STATISTICAL SOFTWARE
AMOS SEM Analysis Service
Covariance-Based Models With Documented Fit
Our AMOS SEM analysis service carries out confirmatory factor, path and structural equation models in AMOS, working from your data and model files, with the path diagram, estimates and fit reporting delivered where agreed so that the model and its revisions can be reopened and checked.
No Commitment Required
Strictly Confidential
In-House PhD-Level Statisticians
Fixed Project Fee
Same-Day Response
What Is AMOS Used For in Research?
AMOS (IBM SPSS Amos) is software for covariance-based structural equation modeling, in which the model is drawn as a path diagram and estimated from the covariance structure of the data. Researchers choose it for confirmatory factor analysis, path analysis and structural models with continuous indicators, and for its fit with IBM SPSS data files. Drawing makes a model easy to specify and just as easy to over-adjust, because fit can be improved with modification indices without any theoretical reason. OnlineSPSS, a specialist statistical consultancy for academic, clinical and professional research, provides an AMOS SEM analysis service in which an in-house PhD-level statistician carries out the agreed models in AMOS, working from your files.
WHEN TO ENGAGE
Four Reasons Researchers Bring Us an AMOS Model
Requests come with a model ready for estimation, a poor fit that invites easy fixes, a diagram without documentation or a question about effects and groups.
Theory-Ready Model to Estimate The measurement model comes from a published instrument and the paths from your hypotheses, and both have to be estimated in AMOS and reported with standardized estimates beside several fit indices.
Poor Fit and Pressure to Adjust A model fits poorly and modification indices suggest correlated errors, so the decision about what is justified is made from measurement and theory, not from the size of an index.
Diagram Without Documentation An AMOS diagram circulates between coauthors without its constraints, estimation settings or sample behind it, and the model has to be reconstructed and documented.
Indirect Effects or Group Questions Indirect effects or differences between groups must be tested, which in AMOS means bootstrapped effects or multigroup models that are set up and compared with care.
ANALYSES IN AMOS
Analyses Carried Out in AMOS for Your Latent Models
AMOS structural equation modeling covers a family of related models, and each card below links to the method page where the choice between them is explained.
Structural Equation Modeling (SEM)
A measurement model is established first and the structural paths are added afterward, with standardized estimates and several fit indices reported, never one cutoff alone.
Confirmatory Factor Analysis (CFA)
AMOS CFA analysis examines loadings, residual variances and factor correlations, with convergent and discriminant validity judged from the structure and the theory.
Path Analysis
AMOS path analysis of observed variables is checked for identification, with direct and indirect effects reported with intervals and the limits of causal reading stated.
Mediation Analysis
Each indirect effect is tested with a bootstrapped interval, and where several mediators are involved, the specific indirect effects are defined one by one, because AMOS reports only their total by default.
Measurement Invariance
Multigroup models are fitted in sequence, from the same structure in each group to equal loadings and intercepts, with the change in fit judged at each step.
Latent Growth Curve Modeling (LGM)
Intercept and slope factors are specified for repeated measures with the time coding stated, and the growth means, variances and their covariance are reported.
COMMON AMOS ISSUES
Where AMOS Models Go Wrong Before the Fit Indices
A path diagram makes every change easy to make, so the faults that matter are the ones introduced in pursuit of fit, and each check below is made before a model is reported.
Modification Indices Read in Context AMOS lists every index above a threshold of 4 by default, and freeing the largest one run after run fits the model to one sample. A change is kept only with a reason in item wording or theory, and is logged.
Identification A model needs enough information, and each latent variable needs a scale. Degrees of freedom and fixed loadings are checked before estimation, since an unidentified model can return meaningless numbers.
Standardized Loadings and Residuals Standardized loadings and residual covariances are read together, and weak indicators or negative error variances are traced to their cause instead of being constrained away.
Several Fit Indices Together Chi-square, CFI, TLI and RMSEA with its interval are read together against the model and the sample, because no one index and no universal cutoff settles whether a model is acceptable.
Non-Normal Data and Estimation Maximum likelihood assumes multivariate normality, so kurtosis is examined first, and where it is marked, the Bollen-Stine bootstrap p-value and bootstrapped standard errors replace the normal-theory ones.
Ordinal Indicators Likert items with few categories treated as continuous can bias estimates, so the number of categories and the distribution decide whether the model stays in AMOS.
DELIVERABLES
What You Receive From an AMOS Analysis
The files follow a documented AMOS project, agreed in the scope and provided where applicable, so that the model and every revision of it can be reopened and checked.
Model File and Path Diagram The AMOS model file and the diagram as estimated, with constraints and labels visible, so that the specification can be inspected on screen.
Estimates Output Unstandardized and standardized estimates with standard errors and intervals, exported from the final model and each earlier model reported.
Model Revision Log A log of each change from the first specification to the final model, with the reason for it, so that no modification is made without a record.
Prepared Data File The data file the model was run on, with variable names and codes documented and the handling of missing values stated.
Fit and Reporting Tables Publication-ready tables and figures with fit indices, loadings and path estimates, and the sample size and the estimation method named beside each model.
Statistical Interpretation Paths, loadings and fit are explained within what the design allows, with equivalent models named, so reviewers can see what was confirmatory and what was not.
