an app or site in favor of one that’s more user-friendly, intuitive, or … The most important part in choosing your text and background is to test it out with users. Make use of the mobile phone’s features, like the camera to scan barcodes, GPS for identifying locations and touch ID in place of passcodes to simplify journeys. is a key priority for creating seamless experiences. User interface principles to follow in mobile app design service The design layout must be consistent: The importance of consistency cannot be over-emphasised. GUI design has become the best choice of user interface design. Driverless Tech Can Change the Future of India’s Logistics – But Are We Ready for it? Every brand has a story and that must be showcased through the app design. Following these established mobile UX design principles will create a better overall user experience for people visiting a mobile site or using a mobile app. This statistic is useful to keep in mind when designing to accommodate for the thumb’s reach zone. In this article, we will cover seven mobile app design principles that will help you design an interface for a mobile app with more chances to succeed. It is quite evident that the user interface design of a mobile app holds much importance as it is directly responsible for the performance of the app and thus, also impacts its success. If you wanted to design a great and fully-functional mobile application interface, you should consider design principles that are hugely important. Research findings on how people hold and interact with their mobile phones found that 49% of people rely on one thumb. 13 Books to Get Started Today. Seamless experiences are invisible. Ever start typing on your mobile phone and find a few extra letters that have nothing to do with waht hyour’re ar3e tryaing to saay? Mar 30, 2020 - Explore Aigdy Aukkaraya's board "application design", followed by 318 people on Pinterest. Meet the user's needs. Only the most important, relevant and necessary functionalities should be added to the screens so that the users are served with the options that they require. That’s why including an undo button in your designs will relieve many people (including yourself) when mistakes are made. When it comes to talking about the design principles cheap canada goose , they are loose guidelines that professional designers can stick to enhance the quality of a user interface design. When you are designing an app, you cannot use the same design layout for all the mobile operating systems for instance, Android, iOS, and Windows. Memorability: The ability of users to remember how to use the system. Prioritize content and remember that notifications for new content should appear without interrupting primary content! The ultimate aim to launch the mobile app is to reach out to the mobile users and expand the horizon of the brand. Don’t make users have to switch between pages and apps to get something done. In the Windows Phone UI Design and Interaction Guide, Microsoft suggests a touch target size of 9mm/34px with a minimum touch target size of 7mm/26px. Apple’s iPhone Human Interface Guidelines suggest a minimum target size of 44 pixels wide x 44 pixels tall. Relieve users by providing autocomplete, recent search history and location detection to reduce data entry requirements and accelerate the experience. User attention is a precious resource, and should be allocated accordingly. and remember that notifications for new content should appear without interrupting primary content! With an over populated app market to cope with, you have few seconds to impress the users with your app. Help them reduce typing required by shortening forms, removing unnecessary fields and using ‘remember me’ options for future use. Crowding a small space with too much content makes it difficult and straining for users to read. 8 seconds to be exact. The ultimate aim to launch the mobile app is to reach out to the mobile users and... 2. Content is the first element which makes a mobile app to be designed for humans. Functional, flexible, and responsive mobile designs are what users today expect to encounter. Internet Appliance Design. In 2016, more than 28 percent of the world’s population used a smartphone. These user interface elements are those that can be very crucial for an app and are mostly impacted by the user interface of the app. The most basic principle of interaction design is to meet the user… The flow from one screen to another should be optimized to ensure that there is no waiting time as it annoys the users and make them look for the alternatives. The key to mobile typography is readability. Information required to use the design (e.g. Simplify the process and have all the information needed readily available. The user interface (UI) is a critical part of any software product. Usability testing is essential for the success of your products. A mobile app is built with a target audience in mind which might expand at a later stage. 1. The 10 principles of mobile interface design 01. Content Prioritization. Communicate with your users to understand what they need, and deliver it. The important part is to make interface elements big enough to capture these actions. But getting the right amount of contrast isn’t always easy. Learnability of your design is key for its success. Typing on small devices can be annoying and unfortunately there really isn’t a direct solution to it, other than autocorrect (which let’s be honest, isn’t always accurate). Adding space between text aids the user in reading and creates a feeling that there isn’t so much information to take in. Interface elements need to be big enough to capture actions on touch screens. By ensuring that your mobile app is completely optimized to be as user-friendly as possible, you'll be able to offer your customers an experience that instills trust and helps build a relationship with the user. Throughout iOS, people—not apps—are in control. The key to any successful product is to continuously test and optimize. Regardless of which methodology you plan to use, with the content-first approach, you are bound to create a unified voice. When designing your products, keep interface elements to a minimum. Here are 10 tried and tested UX design principles that are key to creating great mobile user experiences. 