Interquartile range refers to the interval of scores bounded by the 25th and the 75th percentiles.
The interquartile range (IQR) is a statistical measure used in psychology and other fields to describe the spread or variability of a data set. It is the difference between the third quartile (Q3) and the first quartile (Q1) of a distribution, and represents the middle 50% of the data.
Here are some examples of how the interquartile range might be used in psychology:

In a study of depression scores in a sample of college students, the interquartile range might be used to describe the range of scores within the middle 50% of the sample. For example, if the IQR is 10 points, this would mean that the scores for 50% of the sample fell between Q15 and Q3+5.

In a study of reaction times to a cognitive task, the interquartile range might be used to describe the variability of the data. A smaller IQR would suggest that the data is more tightly clustered around the median, while a larger IQR would suggest that the data is more spread out.

In a study of anxiety symptoms in a clinical sample, the interquartile range might be used to identify outliers or extreme scores that fall outside of the middle 50% of the data. This could be useful for identifying individuals who may require more intensive treatment or support.
Overall, the interquartile range is a useful statistical tool for describing the variability of a data set, and can be used in a wide range of psychological research and applications.