Descriptive statistics include measures of central tendency and variability. Measures of central tendency include mean, median, and mode. The mean is the arithmetic average of data from interval or ratio scales. The median reflects the 50th percentile score. The mode is the most frequently occurring value of a data distribution. Measures of variability include range, interquartile range, standa...

Linda Shields PhD, FRCNA, Professor of Nursing, University of Limerick, Ireland This is one of a series of short papers on aspects of research by Alison Twycross and Linda Shields You’ve found a piece of research that you think may be relevant to your practice but it is full of statistics and you can make neither head nor tail of them. Why do researchers bother doing statistical tests? What on ...