What change in each measure/scale might I expect?


Personal Questionniare

Decrease of 1.67 or more to an original average rating of 3.25 or more.1

Strathclyde Inventory

Increase of 0.462 or more to an original score of 2.52 or less.3

Process Continuum Scale

Increase of around 1 or 2 to original average score.4


1See Robert Elliott, John Wagner, Celia Sales, Brian Rodgers, Paula Alves and Maria Cafe, ‘Psychometrics of the Personal Questionnaire: A Client-generated Outcome Measure’, Psychological Assessment 28:3 (2016): 271.

2See Susan Stephen, Robert Elliott and Rachel Macleod, ‘Person-Centred Therapy with a Client Experiencing Social Anxiety Difficulties: A Hermeneutic Single Case Efficacy Design’, Counselling and Psychotherapy Research 11:1 (2011): 65.

3See Emmanuelle Zech, Céline Brison, Robert Elliott, Brian Rodgers and Jeffrey Cornelius-White, ‘Measuring Rogers’ Conception of Personality Development: Validation of the Strathclyde Inventory-French Version’, Person-Centred and Experiential Psychotherapies 17:2 (2018): 171.

4See Carl Rogers, ‘A Process Conception of Psychotherapy’ in On Becoming a Person: A Therapist’s View of Psychotherapy (London: Constable: 1961) 155-6.