10 UI Design Principles to Stick to while App Designing 1. Crafting any design requires certain considerations that would affect its performance and usability. Small touch targets can be frustrating because they require more accuracy and are prone to errors. They are called 'heuristics' because they are more in the nature of rules of thumb than specific usability guidelines." With a penchant for writing interesting and highly informative blogs, she has been contributing to various magazines and forums. When the performance of the app which include loading time, content display, navigation etc., is not considered while UI design, it is seriously impacted when code is written for the app. When the user needs to know what’s going on, let them know! Share & Learn knowledge of business, technology, and self-management for your professional career. User experience design encompasses traditional human–computer interaction (HCI) design and extends it by addressing all aspects of a product or service as perceived by users. © 2018 UXBERT. People interact with touch screens using their fingers, maybe even their toes, but that’s none of our business. Go beyond basic usability features to create pleasant and addictive experiences. Design principles act as guidelines that designers can take into consideration for improving the superiority of a user interface design. 10 Usability Heuristics for User Interface Design "The 10 most general principles for interaction design. Common features should be placed in easily accessible regions, while actions such as delete buttons should be placed in areas harder to reach to avoid errors. Follow these principles to create the UI designs that accelerates and enhances the app’s performance and cater to the users in the way they expect. In mobile app development, the UI (user interface) and UX (user experience) play the most significant roles in a mobile app’s success. In 2015, more than 25 percent of the world’s population used a smartphone. • What different your app has to do than your rivals? Hence, a balance must be maintained between the interface and the performance of the app. With each round of testing, you uncover new ways to improve your design to meet your users needs. Display only essential content and functionalities the user needs. How and To What Extent Virtual Reality Will Impact Marketing? App design team must be in consultation with the development and business team to come up with design layouts that serve the purpose in entirety without stuffing the screen with unnecessary clutter. Developers often fail to take the perspective of the end user into account. • What better your app can do than your rivals? How Businesses Should Prepare Themselves for Generation Z. field labels or menu items) should be visible or easily retrievable when needed. Your mobile app icon should look like a million downloads. To further reduce clutter, use icons instead of text wherever possible. Do not overload the user with more than they need to know or … Place the User at the Center; As always, the first UI design principle is to focus on people (or, the “user… 2. There is no point in creating something that already exists, and it is the same with mobile app design. Changing settings, controlling notifications and cancelling actions provides the user with a sense of control over the system. Accessibility behavioural features should be made available to users to make navigation easier. Apple offers several accessibility features like double tapping the home button which drags the entire screen to an easier reach zone. All Rights Reserved. Menu lists, either short or long, should have progressive disclosure and simple terminology so as not to confuse your users. It implies that while the app must excite the new users with its design and performance, it must also have different features that unfold while the users interact more with the app. Doing What You Love Is Going To Be Fucking Hard, How to Crush Your Goals in 2017, According to Harvard Research, How to Stop Feeling Like an Imposter at Work, How AI Impact Software Development in 2018, How Machine Learning is Transforming Healthcare, How to Create The Next Business Success Story, How Babies and Startups have Plenty in Common. The user interface design of an app has substantial effect on content presentation, features, navigation, hardware access, graphics and hence, performance. High performance can be achieved only when the design discussions also accommodate the topic of performance and incorporate these UI factors while designing. The apps can leverage these features that enhance the usability of the app. 6. Nevertheless, in spite of the unpredictable popularity of GUI, few application programs have good interface design and live up to graphic user interface design principles. “If the user can’t use it, it doesn’t work.”– Susan Dray. Human attention spans are really short. Even if you are launching your app across all the platforms, simply porting the code from one platform to another will not suffice. Unenumerable mobile applications launch on the daily bases, but not all the developers are experts and have that capability to make their applications great and stand out. Learnability of your design is key for its success. People use their phones everywhere. 