Computer Software Description

Download Computer Software Description full books in PDF, epub, and Kindle. Read online Computer Software Description ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!

Code

Author : Charles Petzold
Publisher : Microsoft Press
ISBN 13 : 0137909292
Total Pages : 563 pages
Book Rating : 4.1/5 (379 download)

DOWNLOAD NOW!

Book Synopsis Code by : Charles Petzold

Download or read book Code written by Charles Petzold and published by Microsoft Press. This book was released on 2022-08-02 with total page 563 pages. Available in PDF, EPUB and Kindle. Book excerpt: The classic guide to how computers work, updated with new chapters and interactive graphics "For me, Code was a revelation. It was the first book about programming that spoke to me. It started with a story, and it built up, layer by layer, analogy by analogy, until I understood not just the Code, but the System. Code is a book that is as much about Systems Thinking and abstractions as it is about code and programming. Code teaches us how many unseen layers there are between the computer systems that we as users look at every day and the magical silicon rocks that we infused with lightning and taught to think." - Scott Hanselman, Partner Program Director, Microsoft, and host of Hanselminutes Computers are everywhere, most obviously in our laptops and smartphones, but also our cars, televisions, microwave ovens, alarm clocks, robot vacuum cleaners, and other smart appliances. Have you ever wondered what goes on inside these devices to make our lives easier but occasionally more infuriating? For more than 20 years, readers have delighted in Charles Petzold's illuminating story of the secret inner life of computers, and now he has revised it for this new age of computing. Cleverly illustrated and easy to understand, this is the book that cracks the mystery. You'll discover what flashlights, black cats, seesaws, and the ride of Paul Revere can teach you about computing, and how human ingenuity and our compulsion to communicate have shaped every electronic device we use. This new expanded edition explores more deeply the bit-by-bit and gate-by-gate construction of the heart of every smart device, the central processing unit that combines the simplest of basic operations to perform the most complex of feats. Petzold's companion website, CodeHiddenLanguage.com, uses animated graphics of key circuits in the book to make computers even easier to comprehend. In addition to substantially revised and updated content, new chapters include: Chapter 18: Let's Build a Clock! Chapter 21: The Arithmetic Logic Unit Chapter 22: Registers and Busses Chapter 23: CPU Control Signals Chapter 24: Jumps, Loops, and Calls Chapter 28: The World Brain From the simple ticking of clocks to the worldwide hum of the internet, Code reveals the essence of the digital revolution.

Information Systems for Business and Beyond

Author : David T. Bourgeois
Publisher :
ISBN 13 :
Total Pages : 167 pages
Book Rating : 4.:/5 (1 download)

DOWNLOAD NOW!

Book Synopsis Information Systems for Business and Beyond by : David T. Bourgeois

Download or read book Information Systems for Business and Beyond written by David T. Bourgeois and published by . This book was released on 2014 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Information Systems for Business and Beyond introduces the concept of information systems, their use in business, and the larger impact they are having on our world."--BC Campus website.

Guide to the Software Engineering Body of Knowledge (Swebok(r))

Author : IEEE Computer Society
Publisher :
ISBN 13 : 9780769551661
Total Pages : 348 pages
Book Rating : 4.5/5 (516 download)

DOWNLOAD NOW!

Book Synopsis Guide to the Software Engineering Body of Knowledge (Swebok(r)) by : IEEE Computer Society

Download or read book Guide to the Software Engineering Body of Knowledge (Swebok(r)) written by IEEE Computer Society and published by . This book was released on 2014 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the Guide to the Software Engineering Body of Knowledge (SWEBOK(R) Guide), the IEEE Computer Society establishes a baseline for the body of knowledge for the field of software engineering, and the work supports the Society's responsibility to promote the advancement of both theory and practice in this field. It should be noted that the Guide does not purport to define the body of knowledge but rather to serve as a compendium and guide to the knowledge that has been developing and evolving over the past four decades. Now in Version 3.0, the Guide's 15 knowledge areas summarize generally accepted topics and list references for detailed information. The editors for Version 3.0 of the SWEBOK(R) Guide are Pierre Bourque (Ecole de technologie superieure (ETS), Universite du Quebec) and Richard E. (Dick) Fairley (Software and Systems Engineering Associates (S2EA)).

