3. Validity

About this Lecture

Lecture

In this lecture, we think about internal and external validity, focusing in particular on: (i) defining validity as effectively ensuring that a study is measuring what it should be measuring, and what the researcher thinks it is measuring; (ii) some questionable examples of how someone might assess antisocial personality qualities, challenging the internal validity of these proposed measures; (iii) an example of a measure with good internal validity, contextualised in a study on depression; (iv) external validity, discussed in the context of an unintended social experiment in 1985 – ‘New Coke’; (v) an example of a study on helping in the event of an emergency with good external validity and the application of this logic to psychology as a whole.

Glossary:

Validity – The extent to which a study or measure truly assesses what it intends/claims to.

Course

In this course, Dr Ayoub Bouguettaya (University of Birmingham) explores a key shortcoming in the field of psychological science – replication. In the first lecture, we explore the concept of replication and define science in terms of three key criteria: reliable and valid theory which can predict outcomes, theories that can be disproven by quantifiable experimentation, and theories that are altered or withdrawn in the light of new findings. In the second lecture, we explore reliability and outline three core issues facing psychological science: quantifiable measures, theories that cannot be disproven, and unrefined theories. In the third and fourth lectures, we explore the definition of validity, its variety of forms, and the challenges associated with formulating valid research. Next, we think about the interrelatedness of validity and reliability, as well as returning to this idea of replication and the many famous studies which have failed either conceptual or exact replication. In the sixth and final lecture, we think about the ways in which the field of psychology is tackling these problems and conclude on two different perspectives on whether psychology can be considered a true science.

Lecturer

Dr Ayoub Bouguettaya is a lecturer in the School of Psychology at the University of Birmingham. Dr Bouguettaya’s research interests are in social psychology and how knowledge from that field can be applied to others, particularly health, including how we can apply social identity theory to societal problems, as well as investigating the different perspectives one might take on those issues. Some of Dr Bouguettaya’s recent publications include 'The relationship between gambling advertising and gambling attitudes, intentions and behaviours: a critical and meta-analytic review' (2020) and 'The Effect of a Food Addiction Explanation Model for Weight Control and Obesity on Weight Stigma' (2020).