cyanic-selkie/wikianc huggingface dataset:
স্বামী আত্মজানন্দ
স্বামী আত্মজানন্দ যার পূর্ব নাম ছিল স্টুয়ার্ট এল্কম্যান একজন রামকৃষ্ণ মিশনের সন্ন্যাসী। তিনি রামকৃষ্ণ মিশনে ১৯৮১ সালে যোগদান করেন। তিনি অরিয়েণ্টাল স্টাডিজ এর উপর পেনিনসিলভানিয়া বিশ্ববিদ্যালয় থেকে পি.এইস.ডি ডিগ্রী সম্পন্ন করেন। তিনি বর্তমানে ওয়াশিংটন ডিসি তে বেদান্ত সেন্টারে কর্মরত আছেন।
তিনি গৌড়ীয় বৈষ্ণব সম্প্রদায়ের উপর একটি বই লেখেন সন্ন্যাস গ্রহণের পূর্বে। যেটি ১৯৮৬ সালে প্রকাশিত হয়।
মালয়েশিয়া জাতীয় ক্রিকেট দল
মালয়েশিয়া জাতীয় ক্রিকেট দল আন্তর্জাতিক ক্রিকেট খেলায় মালয়েশিয়ার জাতীয় পর্যায়ে প্রতিনিধিত্বকারী ক্রিকেট দল। দলটি ১৯৬৭ সাল থেকে আন্তর্জাতিক ক্রিকেট কাউন্সিলের সহযোগী সদস্য হিসেবে রয়েছে।
১৮৮০-এর দশকে বর্তমান মালয়েশিয়ায় ক্রিকেট খেলার প্রচলন ঘটে। ১৮৮৪ সালে ব্রিটিশদের মাধ্যমে রয়্যাল সেলাঙ্গার ক্লাব (আরএসসি) প্রতিষ্ঠিত হয় যা বর্তমান মালয়েশিয়ার প্রথম ক্রিকেট ক্লাব। ১৮৫২ সালে প্রতিষ্ঠিত সিঙ্গাপুর ক্রিকেট ক্লাব সাবেক মালয়ান ক্রিকেট সংস্থার অনুমোদনকৃত ক্লাবরূপে ঐ অঞ্চলের প্রাচীনতম ক্রিকেট ক্লাব।
ইতিহাস
লিপিবদ্ধকৃত প্রথম খেলাটি ১৮৮৭ সালে সেলাঙ্গর ও মালাক্কার মধ্যে অনুষ্ঠিত হয়েছিল। ১৮৯১ সালে সেলাঙ্গর-সিঙ্গাপুরের মধ্যকার সিরিজ অনুষ্ঠিত হয়। বিংশ শতাব্দীর প্রথমার্ধে জোহরে ক্রিকেট খেলা অনুষ্ঠিত হয়। কিন্তু আনুষ্ঠানিকভাবে লিপিবদ্ধকৃত ক্রিকেট খেলাটি সফরকারী অস্ট্রেলিয়ার সাথে আয়োজন করা হয়েছিল। ১৯২৭ অনুষ্ঠিত এ সফরে অস্ট্রেলিয়ার নেতৃত্ব দিয়েছিলেন সি. জি. ম্যাককার্টনি। ব্রিটিশ সময়কালে মালয়েশিয়ার পেনাংও ঐতিহাসিক ক্রিকেট আয়োজনের স্থান হিসেবে উল্লেখযোগ্য। ১৯০০-এর প্রথমার্ধে পেনাং স্পোর্ট ক্লাব প্রতিষ্ঠিত হয়। ৬ জুন, ১৯২৭ তারিখে মালয় ৩৯ রানের ব্যবধানে অস্ট্রেলিয়াকে পরাভূত করেছিল। মালয়েশিয়ায় জন্মগ্রহণকারী লাল সিং ভারতের হয়ে ১৯৩২ সালে ইংল্যান্ডের বিপক্ষে লর্ডসে টেস্ট ক্রিকেট খেলে প্রথম মালয়েশিয়ানের গৌরব অর্জন করেন। ১৯৪৮ সালে মালয়ান ক্রিকেট সংস্থা প্রতিষ্ঠিত হবার পর ক্রিকেটের বিস্তৃতি ঘটতে শুরু করে। সাবাহ, সারাওয়াক, সিঙ্গাপুর প্রভৃতি আঞ্চলিক ক্রিকেট সংস্থা পরবর্তীকালে ১৯৬৩ সালে প্রতিষ্ঠিত মালয়েশিয়ান ক্রিকেট সংস্থা গঠনের পর যোগদান করে। কিন্তু ১৯৬৫ সালে সিঙ্গাপুরের স্বাধীনতা অর্জনের ফলে তারা সংস্থা ত্যাগ করে।
১৯৭০ সালে মালয়েশিয়ায় প্রথম জাতীয় পর্যায়ের দল গঠিত হয়। এর তিনবছর পূর্বে দলটি আইসিসি’র সহযোগী সদস্যের মর্যাদা পায়। টনি লুইসের নেতৃত্বাধীন মেরিলেবোন ক্রিকেট ক্লাবের বিপক্ষে ২-দিনের খেলায় অংশ নিয়ে ২৩০ রানে পরাজিত হয়েছিল। একই বছর মালয়েশিয়া দল প্রথমবারের মতো সাউদারা কাপে অংশগ্রহণ করে। সিঙ্গাপুরের বিপক্ষে অনুষ্ঠিত ৩-দিনের খেলাটি ড্রয়ে পরিণত হয়। এরপর থেকেই দলটি নিয়মিতভাবে সাংবার্ষিকভিত্তিতে সাউদারা কাপে অংশ নিচ্ছে।
১৯৭৯ সালে অনুষ্ঠিত প্রথম আইসিসি ট্রফিতে মালয়েশিয়া অংশ নেয় ও প্রথম রাউন্ডেই বিদায় নেয়। ১৯৮২ ও ১৯৮৬ সালেও তারা এ ফলাফল অব্যাহত রাখে। ১৯৯০ ও ১৯৯৪ সালে তারা প্লেট প্রতিযোগিতায় পৌঁছে।
১৯৯৫ সালের ফেব্রুয়ারি মাসে সিঙ্গাপুরে অনুষ্ঠিত স্টান নাগাইয়া ট্রফির প্রথম আসরে ৩ খেলার একদিনের সিরিজে অংশ নিয়ে সিঙ্গাপুরের কাছে ২-১ ব্যবধানে পরাজিত হয়। ১৯৯৬ সালে স্টান নাগাইয়া ট্রফি জয় ও সাউদারা কাপে ড্র করার ফলে মালয়েশিয়া এসিসি ট্রফি প্রতিযোগিতার প্রথম আসরে স্বাগতিক দেশের মর্যাদা পায়। কিন্তু প্রথম রাউন্ডে দলটি তৃতীয় স্থান লাভ করেছিল।
কালিদু কুলিবালি
