rajpurkar/squad huggingface dataset:
Title: Software_testing

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). Of course these tests fail initially; as they are expected to. Then as code is written it passes incrementally larger portions of the test suites. 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 goal of this test process is to achieve continuous integration where software updates can be published to the public frequently.

Question: Which two current movements adhere to the "test-driven software development"?
Answer: extreme programming and the agile software development

Question: Under the development of agile software and extreme programing what is written first?
Answer: unit tests are written first

Question: What is the goal of Unit testing?
Answer: achieve continuous integration where software updates can be published to the public frequently
Title: Software_testing

Bottom Up Testing is an approach to integrated testing where the lowest level components (modules, procedures, and functions) are tested first, then integrated and used to facilitate the testing of higher level components. After the integration testing of lower level integrated modules, the next level of modules will be formed and can be used for integration testing. The process is repeated until the components at the top of the hierarchy are tested. This approach is helpful only when all or most of the modules of the same development level are ready.[citation needed] This method also helps to determine the levels of software developed and makes it easier to report testing progress in the form of a percentage.[citation needed]

Question: What three components make up Bottom Up Testing?
Answer: modules, procedures, and functions

Question: Bottom Up Testing helps facilitate the testing of what?
Answer: the testing of higher level components

Question: What does Bottom Up Testing also help with once the process has been repeated over and over again at all levels?
Answer: makes it easier to report testing progress in the form of a percentage
Title: Software_testing

It has been proved that each class is strictly included into 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.

Question: If the number of states is unknown, what group does this fall into?
Answer: Class II

Question: There are three classes, what has been concluded and proven for all classes?
Answer: each class is strictly included into the next

Question: If the number of states are unknown and the finite state of the machine is failing for a single trace, which group does this fall into?
Answer: Class III
Title: Software_testing

Several certification programs exist to support the professional aspirations of software testers and quality assurance specialists. No certification now offered actually requires the applicant to show their ability to test software. No certification is based on a widely accepted body of knowledge. This has led some to declare that the testing field is not ready for certification. Certification itself cannot measure an individual's productivity, their skill, or practical knowledge, and cannot guarantee their competence, or professionalism as a tester.

Question: With several certifications out there that can be aquired, what is the one trait they all share?
Answer: requires the applicant to show their ability to test software

Question: What has the inability for the applicant to show how well they test led to?
Answer: testing field is not ready for certification

Question: What four traits can a certification not measure?
Answer: individual's productivity, their skill, or practical knowledge
Title: Software_testing

Software testing is a part of the software quality assurance (SQA) process.:347 In SQA, software process specialists and auditors are concerned for the software development process rather than just the artifacts such as documentation, code and systems. They examine and change the software engineering process itself to reduce the number of faults that end up in the delivered software: the so-called "defect rate". What constitutes an "acceptable defect rate" depends on the nature of the software; A flight simulator video game would have much higher defect tolerance than software for an actual airplane. Although there are close links with SQA, testing departments often exist independently, and there may be no SQA function in some companies.[citation needed]

Question: What makes up part of the SQA?
Answer: Software testing

Question: What is the primary concern for the software specialist and auditors?
Answer: software development process

Question: What type of software would have a better defect tolerance?
Answer: video game
Title: Glass

Many applications of silicate glasses derive from their optical transparency, which gives rise to one of silicate glasses' primary uses as window panes. Glass will transmit, reflect and refract light; these qualities can be enhanced by cutting and polishing to make optical lenses, prisms, fine glassware, and optical fibers for high speed data transmission by light. Glass can be colored by adding metallic salts, and can also be painted and printed with vitreous enamels. These qualities have led to the extensive use of glass in the manufacture of art objects and in particular, stained glass windows. Although brittle, silicate glass is extremely durable, and many examples of glass fragments exist from early glass-making cultures. Because glass can be formed or molded into any shape, and also because it is a sterile product, it has been traditionally used for vessels: bowls, vases, bottles, jars and drinking glasses. In its most solid forms it has also been used for paperweights, marbles, and beads. When extruded as glass fiber and matted as glass wool in a way to trap air, it becomes a thermal insulating material, and when these glass fibers are embedded into an organic polymer plastic, they are a key structural reinforcement part of the composite material fiberglass. Some objects historically were so commonly made of silicate glass that they are simply called by the name of the material, such as drinking glasses and reading glasses.