6 Best UI Design Principles to Develop Mobile Apps 1. It keeps the interest of the users intact as they discover more functionality upon deeper involvement with the app. Display keyboard variations depending on the required data, for example for phone numbers provide the numeric keypad for faster input. Looking for a UX agency in Dubai or Saudi? If you are contemplating building an app for your business, you’ve come to the right place. Don’t forget about the clear visual feedback. The strategy for optimal mobile typography is a balance between legibility and space conservation. So that’s what you need to give them. Developer & App Marketing, AppsChopper. Mobile mindset. When navigating through your app, the user should always know where they are without wondering how they got there, or what they are to do next. Your email address will not be published. Generally, anything smaller than 16 pixels (or 11 points) becomes challenging to read for any screen. This article illustrates the delicate relationship between the two. Not only is the size of the target important, but so is the spacing between targets. It needs to be comprehended that design and development go hand in hand and you cannot isolate the two process. Many of these principles boil down to “make life easy for the user”. 2… Communicate with your users to understand what they need, and deliver it. Simple designs are what keep the user engaged and at ease with products. User experience design (UXD, UED, or XD) is the process of supporting user behavior through usability, usefulness, and desirability provided in the interaction with a product. Graphic metaphors refers to the common icons that are used in place of the text. Cluttering a user interface overloads your user with too much information — every added button, image, and line of text makes the screen more complicated. The future of smartphone technologies is peaking in development and users are unforgiving with lagging systems. If users can’t read your content, your design doesn’t work. ), you name it, they’re on their phones. A well designed app that offers an unmatched user experience is a must for this purpose. Ashni Sharma is an application developer working with AppsChopper. Cluttering your interface overloads your user with too much information: every added button, image, and line of text make the screen more complicated. Build your products with a user-centered approach by testing with real users. In order to keep up with the fast advancements in technology and shift to smartphone adoption, designing mobile experiences needs to implement usability principles. Here are 10 UX design principles that I think are key for creating really great mobile user experiences. The limited space available on a small screen makes every additional element you add overwhelming to your users. A fundamental design principle for mobile phones is to include only necessary information. Users … Accessibility behavioural features should be made available to users to make navigation and use easier. Test different features, layouts and variations of your designs to see what works best. Like really, really short. When it’s done poorly, users can’t get past it to efficiently use a product. Minimize the user's memory load by making elements, actions, and options visible. One of these features is high resolution HD screen and the apps can make the most of it by using the high definition images so that the users are mesmerized by the appearance. Hand positions should be kept in mind when placing controls on a mobile design. Before we go any further, let’s define six of the most common user interface design principles; the structure principle, the simplicity principle, the visibility principle, the feedback principle, the tolerance principle, and finally, the reuse principle. These UI design principles will go a long way in helping you design the apps with market, end users and overall app performance taken into account. Smartphones have become a go-to source for all sorts of information because they’re easily accessible anytime, anywhere. When it comes to creating online journeys the ultimate goal is to create a seamless experience, across all devices. It can be achieved by taking into account all the performance factors and creating the design around them. But that’s easier said than done. Developers work hard to make the application work—customers just expect it to work and their perception of the software centers around this requirement. Spacing and layout are also important to improve legibility. If you wanted to design a great and fully-functional mobile application interface, you should consider design principles that are hugely important. While choosing these metaphors, it must be ensured that they must not be obsolete or else the new age users will not be able to recognize the icons leading to confusion. An app can suggest a course of action or warn about dangerous consequences, but it’s usually a mistake for the app to take over the decision-making. A new app in the market has to compete with the already established ones, which makes the battle a lot more arduous. ALL RIGHTS RESERVED. User journeys should be logical  enough that a task is accomplished within a single app. There are obviously certain limitations when you are designing the interface for an app, these have to be dealt with care. WC3’s Web Content Accessibility Guidelines gives contrast ratio recommendations for images and text. Small touch targets can be frustrating because they require more accuracy and are prone to errors. Award Winning Web & Mobile UX, Usability & Ecommerce Consultancy | KSA, UAE, UK, 10 Mobile UX Design Principles You Should Know, Statistics forecast the number of global smartphone users to reach, In order to trigger positive reactions, you have to satisfy the. The app has to strike the right chord with the sensibilities, preferences, and