কালিদু কুলিবালি (জন্ম: ২০ জুন ১৯৯১) হলেন সেনেগালের একজন পেশাদার ফুটবলার, যিনি ইতালীয় ক্লাব নাপোলি এবং সেনেগাল জাতীয় দলের হয়ে একজন রক্ষণভাগের খেলোয়াড় হিসেবে খেলেন।
২০১০ সালে, ফরাসি ক্লাব মেসের হয়ে খেলার মাধ্যমে কুলিবালি তার পেশাদার ক্যারিয়ার শুরু করেন। অতঃপর ২০১২ সালে, তিনি বেলজীয় ক্লাব খেঙ্কে যোগদান করেন। ২০১৪ সালে, ইতালীয় ক্লাব নাপোলিতে যোগদান করেন, যেখানে তিনি ইতালির সেরা রক্ষণভাগের খেলোয়াড়ে পরিণত হন।
২০১৮ সালের ১৭শে মে তারিখে, তিনি রাশিয়ায় অনুষ্ঠিত ২০১৮ ফিফা বিশ্বকাপের জন্য ঘোষিত ২৩ সদস্যের সেনেগাল দলে স্থান পান।
ক্লাব
নাপোলি
বিভা দধিচ
বিভা দধিচ কত্থক নৃত্যশৈলীর একজন বিখ্যাত ভারতীয় শাস্ত্রীয় নৃত্যশিল্পী। তিনি প্রথমে রায়গড় কোর্টের নৃত্যশিল্পী পণ্ডিত ফিরতু মহারাজের কাছে এবং পরবর্তীতে পদ্মশ্রী শম্ভু মহারাজের কাছ থেকে গুরু শিষ্য পরম্পরায় কত্থক শিখেছিলেন। তিনি পদ্মশ্রী ড. পুরু দধিচের বরিষ্ঠ শিষ্য এবং স্ত্রী।
বিভা দধিচ ১৯৮৮ সালে খৈরাগড় ইন্দিরা কলা সংগীত বিশ্ববিদ্যালয় থেকে কত্থকে ডক্টরেট পিএইচডি অর্জন করেছেন। তাঁর গবেষণার বিষয় ছিল নৃত্যে হাতের অঙ্গভঙ্গি - ভারতীয় নৃত্য কি বর্ণমালা: হস্ত মুদ্রায়েঁ।
বিভা দধিচকে মধ্য প্রদেশের সর্বোচ্চ বেসমারিক পুরস্কার দ্য শিখর সম্মাননায় ভূষিত করা হয়েছে।
২০১১-১২ সালে তিনি ভারত সরকারের সংস্কৃতি মন্ত্রক থেকে কত্থকে বরিষ্ঠ ফেলোশিপ পেয়েছিলেন।
তিনি একজন প্রতিষ্ঠিত লেখিকা এবং তাঁর গবেষণাকৃত বই ভারতীয় নৃত্য কি বর্ণমালা: হস্ত মুদ্রায়েঁ (ভারতীয় নৃত্যের অঙ্গভঙ্গির অ আ ক খ) হিন্দি ভাষায় প্রকাশ করেছেন (হার্ডকভার - ২০০৩ )। তাঁর বইটি মধ্য প্রদেশের সরকারি ইন্দোর বিশ্ববিদ্যালয়ের স্নাতক স্তরের জন্য নৃত্য পাঠ্যক্রম হিসেবে নির্ধারিত হয়েছে। ।
ড. বিভা দধিচ ৫০ বছরেরও বেশি সময় ধরে কত্থক অনুবর্তন করার জন্য মুম্বই য়ের ২৫ তম গোপী কৃষ্ণ মহোৎসবে লাইফ-টাইম অ্যাচিভমেন্ট অ্যাওয়ার্ড ২০১৫ পেয়েছেন।
বড় আহ্নিক মন্দির, পুঠিয়া
বড় আহ্নিক মন্দির পুঠিয়া মন্দির চত্বরের সর্ব দক্ষিণে অবস্থিত মন্দির। এটি রাজশাহীর পুঠিয়া উপজেলায় অবস্থিত। পুঠিয়ার রাজারা এটি নির্মাণ করেন।
অবস্থান
রাজশাহী জেলা সদর হতে ৩২ কিঃ মিঃ উত্তর-পূর্ব দিকে ঢাকা-রাজশাহী মহাসড়কের পাশেই এর অবস্থান। এর ঠিক উত্তর পাশে ছোট গোবিন্দ মন্দির অবস্থিত।
স্থাপত্যশৈলী
পুর্বমুখী এই মন্দিরে পাশাপাশি তিনটি কক্ষ আছে। মাঝের কক্ষটি তুলনামুলকভাবে বড় এবং পাশের কক্ষ দুইটি বর্গাকৃতির ও সম আয়তনের। এই কক্ষ দুইটিতে একটি করে সরু প্রবেশ পথ আছে। মন্দিরের পুর্ব দিকে তিনটি খিলান দরজা এবং উপরে দৌচালা আকৃতির ছাদ আছে। আয়তাকার এ মন্দিরের উত্তর, দক্ষিণ ও পশ্চিম পাশের দেয়াল সমতল এবং সেখানে কোন অলংকরণ নেই। তবে সাম্নের দিকের দেয়াল পোড়ামাটির চিত্রফলক দ্বারা সজ্জিত।
বানৌজা প্রত্যয়
বাংলাদেশ নৌবাহিনী জাহাজ (সংক্ষেপেঃ বানৌজা) প্রত্যয় বাংলাদেশ নৌবাহিনীর একটি স্বাধীনতা-শ্রেণীর কর্ভেট। যা উচ্যাং শিপইয়ার্ড কর্তৃক নির্মিত হয়। এটি বাংলাদেশ নৌবাহিনীতে যুক্ত হওয়া এই শ্রেণীর দ্বিতীয় জাহাজ যা বহুমাত্রিক যুদ্ধ ক্ষমতা সম্পন্ন। জাহাজটি গভীর সমুদ্রে অবৈধ অনুপ্রবেশ, চোরাচালান রোধ, জলদস্যুতা দমন, সমুদ্রে উদ্ধার অভিযান, সুনীল অর্থনীতির বিভিন্ন কর্মকান্ড পরিচালনাসহ মৎস্য ও প্রাকৃতিক সম্পদ রক্ষায় কার্যকরী ভূমিকা রাখতে সক্ষম।
বৈশিষ্ট্য ও যান্ত্রিক কাঠামো