Question: What ingredient makes glass colorful?
Answer: metallic salts

Question: What in combination with glass fibers is used to make fiberglass?
Answer: organic polymer plastic

Question: What quality of silicate glass allows it to be used for windows?
Answer: transparency

Question: What type of glass products can be used for sending information?
Answer: optical fibers

Question: In what product are glass fibers used to hold dead air?
Answer: thermal insulating material
Title: Glass

Most common glass contains other ingredients to change its properties. Lead glass or flint glass is more 'brilliant' because the increased refractive index causes noticeably more specular reflection and increased optical dispersion. Adding barium also increases the refractive index. Thorium oxide gives glass a high refractive index and low dispersion and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eyeglasses.[citation needed] Iron can be incorporated into glass to absorb infrared energy, for example in heat absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs UV wavelengths.

Question: What element is used in glass to keep it from becoming too hot?
Answer: Iron

Question: How does barium affect glass?
Answer: increases the refractive index

Question: What property of thorium oxide has caused it to no longer be used in eyeglasses?
Answer: radioactivity

Question: What is another name for lead glass?
Answer: flint glass

Question: What is the benefit of thorium oxide in addition to its refractive index?
Answer: low dispersion
Title: Glass

Fused quartz is a glass made from chemically-pure SiO2 (silica). It has excellent thermal shock characteristics, being able to survive immersion in water while red hot. However, its high melting-temperature (1723 °C) and viscosity make it difficult to work with. Normally, other substances are added to simplify processing. One is sodium carbonate (Na2CO3, "soda"), which lowers the glass transition temperature. The soda makes the glass water-soluble, which is usually undesirable, so lime (calcium oxide [CaO], generally obtained from limestone), some magnesium oxide (MgO) and aluminium oxide (Al2O3) are added to provide for a better chemical durability. The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass. Soda-lime glasses account for about 90% of manufactured glass.

Question: What causes glass to dissolve in water?
Answer: soda

Question: Why is lime often added to glass?
Answer: better chemical durability

Question: What percentage of soda-lime glass is silica?
Answer: 70 to 74

Question: What is a benefit of fused quartz?
Answer: excellent thermal shock characteristics

Question: What besides viscosity is a drawback of fused quartz?
Answer: high melting-temperature
Title: Glass

Following the glass batch preparation and mixing, the raw materials are transported to the furnace. Soda-lime glass for mass production is melted in gas fired units. Smaller scale furnaces for specialty glasses include electric melters, pot furnaces, and day tanks. After melting, homogenization and refining (removal of bubbles), the glass is formed. Flat glass for windows and similar applications is formed by the float glass process, developed between 1953 and 1957 by Sir Alastair Pilkington and Kenneth Bickerstaff of the UK's Pilkington Brothers, who created a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under the influence of gravity. The top surface of the glass is subjected to nitrogen under pressure to obtain a polished finish. Container glass for common bottles and jars is formed by blowing and pressing methods. This glass is often slightly modified chemically (with more alumina and calcium oxide) for greater water resistance. Further glass forming techniques are summarized in the table Glass forming techniques.

Question: What happens during refining?
Answer: removal of bubbles

Question: What method is used for making windows?
Answer: float glass process

Question: What is used on the surface of window glass to make it smooth?
Answer: nitrogen

Question: What is added to the glass of jars to improve water resistance?
Answer: alumina and calcium oxide

Question: Who were the inventors of the float glass process?
Answer: Alastair Pilkington and Kenneth Bickerstaff
Title: Glass

Glass has the ability to refract, reflect, and transmit light following geometrical optics, without scattering it. It is used in the manufacture of lenses and windows. Common glass has a refraction index around 1.5. This may be modified by adding low-density materials such as boron, which lowers the index of refraction (see crown glass), or increased (to as much as 1.8) with high-density materials such as (classically) lead oxide (see flint glass and lead glass), or in modern uses, less toxic oxides of zirconium, titanium, or barium. These high-index glasses (inaccurately known as "crystal" when used in glass vessels) cause more chromatic dispersion of light, and are prized for their diamond-like optical properties.

