Willem J. Heiser

Understanding the differential impact of outcome monitoring: Therapist variables that moderate feedback effects in a randomized clinical trial

Kim de Jong, Patricia van Sluis, Annet Nugter et al. · Psychotherapy Research · 2012 · 243 citations

Psychotherapy, Treatment Effect, Therapist Variables +23

The Outcome Questionnaire (OQ‐45) in a Dutch population: A cross‐cultural validation

Kim de Jong, Annet Nugter, Marike Polak et al. · Clinical Psychology & Psychotherapy · 2007 · 198 citations

Quality Of Life, Family Medicine, Psychological Co-morbidities +26

Neuroticism, alexithymia, negative affect, and positive affect as determinants of medically unexplained symptoms

Véronique De Gucht, Benjamin Fischler, Willem J. Heiser · Personality and Individual Differences · 2003 · 144 citations

Psychiatry, Emotion Regulation, Mood Symptom +14

Avoiding Degeneracy in Multidimensional Unfolding by Penalizing on the Coefficient of Variation

Frank Busing, Patrick J. F. Groenen, Willem J. Heiser · Psychometrika · 2005 · 136 citations

Cluster Differences Scaling with a Within-Clusters Loss Component and a Fuzzy Successive Approximation Strategy to Avoid Local Minima

Willem J. Heiser, Patrick J. F. Groenen · Psychometrika · 1997 · 96 citations