জাহাজটির দৈর্ঘ্য, প্রস্থ এবং ওজন ১,৪০০ টন। জাহাজটিতে দুইটি জার্মানির তৈরি এসইএমটি পিয়েলসটিক ১২পিএ৬ ডিজেল ইঞ্জিন রয়েছে যার সাহায্যে সে সর্ব্বোচ্চ  গতিবেগে চলতে সক্ষম। জাহাজটিতে সামনে ও পিছনে দুইটি আলাদা শক্তি উৎপাদন কেন্দ্র রয়েছে এবং একটি অকার্যকর হয়ে পড়লেও অন্যটির সাহায্যে জাহাজটি কার্যক্রম চালাতে সক্ষম। চিরাচরিত গোলাকার সম্মুখভাগের পরিবর্তে জাহাজটিকে ভি-আকৃতিতে তৈরি করা হয়েছে যাতে উত্তাল সমূদ্রেও দ্রুতগতিতে চলতে পারে। কিন্তু জাহাজটিতে কোন সোনার না থাকায় এটি খুব সীমিত মাত্রায় ডুবোজাহাজ-বিধ্বংসী কার্যক্রম চালাতে সক্ষম। বানৌজা প্রত্যয়ে একটি হেলিকপ্টার ডেক রয়েছে যেখানে একটি মধ্যম আকৃতির হেলিকপ্টার ওঠানাম করতে পারে তবে এতে কোনো হ্যাঙ্গার নেই।
ইলেক্ট্রনিক্স
জাহাজটি কেলভিন হিউজেস এর তৈরি শার্পআই আই-ব্যান্ড (এক্স-ব্যান্ড)  এবং  শার্পআই ই/এফ-ব্যান্ড (এস-ব্যান্ড) রাডার এবং মান্টাডিজিটাল কৌশলগত প্রদর্শন সফটওয়ার ব্যবহার করে। এই রাডারগুলো সমুদ্রপৃষ্ঠে অনুসন্ধান এবং নৌচালনার কাজে ব্যবহৃত হয়। পাশাপাশি হেলিকপ্টার উড্ডয়ন ও অবতরন নিয়ন্ত্রণের জন্যও এই রাডার ব্যবহার করা যায়।
অস্ত্রসজ্জা
জাহাজটিতে একটি এইচ/পিজে-২৬ ৭৬ মিমি কামান রয়েছে যা জাহাজের সম্মুখভাগে বসানো হয়েছে। সমুদ্রপৃষ্ঠে থাকা হুমকি মোকাবেলা করার জন্য রয়েছে চারটিসি-৮০২এ জাহাজবিধ্বংসী ক্ষেপণাস্ত্র। জাহাজটির নিজস্ব প্রতিরক্ষার জন্য রয়েছে দুইটি  এইচ/পিজে-১৭ ৩০ মিমি দূর-নিয়ন্ত্রিত কামান। আকাশ প্রতিরক্ষার জন্য রয়েছে ৮টি এফএল-৩০০০এন বিমান বিধ্বংসী ক্ষেপণাস্ত্র। জাহাজটিতে দুইটি ৬-টিউব বিশিষ্ট টাইপ ৮৭ ডুবোজাহাজ বিধ্বংসী রকেট লঞ্চারও রয়েছে।
লুডভিগ ভিটগেনস্টাইন
লুডভিগ ভিটগেনস্টাইন (জার্মান: Ludwig Wittgenstein লুট্‌ভ়িক্‌ ভ়িট্‌গেন্‌শ্‌টায়্‌ন্‌, এপ্রিল ২৬, ১৮৮৯ - এপ্রিল ২৯, ১৯৫১) একজন অস্ট্রীয় দার্শনিক, যার মূল অবদান যুক্তি, গণিত, মন ও ভাষার দর্শনে। তার প্রভাব বিশালব্যাপী এবং বিংশ শতাব্দীর সবচেয়ে গুরুত্বপূর্ণ দার্শনিক হিসেবে বিবাচিত হন। ৬২ বছর বয়সে তার মৃত্যুর আগে তার পুস্তক আকারে প্রকাশিত একমাত্র কর্ম ছিল ট্র্যাকট্যাটাস লজিকো ফিলোসফিকাস।
জীবনী
তার জন্ম ভিয়েনাতে, পিতা ও মাতার নাম কার্ল ও লিওপল্ডাইন ভিটগেনস্টাইন। অস্ট্রো-হাঙ্গেরিয়ান সাম্রাজ্যের সবচেয়ে অভিজাত পরিবারগুলির একটিতে জন্ম হয়েছিল তার।
শেষ দিনগুলি
তিনি দুরারোগ্য ব্যাধি ক্যান্সারে আক্রান্ত হয়ে মারা যান। এডয়ার্ড ভন বেভানের বাড়িতে তিনি শেষ নিঃশ্বাস ত্যাগ করেন। তার শেষ বাক্য ছিলঃ "তাদেরকে বলো, আমি এক অসাধারণ জীবন যাপন করেছি"।
সফটওয়্যার পরীক্ষণ
সফটওয়্যার টেস্টিং হলো একটি নিরীক্ষণ বা মূল্যায়ন প্রক্রিয়া যা সফটওয়্যারের সাথে সম্পর্কিত মানুষগুলোকে সফটওয়্যারের মান সম্পর্কে তথ্য প্রদান করে। সফটওয়্যার টেস্টিং এর সাহায্যে সফটওয়্যারের ত্রুটি খুঁজে বের করাসহ, সফটওয়্যারটি বাস্তবায়ন ও ব্যবহারের ক্ষেত্রে সম্ভাব্য ঝুঁকিসমুহ সম্পর্কে আগাম ধারণা পাওয়া যায়। সফটওয়্যার টেস্ট বা নিরীক্ষণ প্রক্রিয়ার মধ্যে থাকে মূলত একটি প্রোগ্রাম বা অ্যাপ্লিকেশন নির্বাহের মাধ্যমে সেই প্রোগ্রাম বা অ্যাপ্লিকেশনের ত্রুটিসমূহ খুঁজে বের করা এবং এটা নিশ্চিত করা যে, তৈরিকৃত সফটওয়্যারটি ব্যবহার উপযোগী।
সফটওয়্যার টেস্টিং বা সফটওয়্যার নিরীক্ষণের ক্ষেত্রে সম্পূর্ণ সফটওয়্যার বা সফটওয়্যারের অংশবিশেষ নির্বাহের মাধ্যমে খুঁজে দেখা হয় যে, সফটওয়্যারের বিভিন্ন অংশ সুনির্দিষ্ট কিছু বৈশিষ্ট্য প্রদর্শন করছে কিনা। সফটওয়্যারের যে অংশটি পরীক্ষা-নিরীক্ষা করা হচ্ছে, সেটিঃ
সফটওয়্যার নিরীক্ষণের সময় মূলত উপরের বিষয়সমূহ নিরীক্ষণ করা হয়ে থাকে। <!-- As the number of possible tests for even simple software components is practically infinite, all software testing uses some strategy to select tests that are feasible for the available time and resources. As a result, software testing typically (but not exclusively) attempts to execute a program or application with the intent of finding software bugs (errors or other defects). The job of testing is an iterative process as when one bug is fixed, it can illuminate other, deeper bugs, or can even create new ones.
