The Importance of Descriptive Statistics

Statistics for Psychologists – Descriptive Statistics

In this course, Professor Dominic Dwyer (Cardiff University) explores descriptive statistics. In the first lecture, we think about why descriptive statistics are important. In the second lecture, we think about the mode and its representation of the most common score. In the third lecture, we think about the median and how it is only minimally sensitive to outlying scores. Next, we think about the mean and standard deviation, exploring how to calculate each one. In the fifth and final lecture, we think about how these different measures of central tendency and dispersion can be appropriate for different datasets.

The Importance of Descriptive Statistics

In this lecture, we think about why we need descriptive statistics, focusing in particular on: (i) the breadth of information that can be collected during a psychology study, which descriptive statistics can serve to summarise; (ii) the common pairing between descriptive statistics and visual representations of data, such as graphs; (iii) defining the central tendency as understanding where the data clusters together; (iv) defining dispersion of data, which refers to how spread out the data is, or ‘how typical is typical’; (v) the three most commonly used measures of central tendency being the arithmetic mean, the median, and the mode; (vi) three commonly used measures of dispersion being the standard deviation, the range, and the interquartile range.