quartile deviation
- noun
- /ˈkwɔːrtaɪl dɪˈviːeɪʃən/
- Specialized
:
desviación cuartil
- To better understand the variability in the data, we calculated the quartile deviation, which showed how widely the values were spread.
- medians and quartile deviation
Examples
-
A quick look at the medians and quartile deviations reported in Tables 1 and 2 gives a slightly different picture than that seen when simply comparing ranks.
Academic text (1994) -
Table 1 contains the medians, ranks, and quartile deviations of the terminal ends for the 80 students aged 21 or younger and for the 91 students aged 22 or older.
Academic text (1994) -
Medians, Ranks, and Quartile Deviations for Two Age Groups PREFORMATTED TABLE
Academic text (1994) -
The next step is to compute the median (Mdn) and the quartile deviation (Q) of each sexual topic.
Academic text (2006) -
Table 2 contains the medians, ranks, and quartile deviations of the instrumental means for the 80 students aged 21 or younger and for the 91 students aged 22 or older; these data indicate that six instrumental values had a spread of five or more between the rankings of the younger and older students.
Academic text (1994) -
The quartile deviation is an important statistic that helps to measure the spread of data by providing the difference between the first and third quartiles.
-
When analyzing the results, the quartile deviation revealed significant differences in the performance across the three groups.
Surface Forms
Morphology
Knowing 'quartile' (points that split data into quarters) and 'deviation' (a difference) allows a learner to infer that this term denotes a measure of difference or spread related to quartiles, so the general idea is accessible. However, the precise convention that it equals one half of the difference between the first and third quartiles is a technical/statistical detail not directly derivable from the words alone, making the expression only partially predictable.
Etymology
Quartile deviation comes from a simple picture: line up the numbers from small to large and mark the first and third quartiles (the points that split the list into four equal parts). The distance between those two marks, taken as half, is the quartile deviation, so it shows 'how far numbers are from the middle' of the data.