Software testing can provide objective, independent information about the quality of software and risk of its failure to users or sponsors.
Software testing can be conducted as soon as executable software (even if partially complete) exists. The overall approach to software development often determines when and how testing is conducted. For example, in a phased process, most testing occurs after system requirements have been defined and then implemented in testable programs. In contrast, under an agile approach, requirements, programming, and testing are often done concurrently.
Overview
Although testing can determine the correctness of software under the assumption of some specific hypotheses (see the hierarchy of testing difficulty below), testing cannot identify all the defects within the software. Instead, it furnishes a criticism or comparison that compares the state and behavior of the product against test oracles—principles or mechanisms by which someone might recognize a problem. These oracles may include (but are not limited to) specifications, contracts, comparable products, past versions of the same product, inferences about intended or expected purpose, user or customer expectations, relevant standards, applicable laws, or other criteria.
A primary purpose of testing is to detect software failures so that defects may be discovered and corrected. Testing cannot establish that a product functions properly under all conditions, but only that it does not function properly under specific conditions. The scope of software testing often includes the examination of code as well as the execution of that code in various environments and conditions as well as examining the aspects of code: does it do what it is supposed to do and do what it needs to do. In the current culture of software development, a testing organization may be separate from the development team. There are various roles for testing team members. Information derived from software testing may be used to correct the process by which software is developed.
Every software product has a target audience. For example, the audience for video game software is completely different from banking software. Therefore, when an organization develops or otherwise invests in a software product, it can assess whether the software product will be acceptable to its end users, its target audience, its purchasers and other stakeholders. Software testing aids the process of attempting to make this assessment.
Defects and failures
Not all software defects are caused by coding errors. One common source of expensive defects is requirement gaps, i.e., unrecognized requirements that result in errors of omission by the program designer. Requirement gaps can often be non-functional requirements such as testability, scalability, maintainability, performance, and security.