Postphenomenology

Author : Don Ihde
Publisher : Northwestern University Press
ISBN 13 : 0810112752
Total Pages : 176 pages
Book Rating : 4.8/5 (11 download)

DOWNLOAD NOW!

Book Synopsis Postphenomenology by : Don Ihde

Download or read book Postphenomenology written by Don Ihde and published by Northwestern University Press. This book was released on 1995-06-21 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Postphenomenology is a fascinating investigation of the relationships between global culture and technology. The impressive range of subjects to which Don Ihde applies his skill as a phenomenologist is unified by what he describes as "a concern which arises with respect to one of the now major trends of Euro-American philosophy--its textism." He adds, "I show my worries to be less about the loss of subjects or authors, than I do about [there] not being bodies or perceivers."

Computer Systems and Software Engineering: Concepts, Methodologies, Tools, and Applications

Author : Management Association, Information Resources
Publisher : IGI Global
ISBN 13 : 1522539247
Total Pages : 2124 pages
Book Rating : 4.5/5 (225 download)

DOWNLOAD NOW!

Book Synopsis Computer Systems and Software Engineering: Concepts, Methodologies, Tools, and Applications by : Management Association, Information Resources

Download or read book Computer Systems and Software Engineering: Concepts, Methodologies, Tools, and Applications written by Management Association, Information Resources and published by IGI Global. This book was released on 2017-12-01 with total page 2124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professionals in the interdisciplinary field of computer science focus on the design, operation, and maintenance of computational systems and software. Methodologies and tools of engineering are utilized alongside computer applications to develop efficient and precise information databases. Computer Systems and Software Engineering: Concepts, Methodologies, Tools, and Applications is a comprehensive reference source for the latest scholarly material on trends, techniques, and uses of various technology applications and examines the benefits and challenges of these computational developments. Highlighting a range of pertinent topics such as utility computing, computer security, and information systems applications, this multi-volume book is ideally designed for academicians, researchers, students, web designers, software developers, and practitioners interested in computer systems and software engineering.

Software Development Techniques for Constructive Information Systems Design

Author : Buragga, Khalid A.
Publisher : IGI Global
ISBN 13 : 1466636807
Total Pages : 480 pages
Book Rating : 4.4/5 (666 download)

DOWNLOAD NOW!

Book Synopsis Software Development Techniques for Constructive Information Systems Design by : Buragga, Khalid A.

Download or read book Software Development Techniques for Constructive Information Systems Design written by Buragga, Khalid A. and published by IGI Global. This book was released on 2013-03-31 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Software development and information systems design have a unique relationship, but are often discussed and studied independently. However, meticulous software development is vital for the success of an information system. Software Development Techniques for Constructive Information Systems Design focuses the aspects of information systems and software development as a merging process. This reference source pays special attention to the emerging research, trends, and experiences in this area which is bound to enhance the reader's understanding of the growing and ever-adapting field. Academics, researchers, students, and working professionals in this field will benefit from this publication's unique perspective.

Computer Science

Author : Edward K. Blum
Publisher : Springer Science & Business Media
ISBN 13 : 1461411688
Total Pages : 470 pages
Book Rating : 4.4/5 (614 download)

DOWNLOAD NOW!

