Correlation

About the lecture

In this lecture, we think about correlation, focusing in particular on: (i) what it means for there to be a correlation between datasets; (ii) an example dataset of heights and weights from which to assess a correlational relationship; (iii) a smaller subset of this dataset to further analyse the correlational relationship; (iv) the Pearson’s Product Moment Correlation Coefficient, or Pearson’s r, as an objective measure of correlation; (v) recognising the measures of standard deviation present in the equation for Pearson’s r; (vi) a recap of what standard deviation values mean for a dataset’s characteristics; (vii) breaking down what the denominator and numerator in the Pearson’s r equation mean; (viii) differentiating variance and standard deviation; (ix) understanding covariance to be a measure of how much variance in one variable is matched by variance in another; (x) breaking down the equation used to calculate covariance; (xi) taking the smaller sample dataset and using it to calculate Pearson’s r by calculating the necessary means, standard deviations and covariance; (xii) recapping the function of a t-test, explaining the null and alternative hypotheses; (xiii) working through how to use a t-test to assess the significance of Pearson’s r; (xiv) the value of squaring Pearson’s r, to express the variance of x explained by y.

About the lecturer

Dr Andrew Bell is a lecturer in cognitive neuroscience in the Institute of Psychiatry, Psychology and Neuroscience at King’s College London. Dr Bell works in the neuroimaging department and focuses his teaching on statistics and statistical techniques. Dr Bell is a senior fellow of the Higher Education Academy and has published a review of animal lesion techniques used by researchers of human neuropsychology. Dr Bell’s recent publications include ‘Preserved extrastriate visual network in a monkey with substantial, naturally occurring damage to primary visual cortex’ (2019) and ‘Viewing ambiguous social interactions increases functional connectivity between frontal and temporal nodes of the social brain’ (2021).