Software faults occur through the following processes. A programmer makes an error (mistake), which results in a defect (fault, bug) in the software source code. If this defect is executed, in certain situations the system will produce wrong results, causing a failure. Not all defects will necessarily result in failures. For example, defects in the dead code will never result in failures. A defect can turn into a failure when the environment is changed. Examples of these changes in environment include the software being run on a new computer hardware platform, alterations in source data, or interacting with different software. A single defect may result in a wide range of failure symptoms.
Input combinations and preconditions
A fundamental problem with software testing is that testing under all combinations of inputs and preconditions (initial state) is not feasible, even with a simple product. This means that the number of defects in a software product can be very large and defects that occur infrequently are difficult to find in testing. More significantly, non-functional dimensions of quality (how it is supposed to be versus what it is supposed to do)—usability, scalability, performance, compatibility, reliability—can be highly subjective; something that constitutes sufficient value to one person may be intolerable to another.
Software developers can't test everything, but they can use combinatorial test design to identify the minimum number of tests needed to get the coverage they want. Combinatorial test design enables users to get greater test coverage with fewer tests. Whether they are looking for speed or test depth, they can use combinatorial test design methods to build structured variation into their test cases.
Economics
A study conducted by NIST in 2002 reports that software bugs cost the U.S. economy $59.5 billion annually. More than a third of this cost could be avoided, if better software testing was performed.
Outsourcing software testing because of costs is very common, with China, the Philippines and India being preferred destinations.
Roles
Software testing can be done by dedicated software testers. Until the 1980s, the term "software tester" was used generally, but later it was also seen as a separate profession. Regarding the periods and the different goals in software testing, different roles have been established, such as test manager, test lead, test analyst, test designer, tester, automation developer, and test administrator. Software testing can also be performed by non-dedicated software testers.
Static, dynamic and passive testing
There are many approaches available in software testing. Reviews, walkthroughs, or inspections are referred to as static testing, whereas executing programmed code with a given set of test cases is referred to as dynamic testing.
Static testing is often implicit, like proofreading, plus when programming tools/text editors check source code structure or compilers (pre-compilers) check syntax and data flow as static program analysis. Dynamic testing takes place when the program itself is run. Dynamic testing may begin before the program is 100% complete in order to test particular sections of code and are applied to discrete functions or modules. Typical techniques for these are either using stubs/drivers or execution from a debugger environment.
Static testing involves verification, whereas dynamic testing also involves validation.
Passive testing means verifying the system behavior without any interaction with the software product. Contrary to active testing, testers do not provide any test data but look at system logs and traces. They mine for patterns and specific behavior in order to make some kind of decisions. This is related to offline runtime verification and log analysis.
The "box" approach
Software testing methods are traditionally divided into white- and black-box testing. These two approaches are used to describe the point of view that the tester takes when designing test cases. A hybrid approach called grey-box testing may also be applied to software testing methodology. With the concept of grey-box testing—which develops tests from specific design elements—gaining prominence, this "arbitrary distinction" between black- and white-box testing has faded somewhat.
White-box testing
While white-box testing can be applied at the unit, integration, and system levels of the software testing process, it is usually done at the unit level. It can test paths within a unit, paths between units during integration, and between subsystems during a system–level test. Though this method of test design can uncover many errors or problems, it might not detect unimplemented parts of the specification or missing requirements.
Techniques used in white-box testing include:
Code coverage tools can evaluate the completeness of a test suite that was created with any method, including black-box testing. This allows the software team to examine parts of a system that are rarely tested and ensures that the most important function points have been tested. Code coverage as a software metric can be reported as a percentage for:
100% statement coverage ensures that all code paths or branches (in terms of control flow) are executed at least once. This is helpful in ensuring correct functionality, but not sufficient since the same code may process different inputs correctly or incorrectly. Pseudo-tested functions and methods are those that are covered but not specified (it is possible to remove their body without breaking any test case).
Black-box testing
থাম্ব|200px|Black box diagram Black-box testing (also known as functional testing) treats the software as a "black box," examining functionality without any knowledge of internal implementation, without seeing the source code. The testers are only aware of what the software is supposed to do, not how it does it. Black-box testing methods include: equivalence partitioning, boundary value analysis, all-pairs testing, state transition tables, decision table testing, fuzz testing, model-based testing, use case testing, exploratory testing, and specification-based testing.
Specification-based testing may be necessary to assure correct functionality, but it is insufficient to guard against complex or high-risk situations.
One advantage of the black box technique is that no programming knowledge is required. Whatever biases the programmers may have had, the tester likely has a different set and may emphasize different areas of functionality. On the other hand, black-box testing has been said to be "like a walk in a dark labyrinth without a flashlight." Because they do not examine the source code, there are situations when a tester writes many test cases to check something that could have been tested by only one test case or leaves some parts of the program untested.
This method of test can be applied to all levels of software testing: unit, integration, system and acceptance. It typically comprises most if not all testing at higher levels, but can also dominate unit testing as well.
Component interface testing is a variation of black-box testing, with the focus on the data values beyond just the related actions of a subsystem component. The practice of component interface testing can be used to check the handling of data passed between various units, or subsystem components, beyond full integration testing between those units. The data being passed can be considered as "message packets" and the range or data types can be checked, for data generated from one unit, and tested for validity before being passed into another unit. One option for interface testing is to keep a separate log file of data items being passed, often with a timestamp logged to allow analysis of thousands of cases of data passed between units for days or weeks. Tests can include checking the handling of some extreme data values while other interface variables are passed as normal values. Unusual data values in an interface can help explain unexpected performance in the next unit.
Visual testing
The aim of visual testing is to provide developers with the ability to examine what was happening at the point of software failure by presenting the data in such a way that the developer can easily find the information she or he requires, and the information is expressed clearly.
