What is the difference between eysenck's personality inventory and eysenck's personality questionnaire?

Answer 1

I had the same question, but found no answer. Yet, apparently EPQ is a later expanded version of EPI. Another development is EPQ-R, which is the revised version of EPQ.

Answer 2

Eysenck's Personality Inventory (EPI) is a self-report questionnaire that measures personality traits such as extraversion, neuroticism, and psychoticism using a binary response format. Eysenck's Personality Questionnaire (EPQ) is an updated version of the EPI that includes additional scales and uses a Likert scale response format. The EPQ provides a more detailed assessment of personality compared to the EPI.