Extract the answer to the question from the following context. Question: What methods works from the principle that a community of errors implies community of origin? Context: Stemmatics, stemmology or stemmatology is a rigorous approach to textual criticism. Karl Lachmann (17931851) greatly contributed to making this method famous, even though he did not invent it. The method takes its name from the word stemma. The Ancient Greek word and its loanword in classical Latin stemmata may refer to "family trees". This specific meaning shows the relationships of the surviving witnesses (the first known example of such a stemma, albeit with the name, dates from 1827). The family tree is also referred to as a cladogram. The method works from the principle that "community of error implies community of origin." That is, if two witnesses have a number of errors in common, it may be presumed that they were derived from a common intermediate source, called a hyparchetype. Relations between the lost intermediates are determined by the same process, placing all extant manuscripts in a family tree or stemma codicum descended from a single archetype. The process of constructing the stemma is called recension, or the Latin recensio.
Ans: Stemmatics

Extract the answer to the question from the following context. Question: What does the A in IESNA stand for? Context: The Illuminating Engineering Society of North America (IESNA), in conjunction with organizations like ANSI and ASHRAE, publishes guidelines, standards, and handbooks that allow categorization of the illumination needs of different built environments. Manufacturers of lighting equipment publish photometric data for their products, which defines the distribution of light released by a specific luminaire. This data is typically expressed in standardized form defined by the IESNA.
Ans: America

Extract the answer to the question from the following context. Question: What is at the terminus of the trail? Context: In eastern Pennsylvania the Great Appalachian Valley, or Great Valley, was accessible by reason of a broad gateway between the end of South Mountain and the Highlands, and many Germans and Moravians settled here between the Susquehanna and Delaware Rivers forming the Pennsylvania Dutch community, some of whom even now speak a unique American dialect of German known as the "Pennsylvania German language" or "Pennsylvania Dutch." These latecomers to the New World were forced to the frontier to find cheap land. With their followers of both German, English and Scots-Irish origin, they worked their way southward and soon occupied all of the Shenandoah Valley, ceded by the Iroquois, and the upper reaches of the Great Valley tributaries of the Tennessee River, ceded by the Cherokee.
Ans: the end of South Mountain and the Highlands

Extract the answer to the question from the following context. Question: Despite victory, what wa sa concern? Context: Airborne Interception radar (AI) was unreliable. The heavy fighting in the Battle of Britain had eaten up most of Fighter Command's resources, so there was little investment in night fighting. Bombers were flown with airborne search lights out of desperation[citation needed], but to little avail. Of greater potential was the GL (Gunlaying) radar and searchlights with fighter direction from RAF fighter control rooms to begin a GCI system (Ground Control-led Interception) under Group-level control (No. 10 Group RAF, No. 11 Group RAF and No. 12 Group RAF).
Ans: The heavy fighting in the Battle of Britain had eaten up most of Fighter Command's resources