At the core of visual testing is the idea that showing someone a problem (or a test failure), rather than just describing it, greatly increases clarity and understanding. Visual testing, therefore, requires the recording of the entire test process – capturing everything that occurs on the test system in video format. Output videos are supplemented by real-time tester input via picture-in-a-picture webcam and audio commentary from microphones.
Visual testing provides a number of advantages. The quality of communication is increased drastically because testers can show the problem (and the events leading up to it) to the developer as opposed to just describing it and the need to replicate test failures will cease to exist in many cases. The developer will have all the evidence she or he requires of a test failure and can instead focus on the cause of the fault and how it should be fixed.
Ad hoc testing and exploratory testing are important methodologies for checking software integrity, because they require less preparation time to implement, while the important bugs can be found quickly. In ad hoc testing, where testing takes place in an improvised, impromptu way, the ability of the tester(s) to base testing off documented methods and then improvise variations of those tests can result in more rigorous examination of defect fixes. However, unless strict documentation of the procedures are maintained, one of the limits of ad hoc testing is lack of repeatability.
Grey-box testing
Grey-box testing (American spelling: gray-box testing) involves having knowledge of internal data structures and algorithms for purposes of designing tests while executing those tests at the user, or black-box level. The tester will often have access to both "the source code and the executable binary." Grey-box testing may also include reverse engineering (using dynamic code analysis) to determine, for instance, boundary values or error messages. Manipulating input data and formatting output do not qualify as grey-box, as the input and output are clearly outside of the "black box" that we are calling the system under test. This distinction is particularly important when conducting integration testing between two modules of code written by two different developers, where only the interfaces are exposed for the test.
By knowing the underlying concepts of how the software works, the tester makes better-informed testing choices while testing the software from outside. Typically, a grey-box tester will be permitted to set up an isolated testing environment with activities such as seeding a database. The tester can observe the state of the product being tested after performing certain actions such as executing SQL statements against the database and then executing queries to ensure that the expected changes have been reflected. Grey-box testing implements intelligent test scenarios, based on limited information. This will particularly apply to data type handling, exception handling, and so on.
Testing levels
Broadly speaking, there are at least three levels of testing: unit testing, integration testing, and system testing. However, a fourth level, acceptance testing, may be included by developers. This may be in the form of operational acceptance testing or be simple end-user (beta) testing, testing to ensure the software meets functional expectations. Tests are frequently grouped into one of these levels by where they are added in the software development process, or by the level of specificity of the test.
Unit testing
Unit testing refers to tests that verify the functionality of a specific section of code, usually at the function level. In an object-oriented environment, this is usually at the class level, and the minimal unit tests include the constructors and destructors.
These types of tests are usually written by developers as they work on code (white-box style), to ensure that the specific function is working as expected. One function might have multiple tests, to catch corner cases or other branches in the code. Unit testing alone cannot verify the functionality of a piece of software, but rather is used to ensure that the building blocks of the software work independently from each other.
Unit testing is a software development process that involves a synchronized application of a broad spectrum of defect prevention and detection strategies in order to reduce software development risks, time, and costs. It is performed by the software developer or engineer during the construction phase of the software development life cycle. Unit testing aims to eliminate construction errors before code is promoted to additional testing; this strategy is intended to increase the quality of the resulting software as well as the efficiency of the overall development process.
Depending on the organization's expectations for software development, unit testing might include static code analysis, data-flow analysis, metrics analysis, peer code reviews, code coverage analysis and other software testing practices.
Integration testing
Integration testing is any type of software testing that seeks to verify the interfaces between components against a software design. Software components may be integrated in an iterative way or all together ("big bang"). Normally the former is considered a better practice since it allows interface issues to be located more quickly and fixed.
Integration testing works to expose defects in the interfaces and interaction between integrated components (modules). Progressively larger groups of tested software components corresponding to elements of the architectural design are integrated and tested until the software works as a system.
Integration tests usually involves a lot of code, and produce traces that are larger than those produced by unit tests. This has an impact on the ease of localizing the fault when an integration test fails. To overcome this issue, it has been proposed to automatically cut the large tests in smaller pieces to improve fault localization.
System testing
System testing tests a completely integrated system to verify that the system meets its requirements. For example, a system test might involve testing a logon interface, then creating and editing an entry, plus sending or printing results, followed by summary processing or deletion (or archiving) of entries, then logoff.
Operational acceptance testing
Operational acceptance is used to conduct operational readiness (pre-release) of a product, service or system as part of a quality management system. OAT is a common type of non-functional software testing, used mainly in software development and software maintenance projects. This type of testing focuses on the operational readiness of the system to be supported, or to become part of the production environment. Hence, it is also known as operational readiness testing (ORT) or Operations readiness and assurance (OR&A) testing. Functional testing within OAT is limited to those tests that are required to verify the non-functional aspects of the system.
In addition, the software testing should ensure that the portability of the system, as well as working as expected, does not also damage or partially corrupt its operating environment or cause other processes within that environment to become inoperative.
Testing types, techniques and tactics
Different labels and ways of grouping testing may be testing types, software testing tactics or techniques. থাম্ব|TestingCup - Polish Championship in Software Testing, [[Katowice, May 2016]]
Installation testing
Most software systems have installation procedures that are needed before they can be used for their main purpose. Testing these procedures to achieve an installed software system that may be used is known as installation testing.
Compatibility testing
A common cause of software failure (real or perceived) is a lack of its compatibility with other application software, operating systems (or operating system versions, old or new), or target environments that differ greatly from the original (such as a terminal or GUI application intended to be run on the desktop now being required to become a Web application, which must render in a Web browser). For example, in the case of a lack of backward compatibility, this can occur because the programmers develop and test software only on the latest version of the target environment, which not all users may be running. This results in the unintended consequence that the latest work may not function on earlier versions of the target environment, or on older hardware that earlier versions of the target environment were capable of using. Sometimes such issues can be fixed by proactively abstracting operating system functionality into a separate program module or library.
