Flashcards
Elementary Statistics
Cards in this deck (29)
- 1Populationthe complete collection of all measurements or data that are being considered
- 2Censusthe collection of data from every member of the population
- 3Sampleis a subcollection of members selected from a population
- 4Parametera numerical measurement describing some characteristic of a population (p for population)
- 5Statistic-is a numerical measurement describing some characteristic of a sample (s for sample)
- 6Voluntary Response sample-(or self-selected sample) is one in which the respondents themselves decide whether to be included
- 7observational studywe observe and measure specific characteristics, but we don’t attempt to modify the subjects being studied
- 8Expirementwe apply some treatment and then proceed to observe its effects on the subjects (subjects in experiments are called experimental units)
- 9Placebo effectwhich occurs when an untreated subject reports an improvement in symptoms
- 10blindingis in effect when the subject doesn’t know whether he or she is receiving a treatment or a placebo
- 11confoundingoccurs in an experiment when the investigators are not able to distinguish among the effects of different factors (you don’t want this)
- 12sampling erroroccurs when the sample has been elected w a random method, but there is a discrepancy between a sample results and the true population result; such an error results from chance sample fluctuations
- 13nonsampling erroris the result of human error, including such factors as wrong data entries, computing errors, questions w biased wording, false data provided by respondents, forming biased conclusions, or applying statistical methods that are not appropriate for the circumstances
- 14discretei. Result when the data values are quantitative and the number of values is finite or “countable”.
- 15continuousi. Result from infinitely many possible quantitative values, where the collection of values is not countable.
- 16nominala. Characterized by data that consist of names, labels, or categories only. The data cannot be arranged in an ordering scheme such as low to high.
- 17ordinala. If they can be arranged in the same order, but differences (by subtraction) between data values either cannot be determined or are meaningless
- 18intervala. If they can be arranged in order, and differences between data values can be found and are meaningful.
- 19ratioa. If they can be arranged in order, differences can be found and are meaningful, and there is a natural zero starting point. For this data, differences and ratios are both meaningful.
- 20a. How do a parameter and a statistic differ?i. A parameter is a numerical measurement describing some characteristic of a population, whereas a statistic is a numerical measurement describing some characteristic of a sample.
- 21a. Random sampling:i. Each member of the population has an equal chance of being selected
- 22b. Simple random sampling:i. A sample of n subjects is selected in such a way that every possible sample of the same size n has the same chance of being chosen
- 23c. Systematic sampling:i. Select some starting point, then select every kth (such as every 50th) element in the population
- 24d. Convenience sampling:i. Use results that are easy to get
- 25e. Stratified sampling:i. Subdivide the population into at least two diff. subgroups so that subjects within the same subgroup share the same characteristics, then draw a sample from each subgroup
- 26f. Cluster sampling:i. Divide the population into sections, then randomly select some of those clusters, and then choose all members from those selected clusters.
- 275 # summary:max value
median
min value - 285 characteristics of data:Variation, Center, Distribution, ??
- 29z scorenumber of standard deviations that a given value is above or below the mean
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- Elemetary Statistics Flashcards on Elementary Statistics, created by Brooke Sullivan on 19/01/2019.
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- Brooke Sullivan
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