Emerson Bartholomew
Psychometrician & Research Fellow, NovoPsych
MHealthPsych (Hons)
Emerson Bartholomew is a psychometrician and research fellow at NovoPsych, where he leads the development and validation of new psychological assessments. He has published 12 peer-reviewed journal articles and a book chapter, and has five years' experience in the development, validation and enhancement of psychological and patient-reported outcome measures. His work appears in journals including Rheumatology, the Journal of Psychosomatic Research, Mindfulness and the International Journal of Stress Management.
He specialises in Rasch measurement and item response theory, the family of methods used to establish how precisely a scale measures, whether its items behave the same way for different groups of people, and whether scores keep their meaning across languages and clinical populations.
Areas of expertise
Psychometrics. The development and validation of psychological and patient-reported outcome measures; cross-cultural validity, measurement invariance; differential item functioning; item reduction; and applied machine learning for measurement problems.
Recent articles by Emerson Bartholomew
Adult ADHD Observer-Report Scale (ASRS-O)
Ruminative Responses Scale (RRS)
Dimensions of Anger Reactions (DAR-5)
Education
A graduate of the Master of Health Psychology programme in the Department of Psychological Medicine, within the Faculty of Medical and Health Sciences at the University of Auckland.
Professional experience
Emerson joined NovoPsych in 2024, where he leads the development of new assessments and the psychometric review of instruments already in the library. He is a co-author of the Maladaptive Schema Scale (MSS), a 108-item measure of 27 maladaptive schemas used in schema-focused case formulation and available through NovoPsych.
Before NovoPsych he directed projects in collaboration with King's College London, the Maudsley NHS Trust and the Persistent Physical Symptoms Research and Treatment Unit, evaluating patient-reported measures of fatigue, depression, anxiety, stress and disability in patients with rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis, and producing improvements to measurement accuracy for their use in clinical settings.
He reviews for a range of journals in psychology, measurement and health services research, among them Mindfulness, Vaccine, the International Journal of Stress Management, Scientific Reports, Health and Quality of Life Outcomes, the Journal of Patient-Reported Outcomes and Language Testing in Asia, along with seven BMC titles.
Selected peer-reviewed publications
- Adu, P., Bartholomew, E., & Medvedev, O. N. (2026). Rasch methodology for assessment in international contexts. In International Handbook of Behavioral Health Assessment. Springer Nature.
- Bartholomew, E., Krägeloh, C., Milfont, T. L., & Medvedev, O. N. (2026). Measuring perceived stress in 25 languages using a universal metric derived from a Rasch model. International Journal of Stress Management.
- Adu, P., Attiah, N. A. K., Bartholomew, E., & Jurcik, T. (2026). Enhancement of the measurement precision and interval-level scaling of the General Self-Efficacy Scale (GSE) using Rasch analysis. Current Psychology.
- Buchanan, B., Bartholomew, E., Smyth, C., & Hegarty, D. (2025). The Maladaptive Schema Scale (MSS): Development and Validation of a Comprehensive Questionnaire for Beliefs Related to Psychopathology. Assessment, 10731911251390083. Advance online publication. https://doi.org/10.1177/10731911251390083
- Bartholomew, E., Medvedev, O. N., Petrie, K. J., & Chalder, T. (2025). Rasch analysis of the Hospital Anxiety and Depression Scale in patients with chronic fatigue syndrome. Journal of Psychosomatic Research, 197, 112370.
- Bartholomew, E., Verster, J. C., Cervin, M., … Medvedev, O. N. (2025). Establishing the cross-cultural validity of the Immune Status Questionnaire using Rasch analysis. International Journal of Psychology. https://doi.org/10.1002/ijop.70051
- Adu, P., Popoola, T., Bartholomew, E., Iqbal, N., Medvedev, O. N., & Simpson, C. R. (2025). Enhancing the precision of the Revised Life Orientation Test (LOT-R) across Germany, Ghana, India and New Zealand using Rasch methodology. Social Indicators Research, 179, 505–525.
- Adu, P., Popoola, T., Bartholomew, E., … Simpson, C. R. (2024). Enhancing the precision of the Self-Compassion Scale Short Form (SCS-SF) with Rasch methodology. Mindfulness, 15, 2779–2793.
- Bartholomew, E., Medvedev, O. N., Petrie, K. J., & Chalder, T. (2024). Which fatigue scale should I use? A Rasch analysis of two fatigue scales in inflammatory conditions. Rheumatology. https://doi.org/10.1093/rheumatology/kead667
- Bartholomew, E., Roemer, A., & Medvedev, O. N. (2023). Validation and enhancement of the 6-item Nature-Relatedness Scale using Rasch analysis. Ecopsychology, 15(1), 81–90.
- Bartholomew, E., Iqbal, N., & Medvedev, O. N. (2022). Enhancing the assessment of gratitude in mindfulness research: A Rasch analysis of the 6-item Gratitude Questionnaire. Mindfulness, 13, 3017–3027.
Contribution to NovoPsych
As psychometrician and research fellow, Emerson is responsible, along with the rest of the psychometrics team, for the measurement science behind NovoPsych's assessments. He designs validation programs for new instruments, evaluates the psychometric properties of established ones, and translates that evidence into the norms, thresholds and interpretive guidance clinicians rely on.
“The power of psychometrics is not about numbers, but the insights and clarity created for practitioners, helping them make a real difference in client care.”