Smoke and sanity testing
Sanity testing determines whether it is reasonable to proceed with further testing.
Smoke testing consists of minimal attempts to operate the software, designed to determine whether there are any basic problems that will prevent it from working at all. Such tests can be used as build verification test.
Regression testing
Regression testing focuses on finding defects after a major code change has occurred. Specifically, it seeks to uncover software regressions, as degraded or lost features, including old bugs that have come back. Such regressions occur whenever software functionality that was previously working correctly, stops working as intended. Typically, regressions occur as an unintended consequence of program changes, when the newly developed part of the software collides with the previously existing code. Regression testing is typically the largest test effort in commercial software development, due to checking numerous details in prior software features, and even new software can be developed while using some old test cases to test parts of the new design to ensure prior functionality is still supported.
Common methods of regression testing include re-running previous sets of test cases and checking whether previously fixed faults have re-emerged. The depth of testing depends on the phase in the release process and the risk of the added features. They can either be complete, for changes added late in the release or deemed to be risky, or be very shallow, consisting of positive tests on each feature, if the changes are early in the release or deemed to be of low risk. In regression testing, it is important to have strong assertions on the existing behavior. For this, it is possible to generate and add new assertions in existing test cases, this is known as automatic test improvement.
Acceptance testing
Acceptance testing can mean one of two things:
Alpha testing
Alpha testing is simulated or actual operational testing by potential users/customers or an independent test team at the developers' site. Alpha testing is often employed for off-the-shelf software as a form of internal acceptance testing before the software goes to beta testing.
Beta testing
Beta testing comes after alpha testing and can be considered a form of external user acceptance testing. Versions of the software, known as beta versions, are released to a limited audience outside of the programming team known as beta testers. The software is released to groups of people so that further testing can ensure the product has few faults or bugs. Beta versions can be made available to the open public to increase the feedback field to a maximal number of future users and to deliver value earlier, for an extended or even indefinite period of time (perpetual beta).
Functional vs non-functional testing
Functional testing refers to activities that verify a specific action or function of the code. These are usually found in the code requirements documentation, although some development methodologies work from use cases or user stories. Functional tests tend to answer the question of "can the user do this" or "does this particular feature work."
Continuous testing
Continuous testing is the process of executing automated tests as part of the software delivery pipeline to obtain immediate feedback on the business risks associated with a software release candidate. Continuous testing includes the validation of both functional requirements and non-functional requirements; the scope of testing extends from validating bottom-up requirements or user stories to assessing the system requirements associated with overarching business goals.
Destructive testing
Destructive testing attempts to cause the software or a sub-system to fail. It verifies that the software functions properly even when it receives invalid or unexpected inputs, thereby establishing the robustness of input validation and error-management routines. Software fault injection, in the form of fuzzing, is an example of failure testing. Various commercial non-functional testing tools are linked from the software fault injection page; there are also numerous open-source and free software tools available that perform destructive testing.
Software performance testing
Performance testing is generally executed to determine how a system or sub-system performs in terms of responsiveness and stability under a particular workload. It can also serve to investigate, measure, validate or verify other quality attributes of the system, such as scalability, reliability and resource usage.
Load testing is primarily concerned with testing that the system can continue to operate under a specific load, whether that be large quantities of data or a large number of users. This is generally referred to as software scalability. The related load testing activity of when performed as a non-functional activity is often referred to as endurance testing. Volume testing is a way to test software functions even when certain components (for example a file or database) increase radically in size. Stress testing is a way to test reliability under unexpected or rare workloads. Stability testing (often referred to as load or endurance testing) checks to see if the software can continuously function well in or above an acceptable period.
There is little agreement on what the specific goals of performance testing are. The terms load testing, performance testing, scalability testing, and volume testing, are often used interchangeably.
Real-time software systems have strict timing constraints. To test if timing constraints are met, real-time testing is used.
Usability testing
Usability testing is to check if the user interface is easy to use and understand. It is concerned mainly with the use of the application. This is not a kind of testing that can be automated; actual human users are needed, being monitored by skilled UI designers.
Accessibility testing
Accessibility testing may include compliance with standards such as:
Security testing
Security testing is essential for software that processes confidential data to prevent system intrusion by hackers.
The International Organization for Standardization (ISO) defines this as a "type of testing conducted to evaluate the degree to which a test item, and associated data and information, are protected so that unauthorised persons or systems cannot use, read or modify them, and authorized persons or systems are not denied access to them."
Internationalization and localization
Testing for internationalization and localization validates that the software can be used with different languages and geographic regions. The process of pseudolocalization is used to test the ability of an application to be translated to another language, and make it easier to identify when the localization process may introduce new bugs into the product.
Globalization testing verifies that the software is adapted for a new culture (such as different currencies or time zones).
Actual translation to human languages must be tested, too. Possible localization and globalization failures include:
Development testing
Depending on the organization's expectations for software development, Development Testing might include static code analysis, data flow analysis, metrics analysis, peer code reviews, unit testing, code coverage analysis, traceability, and other software testing practices.
A/B testing
A/B testing is a method of running a controlled experiment to determine if a proposed change is more effective than the current approach. Customers are routed to either a current version (control) of a feature, or to a modified version (treatment) and data is collected to determine which version is better at achieving the desired outcome.
Concurrent testing
Concurrent or concurrency testing assesses the behaviour and performance of software and systems that use concurrent computing, generally under normal usage conditions. Typical problems this type of testing will expose are deadlocks, race conditions and problems with shared memory/resource handling.