OTHER PLATFORMS
When Another Platform May Be More Appropriate
AMOS suits covariance-based models with continuous indicators, and a project that needs more complex estimators or another team's standard may belong elsewhere.
ILLUSTRATIVE EXAMPLE
How an AMOS Analysis May Look in Practice
An illustration of how a measurement model with a poor first fit moves to a model whose every change has a stated reason.
ILLUSTRATIVE EXAMPLE · TEACHER BURNOUT MEASUREMENT RESEARCH · UNITED STATES
A school psychology team tested a three-factor model of teacher burnout and its relation to intention to leave the profession, using a questionnaire completed by teachers across one state.
The measurement model was specified from the published instrument before any estimation. The first fit was mediocre, and the modification indices pointed to correlated errors among many item pairs. Only the pairs whose items shared nearly identical wording were considered, each was justified in writing, and the others were left alone, since correlating them would have improved fit without a measurement reason. The indirect effects of the structural model were then bootstrapped, and the model file, the diagram and a log of each change were kept for the team.
Outcome: The team received the standardized loadings, the fit indices with the RMSEA interval, the structural paths with bootstrapped 95% confidence intervals, the AMOS model files and the revision log.
This example does not describe a real client or project. We never share details of actual client work, in line with the confidentiality we promise every researcher. This illustrative example is included to show the type, scope, and standard of work involved in this kind of analysis.
RESEARCH DISCIPLINES
Research Fields Where AMOS Is Common
AMOS is often used in psychology, education, business and the social sciences for scale validation and path models, and the same fit-chasing questions arise wherever latent constructs are modeled.
HOW WE ASSESS YOUR PROJECT
We Review Your Actual Research
Your assessment is based on a review of your actual research materials and analytical requirements, not a generic project category.
You Submit Your Project Details
Share whatever is available at the current stage, such as the research aim, protocol or proposal, dataset, variable list, manuscript or statistical requirements.
We Review Your Research and Define the Scope
Your statistically trained Research Coordinator reviews the materials to understand the study design, research questions, data structure, analytical requirements and expected deliverables. If clarification is needed, additional documents or information can be requested before the assessment is finalized.
Your Analysis Is Completed and Delivered
Once the scope and fixed project fee are agreed, the in-house statistician completes the work and the Research Coordinator remains the communication point through delivery, with the analysis, deliverables and timeline as agreed.
RESEARCHER VOICE
What Researchers Say
Feedback from a psychology researcher on poor model fit, the pull of modification indices and a workflow rebuilt from the files already in hand.
“Our issue with AMOS was not the interface itself; it was poor model fit and the temptation to follow modification indices without a theoretical reason. They worked directly with the files we already had and left us with a much cleaner, reproducible workflow rather than just screenshots of output.”
Statistical Support Within Your Research OnlineSPSS provides the agreed methodological, analytical and statistical reporting support, including the AMOS files described in the scope. The researcher or research team retains the scientific question, substantive interpretation, conclusions and overall responsibility for the research.
FREQUENTLY ASKED QUESTIONS
Questions About AMOS Analysis for Research
Short answers to what researchers ask before sharing an AMOS project, from the models we estimate and poor fit to model files, missing data, confidentiality and the assessment.
Can my questionnaire model be tested in AMOS?
Yes, where the items can reasonably be treated as continuous: an AMOS statistician at OnlineSPSS estimates confirmatory factor, path and structural equation models, with mediation, multigroup comparisons and latent growth where the design calls for them. The choice follows your theory and your indicators, and it is confirmed during the assessment.
My model fits poorly. Will you add modification indices until it fits?
No. A modification is made only when a measurement or substantive reason supports it, and each one is documented. If the fit stays poor, that is reported with the likely reasons, because an adjusted model fitted to one sample may not hold in the next.
Is a screenshot of my AMOS diagram enough to check the model?
No. A screenshot hides constraints, parameter labels and estimation settings, so the model file (.amw) and the data are read as they are. The same files are what Independent Statistical Review works from when a completed model only needs checking.
My data have missing values. Can AMOS still bootstrap my indirect effects?
Not in the same run. When AMOS fits a model to incomplete data by full-information maximum likelihood, it no longer offers bootstrapping, modification indices or normality tests, so the options are weighed in the assessment: multiple imputation before bootstrapping, complete-case analysis where it is defensible, a Bayesian estimate of the indirect effect within AMOS, or a platform such as Mplus or R that allows both in one model.
How do you protect my research data and confidentiality?
Your datasets and AMOS model files are handled confidentially, and project information is not published. An NDA is available where required and can be arranged before sensitive materials are shared. Read more about confidentiality and data security.
What happens when I request an assessment, and how long does it take?
You share your research question, design and relevant materials, such as the dataset and any existing model files, and a statistically trained Research Coordinator reviews the request and responds the same day. The analysis, deliverables, timeline and one fixed project fee are then confirmed before any work begins.
Still have a question? Find more answers in our full FAQ.
NEXT STEP
Discuss Your
AMOS Analysis With Us
Send the research question, the theory behind the model, the data and any AMOS file you have. We confirm identification and the estimation setup before any work begins.
No Commitment Required
Strictly Confidential
Fixed Project Fee
In-House PhD-Level Statisticians
Same-Day Response
Serving Researchers Since 2014