Question: What can be used to make glass less refractive?
Answer: boron

Question: What is the refraction index of typical glass?
Answer: 1.5

Question: What is a toxic additive that increases refraction?
Answer: lead oxide

Question: What are high-index glasses erroneously called?
Answer: crystal

Question: Why are high-index glasses valued?
Answer: for their diamond-like optical properties
Title: Glass

The most familiar, and historically the oldest, types of glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. The term glass, in popular usage, is often used to refer only to this type of material, which is familiar from use as window glass and in glass bottles. Of the many silica-based glasses that exist, ordinary glazing and container glass is formed from a specific type called soda-lime glass, composed of approximately 75% silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide, also called lime (CaO), and several minor additives. A very clear and durable quartz glass can be made from pure silica, but the high melting point and very narrow glass transition of quartz make glassblowing and hot working difficult. In glasses like soda lime, the compounds added to quartz are used to lower the melting temperature and improve workability, at a cost in the toughness, thermal stability, and optical transmittance.

Question: Which kinds of glass existed the furthest in the past?
Answer: silicate glasses

Question: What kind of glass are containers made from?
Answer: soda-lime glass

Question: What is sand mostly made of?
Answer: silica

Question: What can a very strong and transparent glass be made from?
Answer: pure silica

Question: What types of glass is the word commonly used to mean?
Answer: silicate glasses
Title: Glass

Glass is in widespread use largely due to the production of glass compositions that are transparent to visible light. In contrast, polycrystalline materials do not generally transmit visible light. The individual crystallites may be transparent, but their facets (grain boundaries) reflect or scatter light resulting in diffuse reflection. Glass does not contain the internal subdivisions associated with grain boundaries in polycrystals and hence does not scatter light in the same manner as a polycrystalline material. The surface of a glass is often smooth since during glass formation the molecules of the supercooled liquid are not forced to dispose in rigid crystal geometries and can follow surface tension, which imposes a microscopically smooth surface. These properties, which give glass its clearness, can be retained even if glass is partially light-absorbing—i.e., colored.

Question: What does glass lack, allowing it to be transparent?
Answer: internal subdivisions

Question: What force gives glass its surface texture?
Answer: surface tension

Question: What, in contrast to glass, doesn't let light pass through?
Answer: polycrystalline materials

Question: What type of glass absorbs some light?
Answer: colored
Title: Glass

Naturally occurring glass, especially the volcanic glass obsidian, has been used by many Stone Age societies across the globe for the production of sharp cutting tools and, due to its limited source areas, was extensively traded. But in general, archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or ancient Egypt. The earliest known glass objects, of the mid third millennium BCE, were beads, perhaps initially created as accidental by-products of metal-working (slags) or during the production of faience, a pre-glass vitreous material made by a process similar to glazing.

Question: What kind of glass exists in nature?
Answer: obsidian

Question: Obsidian is what type of glass?
Answer: volcanic

Question: What was obsidian used to make in prehistoric times?
Answer: cutting tools

Question: When are the oldest beads thought to have been made?
Answer: mid third millennium BCE

Question: What glass-like material is made with a method related to glazing?
Answer: faience
Title: Glass

Color in glass may be obtained by addition of electrically charged ions (or color centers) that are homogeneously distributed, and by precipitation of finely dispersed particles (such as in photochromic glasses). Ordinary soda-lime glass appears colorless to the naked eye when it is thin, although iron(II) oxide (FeO) impurities of up to 0.1 wt% produce a green tint, which can be viewed in thick pieces or with the aid of scientific instruments. Further FeO and Cr2O3 additions may be used for the production of green bottles. Sulfur, together with carbon and iron salts, is used to form iron polysulfides and produce amber glass ranging from yellowish to almost black. A glass melt can also acquire an amber color from a reducing combustion atmosphere. Manganese dioxide can be added in small amounts to remove the green tint given by iron(II) oxide. When used in art glass or studio glass is colored using closely guarded recipes that involve specific combinations of metal oxides, melting temperatures and 'cook' times. Most colored glass used in the art market is manufactured in volume by vendors who serve this market although there are some glassmakers with the ability to make their own color from raw materials.