expectations of the app users and offer an user experience which is not only new but fresh. In order to trigger positive reactions, you have to satisfy the basic usability principles of interface design. When users interact with the apps, they want them to be relevant, smooth and most importantly high on usability. The original principles have been revisited for mobile to further integrate human-centered design and user needs—including clear … There is an intense competition in the mobile app industry, and you have to be on your toes to stay relevant and popular. One of the challenges of mobile design is to fit a lot of information on a small user interface. Users are always looking for shortcuts and efficient ways to get things done. Synchronization across devices is a key priority for creating seamless experiences. Performance of an app is considered the sole responsibility of the developer and design team considers this factor quite late in the designing phase. User Compatibility:“Know the user” is the fundamental principle in interface design as no users are alike & they think, feel & behave differently compared to the developer. If it takes too much time or effort to discover how to navigate through your product, chances are you’re just going to lose your users. There are two fundamental approaches to usability. Just as a bridge is designed to withstand the wind and traffic, keeping its aesthetics intact, an app too needs to be built in a similar fashion. The earlier you discover your problems, the easier and cheaper it is to fix them. App Icon. Interaction Design. This is especially true if you develop retail software, or something that will be used by non-technical people. These few seconds have to be made counted or your prospective user will look for the alternatives that are available in large numbers. Efficiency: How quickly users perform basic tasks once they’ve learned the design. [paypalsubmit class:primary-button email:mahmoud-facilitator@uxbert.com itemamount:000_11ecom_300 itemname:000_11ecom_300_name return_url:http://uxbert.com/ cancel_url:http://uxbert.com/ sandbox]. Integrate status and other types of feedback into your interface without disrupting the user’s workflow. 8 seconds to be exact. Before you start to code the app, you need to be sure about the audience that you intend to target. Design elements like layouts, animations and graphics have performance implications and hence, they need to be dealt by those designers who are masters of their craft. Smartphones are laced with a plethora of amazing features that must be made most of. It is one of the main components... 3. Accessing the same amount of information from a desktop on smartphones requires a higher interaction cost because of screen size. Users should be able to make decisions to personalize their journeys. Less is more. Secondary content should be available through a menu. If action buttons are too close to each other, you risk the user making undesired actions leading to frustration. For instance, a user while shopping online wants the products to be displayed in high resolution and a simple checkout process that memorizes the payment methods and other details. Required fields are marked *, You may use these HTML tags and attributes:
. Focus on key user goals by reducing friction, minimizing steps and page loads to decrease interaction time. Allow users to make decisions to personalize their journeys. The user should not have to remember information from one part of the interface to another. Fill in your details below and one of our team members will be in touch with you via email or phone call soon to provide you with further details. In order to elicit positive reactions, you have to satisfy the basic usability principles of interface design. Like really, really short. The design of your app icon is a major factor... 2. Uniqueness. Learnability: How easily first-time users complete basic tasks. The best apps find the correct balance between … One of our team members will be in touch with you via email or phone call soon to provide you with further details. In short, when they encounter a button, they will think this button will be triggered to meet their needs. Users lack the patience to try to work through complex steps to get what they want. A lot of care should be exercised while choosing the content and features on every screen of the app. You can enhance both the perceived performance and the actual elements in the app. The 10 most important interaction design principles are-UX: Match user experience and expectations; Consistent design: Maintain consistency throughout the application; Functionality: Follow functional minimalism; Cognition: Reduce cognitive loads/mental pressure to understand the application; Engagement: Design interactively such that it keeps the user engaged. The 10 principles of mobile interface design ART AND DESIGN INSPIRATION By Creative Bloq Staff April 15, 2012 Web design Based on his workshops, mobile consultant Jonathan Stark compiles the top principles of mobile interface design and explains how to take your mobile app from concept to completed design . The kind of user experience that entices the users and keep them glued to the app requires designers who have crisp understanding of the front-end programming and are aware of the design’s purpose. This is one of the crucial mistakes that is often committed and has serious repercussions. When it comes to creating online journeys the ultimate goal is to create a seamless experience, across all devices. For example, icons of power button, red button for recording and various others are used to save space and enhance the look and feel of the app. The look and feel of the app should be completely modified to honor the different platforms. Cut Out The Clutter. We have compiled a detailed