Book Synopsis Computer Science by : Edward K. Blum

Download or read book Computer Science written by Edward K. Blum and published by Springer Science & Business Media. This book was released on 2011-12-02 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer Science: The Hardware, Software and Heart of It focuses on the deeper aspects of the two recognized subdivisions of Computer Science, Software and Hardware. These subdivisions are shown to be closely interrelated as a result of the stored-program concept. Computer Science: The Hardware, Software and Heart of It includes certain classical theoretical computer science topics such as Unsolvability (e.g. the halting problem) and Undecidability (e.g. Godel’s incompleteness theorem) that treat problems that exist under the Church-Turing thesis of computation. These problem topics explain inherent limits lying at the heart of software, and in effect define boundaries beyond which computer science professionals cannot go beyond. Newer topics such as Cloud Computing are also covered in this book. After a survey of traditional programming languages (e.g. Fortran and C++), a new kind of computer Programming for parallel/distributed computing is presented using the message-passing paradigm which is at the heart of large clusters of computers. This leads to descriptions of current hardware platforms for large-scale computing, such as clusters of as many as one thousand which are the new generation of supercomputers. This also leads to a consideration of future quantum computers and a possible escape from the Church-Turing thesis to a new computation paradigm. The book’s historical context is especially helpful during this, the centenary of Turing's birth. Alan Turing is widely regarded as the father of Computer Science, since many concepts in both the hardware and software of Computer Science can be traced to his pioneering research. Turing was a multi-faceted mathematician-engineer and was able to work on both concrete and abstract levels. This book shows how these two seemingly disparate aspects of Computer Science are intimately related. Further, the book treats the theoretical side of Computer Science as well, which also derives from Turing's research. Computer Science: The Hardware, Software and Heart of It is designed as a professional book for practitioners and researchers working in the related fields of Quantum Computing, Cloud Computing, Computer Networking, as well as non-scientist readers. Advanced-level and undergraduate students concentrating on computer science, engineering and mathematics will also find this book useful.

The Mathematical-Function Computation Handbook

Author : Nelson H.F. Beebe
Publisher : Springer
ISBN 13 : 3319641107
Total Pages : 1145 pages
Book Rating : 4.3/5 (196 download)

DOWNLOAD NOW!

Book Synopsis The Mathematical-Function Computation Handbook by : Nelson H.F. Beebe

Download or read book The Mathematical-Function Computation Handbook written by Nelson H.F. Beebe and published by Springer. This book was released on 2017-08-20 with total page 1145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This highly comprehensive handbook provides a substantial advance in the computation of elementary and special functions of mathematics, extending the function coverage of major programming languages well beyond their international standards, including full support for decimal floating-point arithmetic. Written with clarity and focusing on the C language, the work pays extensive attention to little-understood aspects of floating-point and integer arithmetic, and to software portability, as well as to important historical architectures. It extends support to a future 256-bit, floating-point format offering 70 decimal digits of precision. Select Topics and Features: references an exceptionally useful, author-maintained MathCW website, containing source code for the book’s software, compiled libraries for numerous systems, pre-built C compilers, and other related materials; offers a unique approach to covering mathematical-function computation using decimal arithmetic; provides extremely versatile appendices for interfaces to numerous other languages: Ada, C#, C++, Fortran, Java, and Pascal; presupposes only basic familiarity with computer programming in a common language, as well as early level algebra; supplies a library that readily adapts for existing scripting languages, with minimal effort; supports both binary and decimal arithmetic, in up to 10 different floating-point formats; covers a significant portion (with highly accurate implementations) of the U.S National Institute of Standards and Technology’s 10-year project to codify mathematical functions. This highly practical text/reference is an invaluable tool for advanced undergraduates, recording many lessons of the intermingled history of computer hardw are and software, numerical algorithms, and mathematics. In addition, professional numerical analysts and others will find the handbook of real interest and utility because it builds on research by the mathematical software community over the last four decades.

Software Architecture in Practice

Author : Len Bass
Publisher : Addison-Wesley Professional
ISBN 13 : 9780321154958
Total Pages : 572 pages
Book Rating : 4.1/5 (549 download)

DOWNLOAD NOW!

Book Synopsis Software Architecture in Practice by : Len Bass

Download or read book Software Architecture in Practice written by Len Bass and published by Addison-Wesley Professional. This book was released on 2003 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the eagerly-anticipated revision to one of the seminal books in the field of software architecture which clearly defines and explains the topic.

Documenting Software Architectures

Author : Paul Clements
Publisher : Pearson Education
ISBN 13 : 0132488590
Total Pages : 651 pages
Book Rating : 4.1/5 (324 download)

DOWNLOAD NOW!

