NC.M3.S-IC.3
Recognize the purposes of and differences between sample surveys, experiments, and observational studies and understand how randomization should be used in each.
Example Problems
The parks department will repaint 5 of 50 trail markers. They number the markers and use the random digit table printed below to choose a simple random sample.
Which markers are in the sample?
Which markers are in the sample?
A research lab prepared 33 culture plates and will test a simple random sample of 5. The plates are numbered 01-33 and the random digit table printed below is used.
Which plates are in the sample?
54140, 32930, 21965, 40788, 15302
Which plates are in the sample?
54140, 32930, 21965, 40788, 15302
A teacher has 10 group leaders and needs a simple random sample of 3 to present first. He numbers them and uses the random digit table printed below.
Which leaders are in the sample?
Which leaders are in the sample?
Khan Academy ResourcesThe language of experimentsPrinciples of experiment designSimulation and randomness: Random digit tablesRandom sampling vs. random assignment (scope of inference)Sampling methodsConclusions in observational studies versus experimentsSimple random samplesExperiment designsSampling method considerationsExperiment design considerationsTypes of studiesFinding errors in study conclusionsSystematic random samplingMatched pairs experiment designIntroduction to experiment designInvalid conclusions from studies exampleCan causality be established from this study?Techniques for random sampling and avoiding biasWorked example identifying observational studyTechniques for generating a simple random sampleTypes of studies
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