Question: What can give glass a faint green tinge?
Answer: iron(II) oxide

Question: What can prevent a green color in glass?
Answer: Manganese dioxide

Question: What other than additives can give glass a yellow color?
Answer: reducing combustion atmosphere

Question: What chemical compounds can make glass nearly black?
Answer: iron polysulfides

Question: Charged ions can be used to produce what in glass?
Answer: Color
Title: Glass

Glass remained a luxury material, and the disasters that overtook Late Bronze Age civilizations seem to have brought glass-making to a halt. Indigenous development of glass technology in South Asia may have begun in 1730 BCE. In ancient China, though, glassmaking seems to have a late start, compared to ceramics and metal work. The term glass developed in the late Roman Empire. It was in the Roman glassmaking center at Trier, now in modern Germany, that the late-Latin term glesum originated, probably from a Germanic word for a transparent, lustrous substance. Glass objects have been recovered across the Roman empire in domestic, industrial and funerary contexts.[citation needed]

Question: What word does "glass" come from?
Answer: glesum

Question: Where did glasswork begin relatively late?
Answer: China

Question: In what year did glassmaking begin in Asia?
Answer: 1730 BCE

Question: What city was a center of glass production for the Romans?
Answer: Trier

Question: In what current country is Trier located?
Answer: Germany
Title: Glass

Glass was used extensively during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, windows and was also used in jewelry. From the 10th-century onwards, glass was employed in stained glass windows of churches and cathedrals, with famous examples at Chartres Cathedral and the Basilica of Saint Denis. By the 14th-century, architects were designing buildings with walls of stained glass such as Sainte-Chapelle, Paris, (1203–1248) and the East end of Gloucester Cathedral. Stained glass had a major revival with Gothic Revival architecture in the 19th-century. With the Renaissance, and a change in architectural style, the use of large stained glass windows became less prevalent. The use of domestic stained glass increased until most substantial houses had glass windows. These were initially small panes leaded together, but with the changes in technology, glass could be manufactured relatively cheaply in increasingly larger sheets. This led to larger window panes, and, in the 20th-century, to much larger windows in ordinary domestic and commercial buildings.

Question: When did stained glass make a big comeback?
Answer: 19th-century

Question: When did stained glass begin to be used for places of worship?
Answer: 10th-century

Question: When did big windows of stained glass become less common?
Answer: the Renaissance

Question: What 13th-century building is an example of stained glass walls?
Answer: Sainte-Chapelle

Question: What did technological changes allow regular homes to have?
Answer: larger windows
Title: Glass

In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated glass has been widely applied to vehicles for windscreens. While glass containers have always been used for storage and are valued for their hygienic properties, glass has been utilized increasingly in industry. Optical glass for spectacles has been used since the late Middle Ages. The production of lenses has become increasingly proficient, aiding astronomers as well as having other application in medicine and science. Glass is also employed as the aperture cover in many solar energy systems.

Question: What type of glass is used in cars?
Answer: laminated

Question: When did eyeglasses originate?
Answer: late Middle Ages

Question: The walls of skyscrapers are often made of what material?
Answer: glass

Question: What type of power systems use glass?
Answer: solar

Question: What type of scientists rely on glass for distant observations?
Answer: astronomers
Title: Glass

From the 19th century, there was a revival in many ancient glass-making techniques including cameo glass, achieved for the first time since the Roman Empire and initially mostly used for pieces in a neo-classical style. The Art Nouveau movement made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy producing colored vases and similar pieces, often in cameo glass, and also using luster techniques. Louis Comfort Tiffany in America specialized in stained glass, both secular and religious, and his famous lamps. The early 20th-century saw the large-scale factory production of glass art by firms such as Waterford and Lalique. From about 1960 onwards there have been an increasing number of small studios hand-producing glass artworks, and glass artists began to class themselves as in effect sculptors working in glass, and their works as part fine arts.

Question: What famous lampmaker used glass?
Answer: Louis Comfort Tiffany

Question: When did glassworkers begin to consider their products fine art?
Answer: 1960

Question: What type of glass did many Art Nouveau artists use?
Answer: cameo glass

Question: When did mass production of glass art begin?
Answer: early 20th-century

Question: What early civilization made cameo glass?
Answer: Roman Empire