Book Synopsis Documenting Software Architectures by : Paul Clements

Download or read book Documenting Software Architectures written by Paul Clements and published by Pearson Education. This book was released on 2010-10-05 with total page 651 pages. Available in PDF, EPUB and Kindle. Book excerpt: Software architecture—the conceptual glue that holds every phase of a project together for its many stakeholders—is widely recognized as a critical element in modern software development. Practitioners have increasingly discovered that close attention to a software system’s architecture pays valuable dividends. Without an architecture that is appropriate for the problem being solved, a project will stumble along or, most likely, fail. Even with a superb architecture, if that architecture is not well understood or well communicated the project is unlikely to succeed. Documenting Software Architectures, Second Edition, provides the most complete and current guidance, independent of language or notation, on how to capture an architecture in a commonly understandable form. Drawing on their extensive experience, the authors first help you decide what information to document, and then, with guidelines and examples (in various notations, including UML), show you how to express an architecture so that others can successfully build, use, and maintain a system from it. The book features rules for sound documentation, the goals and strategies of documentation, architectural views and styles, documentation for software interfaces and software behavior, and templates for capturing and organizing information to generate a coherent package. New and improved in this second edition: Coverage of architectural styles such as service-oriented architectures, multi-tier architectures, and data models Guidance for documentation in an Agile development environment Deeper treatment of documentation of rationale, reflecting best industrial practices Improved templates, reflecting years of use and feedback, and more documentation layout options A new, comprehensive example (available online), featuring documentation of a Web-based service-oriented system Reference guides for three important architecture documentation languages: UML, AADL, and SySML

The Secret Life of Programs

Author : Jonathan E. Steinhart
Publisher : No Starch Press
ISBN 13 : 1593279701
Total Pages : 505 pages
Book Rating : 4.5/5 (932 download)

DOWNLOAD NOW!

Book Synopsis The Secret Life of Programs by : Jonathan E. Steinhart

Download or read book The Secret Life of Programs written by Jonathan E. Steinhart and published by No Starch Press. This book was released on 2019-08-06 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: A primer on the underlying technologies that allow computer programs to work. Covers topics like computer hardware, combinatorial logic, sequential logic, computer architecture, computer anatomy, and Input/Output. Many coders are unfamiliar with the underlying technologies that make their programs run. But why should you care when your code appears to work? Because you want it to run well and not be riddled with hard-to-find bugs. You don't want to be in the news because your code had a security problem. Lots of technical detail is available online but it's not organized or collected into a convenient place. In The Secret Life of Programs, veteran engineer Jonathan E. Steinhart explores--in depth--the foundational concepts that underlie the machine. Subjects like computer hardware, how software behaves on hardware, as well as how people have solved problems using technology over time. You'll learn: How the real world is converted into a form that computers understand, like bits, logic, numbers, text, and colors The fundamental building blocks that make up a computer including logic gates, adders, decoders, registers, and memory Why designing programs to match computer hardware, especially memory, improves performance How programs are converted into machine language that computers understand How software building blocks are combined to create programs like web browsers Clever tricks for making programs more efficient, like loop invariance, strength reduction, and recursive subdivision The fundamentals of computer security and machine intelligence Project design, documentation, scheduling, portability, maintenance, and other practical programming realities. Learn what really happens when your code runs on the machine and you'll learn to craft better, more efficient code.

The Architecture of Computer Hardware, Systems Software, and Networking

Author : Irv Englander
Publisher : John Wiley & Sons
ISBN 13 : 1119495202
Total Pages : 73 pages
Book Rating : 4.1/5 (194 download)

DOWNLOAD NOW!