Output comparison testing
Creating a display expected output, whether as data comparison of text or screenshots of the UI, is sometimes called snapshot testing or Golden Master Testing unlike many other forms of testing, this cannot detect failures automatically and instead requires that a human evaluate the output for inconsistencies.
Traditional waterfall development model
A common practice in waterfall development is that testing is performed by an independent group of testers. This can happen:
However, even in the waterfall development model, unit testing is often done by the software development team even when further testing is done by a separate team.
Agile or XP development model
In contrast, some emerging software disciplines such as extreme programming and the agile software development movement, adhere to a "test-driven software development" model. In this process, unit tests are written first, by the software engineers (often with pair programming in the extreme programming methodology). The tests are expected to fail initially. Each failing test is followed by writing just enough code to make it pass. This means the test suites are continuously updated as new failure conditions and corner cases are discovered, and they are integrated with any regression tests that are developed. Unit tests are maintained along with the rest of the software source code and generally integrated into the build process (with inherently interactive tests being relegated to a partially manual build acceptance process).
The ultimate goals of this test process are to support continuous integration and to reduce defect rates.
This methodology increases the testing effort done by development, before reaching any formal testing team. In some other development models, most of the test execution occurs after the requirements have been defined and the coding process has been completed.
A sample testing cycle
Although variations exist between organizations, there is a typical cycle for testing. The sample below is common among organizations employing the Waterfall development model. The same practices are commonly found in other development models, but might not be as clear or explicit.
Automated testing
While automation cannot reproduce everything that a human can do (and all the ways they think of doing it), it can be very useful for regression testing. However, it does require a well-developed test suite of testing scripts in order to be truly useful.
Testing tools
Program testing and fault detection can be aided significantly by testing tools and debuggers. Testing/debug tools include features such as:
Some of these features may be incorporated into a single composite tool or an Integrated Development Environment (IDE).
Measurement in software testing
Quality measures include such topics as correctness, completeness, security and ISO/IEC 9126 requirements such as capability, reliability, efficiency, portability, maintainability, compatibility, and usability.
There are a number of frequently used software metrics, or measures, which are used to assist in determining the state of the software or the adequacy of the testing.
Hierarchy of testing difficulty
Based on the amount of test cases required to construct a complete test suite in each context (i.e. a test suite such that, if it is applied to the implementation under test, then we collect enough information to precisely determine whether the system is correct or incorrect according to some specification), a hierarchy of testing difficulty has been proposed. It includes the following testability classes:
It has been proved that each class is strictly included in the next. For instance, testing when we assume that the behavior of the implementation under test can be denoted by a deterministic finite-state machine for some known finite sets of inputs and outputs and with some known number of states belongs to Class I (and all subsequent classes). However, if the number of states is not known, then it only belongs to all classes from Class II on. If the implementation under test must be a deterministic finite-state machine failing the specification for a single trace (and its continuations), and its number of states is unknown, then it only belongs to classes from Class III on. Testing temporal machines where transitions are triggered if inputs are produced within some real-bounded interval only belongs to classes from Class IV on, whereas testing many non-deterministic systems only belongs to Class V (but not all, and some even belong to Class I). The inclusion into Class I does not require the simplicity of the assumed computation model, as some testing cases involving implementations written in any programming language, and testing implementations defined as machines depending on continuous magnitudes, have been proved to be in Class I. Other elaborated cases, such as the testing framework by Matthew Hennessy under must semantics, and temporal machines with rational timeouts, belong to Class II.
Testing artifacts
A software testing process can produce several artifacts. The actual artifacts produced are a factor of the software development model used, stakeholder and organisational needs.
Certifications
Several certification programs exist to support the professional aspirations of software testers and quality assurance specialists. Note that a few practitioners argue that the testing field is not ready for certification, as mentioned in the Controversy section.
Controversy
Some of the major software testing controversies include:
The data from which this table is extrapolated is scant. Laurent Bossavit says in his analysis: The "smaller projects" curve turns out to be from only two teams of first-year students, a sample size so small that extrapolating to "smaller projects in general" is totally indefensible. The GTE study does not explain its data, other than to say it came from two projects, one large and one small. The paper cited for the Bell Labs "Safeguard" project specifically disclaims having collected the fine-grained data that Boehm's data points suggest. The IBM study (Fagan's paper) contains claims that seem to contradict Boehm's graph and no numerical results that clearly correspond to his data points.
Software verification and validation
Software testing is used in association with verification and validation:
The terms verification and validation are commonly used interchangeably in the industry; it is also common to see these two terms defined with contradictory definitions. According to the IEEE Standard Glossary of Software Engineering Terminology:
And, according to the ISO 9000 standard:
The contradiction is caused by the use of the concepts of requirements and specified requirements but with different meanings.
In the case of IEEE standards, the specified requirements, mentioned in the definition of validation, are the set of problems, needs and wants of the stakeholders that the software must solve and satisfy. Such requirements are documented in a Software Requirements Specification (SRS). And, the products mentioned in the definition of verification, are the output artifacts of every phase of the software development process. These products are, in fact, specifications such as Architectural Design Specification, Detailed Design Specification, etc. The SRS is also a specification, but it cannot be verified (at least not in the sense used here, more on this subject below).
But, for the ISO 9000, the specified requirements are the set of specifications, as just mentioned above, that must be verified. A specification, as previously explained, is the product of a software development process phase that receives another specification as input. A specification is verified successfully when it correctly implements its input specification. All the specifications can be verified except the SRS because it is the first one (it can be validated, though). Examples: The Design Specification must implement the SRS; and, the Construction phase artifacts must implement the Design Specification.