populations Because it is impossible to count all the members of a large community‚ some form of sampling has to be used. The size of the sample depends on the area to be investigated‚ but can be shown on a graph as shown (right): Beyond this point‚ more samples (= more work) does not increase the reliability of the results. Ideal sample size AQA are very keen that you should know the importance of random sampling. This is essential to avoid bias. In fieldwork‚ this is done by: 1. Lay out two tapes at
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Petit: Sane Wire Walker What do you think when you imagine a man walking on a wire higher than 10 stories high? A French wire walker named Philippe Petit walked over many structures from Notre Dame to Sydney‚ Australia‚ to New York. Through the things he has done‚ people may think he is crazy. However‚ Petit and I think that there is nothing crazy about what he has done. I believe the people/society thinks he is crazy. They see this man up hundreds of feet walking across a wire over famous
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A Practical Guide to Sampling Statistical & Technical Team This guide is brought to you by the Statistical and Technical Team‚ who form part of the VFM Development Team. They are responsible for advice and guidance on quantative‚ analytical and technical issues. For further information about the matters raised in this guide‚ please contact: Alison Langham on ext. 7171 This guide is the latest in a series on sampling. It has been produced in response to a large number of requests
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The resistance of a wire Planning:- Introduction: To investigate the resistance of a wire at different lengths to see whether or not a longer wire has a larger resistance than a shorter wire. Apparatus: Wire Voltmeter Ammeter Battery 2 crocodile clips Metre rule Variable resistor Diagram: Variables: Length Thickness Resistance Material The material and diameter of the wire needs to be kept constant to keep the test fair as we are investigating resistance. The
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Application of sampling distribution Joe Greene‚ a new manager at Pilgrim Bank wants to better understand profitability data for bank’s customers. Joe is able to obtain a random sample of 31‚634 customers on the following variables – Profitability (in $‚ for the most recent completed year‚ i.e. 2006)‚ whether or not the customer uses the online banking channel‚ customer tenure‚ age and income where available‚ as well as the customer’s residential area. Descriptive statistics for Profits indicates
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did a great job of depicting just how much Philippe appreciated every minute of his life. Philippe not only enjoyed the planning of his wire walk and the adrenaline rush of having to tiptoe around all the security guards patrolling the towers‚ but also the act of setting everything up. We can see this in his expressions‚ during his first few minutes on the wire his face shows complete concentration and then only a few moments later he is peaceful‚ the euphoric expressions on his face tell the story
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Random sampling is the purest form of probability sampling. Each member of the population has an equal and known chance of being selected. When there are very large populations‚ it is often difficult or impossible to identify every member of the population‚ so the pool of available subjects becomes biased. Systematic sampling is often used instead of random sampling. It is also called an Nth name selection technique. After the required sample size has been calculated‚ every Nth record is selected
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Sampling methodologies Sampling It may be defined as a process of selecting units that may be people‚ organizations etc‚ from a larger whole i.e. from a population of interest‚ so that by studying the sample we may come up with general characteristics of the entire population under consideration. Types of sampling methods: Probability sampling Probability sampling is a type of sampling that includes random selection. And in order to achieve random selection‚ it must be
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SAMPLING Sampling is the act‚ process‚ or technique of selecting a suitable sample‚ or a representative part of a population for the purpose of determining parameters or characteristics of the whole population. REASONS FOR SAMPLING There are six main reasons for sampling instead of doing a census. These are; * Economy * Timeliness * The large size of many populations * Inaccessibility of some of the population * Destructiveness of the observation * Accuracy or Reliability
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Hello Garci Scandal "Hello Garci" refers to the alleged wiretapped conversations where vote rigging in the 2004 elections was discussed by‚ among others‚ a woman presumed to be President Arroyo and man presumed to be Comelec Commissioner Virgilio Garcillano. Ironically‚ the controversy that nearly toppled the Arroyo administration started at the Palace‚ when Presidential Spokesperson Ignacio Bunye released CDs of the Hello Garci conversations on June 6‚ 2005. Days later‚ former NBI Deputy Director
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