Book Synopsis The Architecture of Computer Hardware, Systems Software, and Networking by : Irv Englander

Download or read book The Architecture of Computer Hardware, Systems Software, and Networking written by Irv Englander and published by John Wiley & Sons. This book was released on 2021-04-06 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Architecture of Computer Hardware, Systems Software and Networking is designed help students majoring in information technology (IT) and information systems (IS) understand the structure and operation of computers and computer-based devices. Requiring only basic computer skills, this accessible textbook introduces the basic principles of system architecture and explores current technological practices and trends using clear, easy-to-understand language. Throughout the text, numerous relatable examples, subject-specific illustrations, and in-depth case studies reinforce key learning points and show students how important concepts are applied in the real world. This fully-updated sixth edition features a wealth of new and revised content that reflects today’s technological landscape. Organized into five parts, the book first explains the role of the computer in information systems and provides an overview of its components. Subsequent sections discuss the representation of data in the computer, hardware architecture and operational concepts, the basics of computer networking, system software and operating systems, and various interconnected systems and components. Students are introduced to the material using ideas already familiar to them, allowing them to gradually build upon what they have learned without being overwhelmed and develop a deeper knowledge of computer architecture.

Computer Games and Software Engineering

Author : Kendra M. L. Cooper
Publisher : CRC Press
ISBN 13 : 1482226693
Total Pages : 304 pages
Book Rating : 4.4/5 (822 download)

DOWNLOAD NOW!

Book Synopsis Computer Games and Software Engineering by : Kendra M. L. Cooper

Download or read book Computer Games and Software Engineering written by Kendra M. L. Cooper and published by CRC Press. This book was released on 2015-05-08 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer games represent a significant software application domain for innovative research in software engineering techniques and technologies. Game developers, whether focusing on entertainment-market opportunities or game-based applications in non-entertainment domains, thus share a common interest with software engineers and developers on how to

Computer Architecture

Author : John Y. Hsu
Publisher : CRC Press
ISBN 13 : 9781420041101
Total Pages : 462 pages
Book Rating : 4.0/5 (411 download)

DOWNLOAD NOW!

Book Synopsis Computer Architecture by : John Y. Hsu

Download or read book Computer Architecture written by John Y. Hsu and published by CRC Press. This book was released on 2017-12-19 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the new developments in computer architecture, fairly recent publications can quickly become outdated. Computer Architecture: Software Aspects, Coding, and Hardware takes a modern approach. This comprehensive, practical text provides that critical understanding of a central processor by clearly detailing fundamentals, and cutting edge design features. With its balanced software/hardware perspective and its description of Pentium processors, the book allows readers to acquire practical PC software experience. The text presents a foundation-level set of ideas, design concepts, and applications that fully meet the requirements of computer organization and architecture courses. The book features a "bottom up" computer design approach, based upon the author's thirty years experience in both academe and industry. By combining computer engineering with electrical engineering, the author describes how logic circuits are designed in a CPU. The extensive coverage of a micprogrammed CPU and new processor design features gives the insight of current computer development. Computer Architecture: Software Aspects, Coding, and Hardware presents a comprehensive review of the subject, from beginner to advanced levels. Topics include: o Two's complement numbers o Integer overflow o Exponent overflow and underflow o Looping o Addressing modes o Indexing o Subroutine linking o I/O structures o Memory mapped I/O o Cycle stealing o Interrupts o Multitasking o Microprogrammed CPU o Multiplication tree o Instruction queue o Multimedia instructions o Instruction cache o Virtual memory o Data cache o Alpha chip o Interprocessor communications o Branch prediction o Speculative loading o Register stack o JAVA virtual machine o Stack machine principles

Scene of the Cybercrime

Author : Debra Littlejohn Shinder
Publisher : Elsevier
ISBN 13 : 0080486991
Total Pages : 745 pages
Book Rating : 4.0/5 (84 download)

DOWNLOAD NOW!

