About the lecture

In this lecture, we think about ratio data and scales, focusing in particular on: (i) the importance of zero meaning something (nothing in this case) in ratio scales; (ii) the role that measurement units have in ratio scales, meaning that the scale can be validly represented in a variety of ways; (iii) the key notion that, irrespective of the measurement unit used, the difference between value points is always the same ratio; (iv) the history of measurement pre-Steven’s measurement levels, which indicated that ratio measurement was understood simply as measurement; (v) the notion that everything which is true of a ‘lower’ measurement scale is true of a ‘higher’ one.

About the lecturer

Professor Dominic Dwyer is the chair for the BSc and MSc exam boards in the School of Psychology at Cardiff University. Professor Dwyer teaches introductory statistics for undergraduate years one and two. Professor Dwyer’s research is primarily focused on how animals and people learn, as well as how that learning is expressed as behaviour. Some key focus areas of this research are computational modelling, neurodegenerative disorders, and the assessment of individual differences. Some of Professor Dwyer’s recent publications include 'EXPRESS: Instrumental responses and Pavlovian stimuli as temporal referents in a peak procedure' (2022) and 'Face masks have emotion-dependent dissociable effects on accuracy and confidence in identifying facial expressions of emotion' (2022).