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Definition
| A statistic is biased if it is calculated in such a way that is systematically different from the population parameter of interest |
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Definition
| Data clustered about two different modes |
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Term
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Definition
| A theorem that gives us information about how many elements of a data set are within a certain number of standard deviations of the mean. |
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Term
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Definition
The difference between a data value and the mean.
Deviation = x - xbar |
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Term
| interquartile range (IQR) |
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Definition
| The inter-quartile range of a list of numbers is the upper quartile minus the lower quartile. |
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Term
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Definition
| With interval measurement, there is significance to the distance between any two values. An example commonly cited for interval measurement is temperature. Does not include the concept of "nothingness" or zero |
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Definition
| A range of values estimated to include the parameter. |
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Term
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Definition
NOIR
Nominal, Ordinal, Interval, Ratio |
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Term
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Definition
| a number (not necessarily a number in the list) such that at least 1/4 of the numbers in the list are no larger than it, and at least 3/4 of the numbers in the list are no smaller than it. |
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Term
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Definition
| Mean of the absolute deviations about the mean. |
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Term
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Definition
| the mean of the maximum and minimum values of the data set. |
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Term
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Definition
| The mean of a sample after a certain percentage of the extreme values are removed |
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Term
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Definition
| A nominal measurement is one in which the values of the variable are names. The names of the different species of Galapagos tortoises are an example of a nominal measurement. |
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Term
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Definition
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Term
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Definition
| An ordinal measurement involves collecting information of which the order is somehow significant. The name of this level is derived from the use of ordinal numbers for ranking (1st, 2nd, 3rd, etc.). In ordinal measurement, the distance between two consecutive values does not have meaning. |
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Term
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Definition
| An extreme point that stands out from the rest of the distribution. |
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Term
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Definition
| A numerical property of a population, such as its mean. |
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Term
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Definition
| The point below which a specified percentage of the observations fall. |
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Term
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Definition
| The specific value taken as the estimate of a parameter. |
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Term
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Definition
| Complete set of events in which you are interested. |
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Term
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Definition
| When a characteristic can be neatly placed into well-defined groups, or categories, that do not depend on order, it is called a categorical variable, or qualitative variable. Qualitative variables are measured on a nominal scale |
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Term
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Definition
| Quantitative variables are measured on an ordinal, interval, or ratio scale |
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Term
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Definition
| the estimation of the ratio between a magnitude of a continuous quantity and a unit magnitude of the same kind. A variable measured at this level not only includes the concepts of order and interval, but also adds the idea of ’nothingness’, or absolute zero. |
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Term
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Definition
A statistic is said to be resistant if corrupting a datum cannot change the statistic much. The mean is not resistant; the median is.
not influenced by the presence of outliers |
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Term
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Definition
| Set of actual observations. Subset of the population. |
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Term
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Definition
| Variability of a statistic from sample to sample due to chance. |
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Term
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Definition
| Square root of the variance. |
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Term
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Definition
| a numerical quantity (such as the mean) calculated in a sample. Such statistics are used to estimate parameters. |
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Term
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Definition
| A trimmed mean is calculated by discarding a certain percentage of the lowest and the highest scores and then computing the mean of the remaining scores. For example, a mean trimmed 50% is computed by discarding the lower and higher 25% of the scores and taking the mean of the remaining scores. |
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Term
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Definition
| Each member of the population |
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Term
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Definition
| a number such that at least 3/4 of the entries in the list are no larger than it, and at least 1/4 of the numbers in the list are no smaller than it. |
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Term
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Definition
| Properties of objects that can take on different values. |
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Term
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Definition
| The sum of the squared deviations from the mean, divided by the degrees of freedom (N- 1). |
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Term
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Definition
| Row or column means where the cell sizes are used to weight the cell means. |
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