Not quite normal: Consequences of violating the assumption of normality in regression mixture models

Structural Equation Modeling : a Multidisciplinary Journal
M Lee Van HornGeorge Howe


Regression mixture models are a new approach for finding differential effects which have only recently begun to be used in applied research. This approach comes at the cost of the assumption that error terms are normally distributed within classes. The current study uses Monte Carlo simulations to explore the effects of relatively minor violations of this assumption, the use of an ordered polytomous outcome is then examined as an alternative which makes somewhat weaker assumptions, and finally both approaches are demonstrated with an applied example looking at differences in the effects of family management on the highly skewed outcome of drug use. Results show that violating the assumption of normal errors results in systematic bias in both latent class enumeration and parameter estimates. Additional classes which reflect violations of distributional assumptions are found. Under some conditions it is possible to come to conclusions that are consistent with the effects in the population, but when errors are skewed in both classes the results typically no longer reflect even the pattern of effects in the population. The polytomous regression model performs better under all scenarios examined and comes to reasonable results with ...Continue Reading


Mar 16, 1990·Science·P L Ellickson, R M Bell
Mar 21, 1998·Child Development·G H Elder
Oct 8, 1999·The American Psychologist·T J DishionF Poulin
Nov 26, 1999·American Journal of Community Psychology·S G KellamEve K Mościcki
Aug 6, 2002·Science·Avshalom CaspiRichie Poulton
Aug 23, 2003·Biostatistics·Bengt MuthénJason Liao
Dec 16, 2003·Cognitive, Affective & Behavioral Neuroscience·Jennifer D Ryan, Neal J Cohen
Dec 21, 2005·Prevention Science : the Official Journal of the Society for Prevention Research·Brian R FlayPeter Ji
Jun 23, 2006·Prevention Science : the Official Journal of the Society for Prevention Research·Richard SpothKari Azevedo
Jul 24, 2008·Substance Use & Misuse·Karol L KumpferJulia Franklin Summerhays
May 11, 2010·Clinical Research in Cardiology : Official Journal of the German Cardiac Society·T LambertR Hofmann
Apr 1, 2008·Multivariate Behavioral Research·M Lee Van HornRichard F Catalano


Oct 24, 2014·Journal of Quantitative Criminology·Abigail A FaganThomas Jaki
Jun 28, 2016·Structural Equation Modeling : a Multidisciplinary Journal·Veronica T Cole, Daniel J Bauer
Nov 12, 2015·Educational and Psychological Measurement·M Lee Van HornMinjung Kim
Jan 1, 2019·Multivariate Behavioral Research·Kathryn S Macia, Robert E Wickham
Jun 6, 2014·Journal of Developmental Origins of Health and Disease·M S GilthorpeE Goodman
Jun 4, 2019·Behavior Research Methods·Minjung KimAndrew J Bush
Jul 3, 2019·Multivariate Behavioral Research·Veronica T ColeAndrea M Hussong
Nov 1, 2013·Multivariate Behavioral Research·Melissa R W GeorgeM Lee Van Horn
Oct 28, 2017·Structural Equation Modeling : a Multidisciplinary Journal·Veronica T ColeMichael L Giordano
Dec 12, 2018·Communications in Statistics: Simulation and Computation·Thomas JakiM Lee Van Horn
Dec 5, 2019·The Journal of the Acoustical Society of America·Junjie ShiQingyu Liu
Apr 20, 2020·Prevention Science : the Official Journal of the Society for Prevention Research·Albert J Burgess-Hull
Mar 27, 2019·Educational and Psychological Measurement·Thomas JakiM Lee Van Horn
Jan 1, 2016·Structural Equation Modeling : a Multidisciplinary Journal·Kim MinjungVan Horn M Lee
Apr 17, 2020·Quality of Life Research : an International Journal of Quality of Life Aspects of Treatment, Care and Rehabilitation·Andreas Westh VilsbøllCathrine Elgaard Jensen

Related Concepts

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Hereditary Sensory Autonomic Neuropathy

Hereditary Sensory Autonomic Neuropathies are a group of inherited neurodegenerative disorders characterized clinically by loss of sensation and autonomic dysfunction. Here is the latest research on these neuropathies.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.

Glut1 Deficiency

Glut1 deficiency, an autosomal dominant, genetic metabolic disorder associated with a deficiency of GLUT1, the protein that transports glucose across the blood brain barrier, is characterized by mental and motor developmental delays and infantile seizures. Follow the latest research on Glut1 deficiency with this feed.

Separation Anxiety

Separation anxiety is a type of anxiety disorder that involves excessive distress and anxiety with separation. This may include separation from places or people to which they have a strong emotional connection with. It often affects children more than adults. Here is the latest research on separation anxiety.

KIF1A Associated Neurological Disorder

KIF1A associated neurological disorder (KAND) is a rare neurodegenerative condition caused by mutations in the KIF1A gene. KAND may present with a wide range and severity of symptoms including stiff or weak leg muscles, low muscle tone, a lack of muscle coordination and balance, and intellectual disability. Find the latest research on KAND here.

Regulation of Vocal-Motor Plasticity

Dopaminergic projections to the basal ganglia and nucleus accumbens shape the learning and plasticity of motivated behaviors across species including the regulation of vocal-motor plasticity and performance in songbirds. Discover the latest research on the regulation of vocal-motor plasticity here.