dossier of all the mobile app design principles and best practices you can follow to make your app deliver the sleekest, most efficient user experience, and keep them coming back every time they need a service you offer. Just like the design of the car affects its aerodynamics, the design of the app has tremendous impact on the performance of the app. The user interface of the app must be a manifestation of the brand, and the users must connect to it. When you are out with a product in hand, a detailed study of the market must precede it, and product design must be in sync with the information gathered. Adversely, an unnecessarily large font size results in awkward breaks and hyphenation that take longer to read. Email us at hello@uxbert.com and let us show you why we’re an award winning company. Make content accessible even without an online connection and provide alternative paths to avoid dead-ends. It is especially important to space out contradicting action buttons, such as the save and delete buttons to avoid errors. If users can’t read your content, there’s no point in offering content in the first place. The user doesn’t realize it, but the flow is a natural process and the user feels ‘right’ using it. Indoors, outdoors, in planes, trains, buses, cars, underground, overground (you get it right? People like to feel like they’re in control of their actions. Relieve users by providing autocomplete, recent search history and location detection to reduce data entry requirements and accelerate the experience. Help them reduce typing required by shortening forms, removing unnecessary fields and using ‘remember me’ options for future use. © 2018 Growthword Digital Private Limited. Tips 1. The user interface design should also be in sync with it and must be able to solve the problem without making things very complex. This will surely help your app establish itself and enhance the brand value. But how big can you make them with only a small amount of screen space? Making things easier for your users means not forcing them to learn new representations or toolsets for each task. Use a visual approach to map the entire customer journey and keeping the larger picture in mind, use the content-first method. This guest column is by Ashni Sharma, ‎Sr. Optimization of the UI flows and other elements of the app make the app faster and more usable. People use their thumbs more often than any other finger while using their smartphones. Users are always looking for shortcuts and efficient ways to get things done. A good rule of thumb is to use 30–40 characters per line for mobile. Apple’s iPhone Human Interface Guidelines suggest a minimum target size of, The strategy for optimal mobile typography is a. to read for any screen. It makes users feel that their workflow isn’t interrupted and aren’t burdened by having to make the effort of transferring data. A famous saying by Antoine de Saint-Exupéry ca… Design is more than just good aesthetics. #Fundingwire – YuppTV Raises $50M in Series B & More. But if this button get triggered in some other operation ratner than user's expectation, it must be a bad design. Developers must be aware of the needs of the end-user throughout the entire software design process. These 14 principles of user interface design will make your users — the people who use your product, website, or app — happy. As you design the user interface, it is important to keep in mind the interactions that take place between the human cognition and the screen you’re designing for. Note that there is considerable overlap between Nielsen and Molich's heuristics and Ben Shneiderman’s 'eight golden rules'. These are one of the most used heuristics for User Interface Design. Adversely, an unnecessarily large font size results in awkward breaks and hyphenation that take longer to read. Reducing the length of the thinking process by eliminating confusion is also a sure bet when it comes to improving user experience. At the end of the day, we’re all human and make mistakes, even when target size and spacing are scaled properly. If you are making a technically superior feature, couple it with a great design and ensure the utmost smoothness in the feature. User Control. Elements that can be optimized to make the app faster are images, videos, maps, and other content. Errors: The amount and severity of errors users make and how easily they can correct them. Statistics forecast the number of global smartphone users to reach 6.1 billion by 2020. It makes users feel that their workflow isn’t interrupted and aren’t burdened by having to make the effort of transferring data. These 10 rules of thumb further iterate upon Shneiderman’s eight golden rules 4 years after Shneiderm… The first impression should be therefore, imposing and must offer some unique elements that no other app does. The user interface should be designed accordingly. The image of the busy professional racing through the airport with a bag in one hand and smartphone... 03. 10 Mobile UX Design Principles You Should Know 1. 2. The users do not want to see a lot of options and content in the app as it causes distraction. But designing a usable and enjoyable mobile experience is more than just good aesthetics. 1. Users appreciate smooth interactions with designs and are satisfied when their needs are met effortlessly. Make Navigation Intuitive. Not less than 7-10 mm. To keep your users engaged, you have to keep the interface at a minimum. Because of the differences between mobile and desktop, it’s imperative to get yourself into a mobile... 02. Make Interface Elements Clearly Visible. Using similar layouts and design elements can also lead to performance issues. Every mobile platform is distinct in appearance and has some design peculiarities that define it. UI should reflect the brand story. Hence, tiring the reader.