A statistical term indicating the ranking of a score on a standardized test If a student scores in the 99th percentile on a test, for example, that means that of all persons tested, only one percent scored higher
The Pth percentile data value is the score that is equal to or greater than P% of all the data values For example, the score equal to the 25th percentile is equal to or greater than one quarter of all the data values (and is also the first quartile) The 50th percentile necessarily is the median
A measure of a 100th part of a population For example, to make comparisons between pension funds easy, performance measurers such as CAPS and WM rank funds into percentiles The top 1% of funds will be in the first percentile, while the bottom 1% will be in the 100th percentile Other similar measures are deciles (one tenth parts of the population) and quartiles (one quarter parts) See also median (the 50th percentile)
A value such that at least p percent of the items are less than or equal to this value and at least (100-p) percent of the items are greater than or equal to this value The 50th percentile is the median
A value on a scale of zero to one hundred that indicates the percent of a distribution that is equal to or below it A score in the 95th percentile is a score equal to or better than 95 percent of all other scores
Any one of the points dividing a distribution of values into parts each of which contain 1/100 of the values For example, the 75th percentile is a value such that 75 percent of the values are less than or equal to it In this assessment, the distribution of values represented (national, state or county percentiles) depends on the presentation format of the results (map, bar chart, or data table)
The pth percentile of a list is the smallest number such that at least p% of the numbers in the list are no larger than it The pth percentile of a random variable is the smallest number such that the chance that the random variable is no larger than it is at least p% C f quantile
A number that corresponds to one of the equal divisions of the range of a variable in a given sample and that characterizes a value of the variable as not exceeded by a specified percentage of all the values in the sample For example, a score higher that 97 percent of those attained is said to be in the 97th percentile
one of 100 equal-sized parts that a group of people can be divided into - used especially when comparing people's scores in a test or levels of health
(statistics) any of the 99 numbered points that divide an ordered set of scores into 100 parts each of which contains one-hundredth of the total
The percentile rank of a score is the percentage of scores in its frequency distribution which are lower. For example, a test score which is greater than 85% of the scores of people taking the test is said to be at the 85th percentile. Percentile ranks are commonly used to clarify the interpretation of scores on standardized tests. For the test theory, the percentile rank of a raw score is interpreted as the percentages of examinees in the norm group who scored below the score of interest (Crocker & Algina, 1986). Percentile ranks (PRs or "percentiles") compared to Normal curve equivalents (NCEs)Unlike a normal distribution of scores, which are bell shaped, the distribution of percentile ranks is uniform and is rectangular in shape. Percentile rank is not an equal-interval scale; that is, the difference between any two scores is not the same between any other two scores. For example, 50 - 25 = 25 is not the same distance as 60 - 35 = 25 because of the bell-curve shape of the distribution. Some percentile ranks are closer to some than others. Percentile rank 30 is closer on the bell curve to 40 than it is to 20 (see [1] and [2] for examples). References Crocker, L., & Algina, J. (1986). Introduction to classical and modern test theory. New York: Harcourt Brace Jovanovich College Publishers.The percentile rank of a score is the percentage of scores in its frequency distribution which are lower. For example, a test score which is greater than 90% of the scores of people taking the test is said to be at the 90th percentile