Dreifingareiningar

Dreifingareiningar is the Icelandic term for measures of dispersion in statistics, describing how data are spread around a central value such as the mean or median. These measures complement indicators of central tendency and provide information about variability in a dataset.

Common dreifingareiningar include the range, interquartile range (IQR), variance, standard deviation, and the coefficient of variation (CV). The range is the difference between the maximum and minimum values. The IQR is the difference between the 75th and 25th percentiles and reflects the spread of the middle half of the data. Variance measures the average squared deviation from the mean, while standard deviation is the square root of the variance and has the same units as the data. The CV expresses dispersion relative to the mean by dividing the standard deviation by the mean and is often shown as a percentage. Robust measures such as the median absolute deviation (MAD) can be used when data contain outliers.

Interpretation of dreifingareiningar requires attention to scale and context. Some measures are sensitive to outliers (range, variance, standard deviation), while others (IQR, MAD) are more robust. The choice of measure depends on the data distribution, the presence of outliers, and whether unit comparability is needed. In practice, dreifingareiningar are used to compare variability across datasets, assess measurement precision, and inform statistical modeling and quality control.