Book Synopsis Scene of the Cybercrime by : Debra Littlejohn Shinder

Download or read book Scene of the Cybercrime written by Debra Littlejohn Shinder and published by Elsevier. This book was released on 2008-07-21 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: When it comes to computer crimes, the criminals got a big head start. But the law enforcement and IT security communities are now working diligently to develop the knowledge, skills, and tools to successfully investigate and prosecute Cybercrime cases. When the first edition of "Scene of the Cybercrime" published in 2002, it was one of the first books that educated IT security professionals and law enforcement how to fight Cybercrime. Over the past 5 years a great deal has changed in how computer crimes are perpetrated and subsequently investigated. Also, the IT security and law enforcement communities have dramatically improved their ability to deal with Cybercrime, largely as a result of increased spending and training. According to the 2006 Computer Security Institute's and FBI's joint Cybercrime report: 52% of companies reported unauthorized use of computer systems in the prior 12 months. Each of these incidents is a Cybecrime requiring a certain level of investigation and remediation. And in many cases, an investigation is mandates by federal compliance regulations such as Sarbanes-Oxley, HIPAA, or the Payment Card Industry (PCI) Data Security Standard. Scene of the Cybercrime, Second Edition is a completely revised and updated book which covers all of the technological, legal, and regulatory changes, which have occurred since the first edition. The book is written for dual audience; IT security professionals and members of law enforcement. It gives the technical experts a little peek into the law enforcement world, a highly structured environment where the "letter of the law" is paramount and procedures must be followed closely lest an investigation be contaminated and all the evidence collected rendered useless. It also provides law enforcement officers with an idea of some of the technical aspects of how cyber crimes are committed, and how technology can be used to track down and build a case against the criminals who commit them. Scene of the Cybercrime, Second Editions provides a roadmap that those on both sides of the table can use to navigate the legal and technical landscape to understand, prevent, detect, and successfully prosecute the criminal behavior that is as much a threat to the online community as "traditional" crime is to the neighborhoods in which we live. Also included is an all new chapter on Worldwide Forensics Acts and Laws. - Companion Web site provides custom tools and scripts, which readers can download for conducting digital, forensic investigations - Special chapters outline how Cybercrime investigations must be reported and investigated by corporate IT staff to meet federal mandates from Sarbanes Oxley, and the Payment Card Industry (PCI) Data Security Standard - Details forensic investigative techniques for the most common operating systems (Windows, Linux and UNIX) as well as cutting edge devices including iPods, Blackberries, and cell phones

Effective Software Project Management

Author : Robert K. Wysocki
Publisher : Wiley + ORM
ISBN 13 : 0470446536
Total Pages : 547 pages
Book Rating : 4.4/5 (74 download)

DOWNLOAD NOW!

Book Synopsis Effective Software Project Management by : Robert K. Wysocki

Download or read book Effective Software Project Management written by Robert K. Wysocki and published by Wiley + ORM. This book was released on 2010-09-29 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why another book on software project management? For some time, the fields of project management, computer science, and software development have been growing rapidly and concurrently. Effective support for the enterprise demands the merging of these efforts into a coordinated discipline, one that incorporates best practices from both systems development and project management life cycles. Robert K. Wysocki creates that discipline in this book--a ready reference for professionals and consultants as well as a textbook for students of computer information systems and project management. By their very nature, software projects defy a "one size fits all" approach. In these pages you will learn to apply best-practice principles while maintaining the flexibility that's essential for successful software development. Learn how to make the planning process fit the need * Understand how and why software development must be planned on a certainty-to-uncertainty continuum * Categorize your projects on a four-quadrant model * Learn when to use each of the five SDPM strategies--Linear, Incremental, Iterative, Adaptive, and Extreme * Explore the benefits of each strategic model and what types of projects it supports best * Recognize the activities that go into the Scoping, Planning, Launching, Monitoring/Controlling, and Closing phases of each strategy * Apply this knowledge to the specific projects you manage * Get a clear picture of where you are and how to get where you want to go

Inside Computer Music

Author : Michael Clarke
Publisher :
ISBN 13 : 0190659645
Total Pages : 433 pages
Book Rating : 4.1/5 (96 download)

DOWNLOAD NOW!

Book Synopsis Inside Computer Music by : Michael Clarke

Download or read book Inside Computer Music written by Michael Clarke and published by . This book was released on 2020 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inside Computer Music is an investigation of how new technological developments have influenced the creative possibilities of composers of computer music in the last 50 years. This book combines detailed research into the development of computer music techniques with nine case studies that analyze key works in the musical and technical development of computer music. The book's companion website offers demonstration videos of the techniques used and downloadable software. There, readers can view interviews and test emulations of the software used by the composers for themselves. The software also presents musical analyses of each of the nine case studies to enable readers to engage with the musical structure aurally and interactively.