Regression analysis with full diagnostics Build, examine, and refine regression models — from simple linear fits to full factorial designs with categorical predictors, interactions, and logistic regression.

Analyse-it has helped tremendously. Previously I used Prism and Microsoft Excel, but Analyse-it has made my life so much easier and saved so much time.
Man Khun Chan, M.Sc., ART
Test Development Medical Technologist
The Hospital For Sick Children
Toronto, Canada

Fit simple and curve regression models

Fit the relationship between two variables using the model that best describes the data — linear, polynomial up to 6th order, logarithmic, exponential, power, or probit. Transform variables, test for lack of fit, and visualise the result with a scatter plot, fit line, and confidence bands.

Build complex models with multiple predictors

Combine continuous and categorical predictors in a single model — with simple, crossed, polynomial, and factorial terms. Categorical variables are coded as dummy variables automatically. Build full factorial, ANOVA, and ANCOVA models with adjusted effect means and five multiple comparison procedures including Tukey-Kramer, Dunnett, and Scheffé.

Model binary outcomes with logistic regression

Fit binary logistic or probit regression models with continuous variables, categorical factors, and interactions. Get parameter estimates, odds ratios with confidence intervals, Wald and likelihood-ratio tests, AIC/BIC, and the same leverage plots and influence diagnostics as linear regression.

Refine the model interactively

Add or remove terms, change the model structure, and click Recalculate. The results update immediately in the same workbook — fit statistics, diagnostic plots, hypothesis tests, all of it. No re-importing data, no starting a new analysis from scratch. Build the model incrementally until you're satisfied with the fit.

Assess each predictor's contribution

Use sequential (Type I) and partial (Type III) hypothesis tests to understand what each term adds to the model. Leverage plots show each predictor's effect after accounting for all others. VIF flags multicollinearity. Standardised betas let you compare predictor importance on a common scale.

Diagnose model fit

Check whether the model assumptions hold before you act on the results. Raw and standardised residual plots, sequence and lag plots, and residual distribution plots reveal structural problems. The Outliers & Influence plot using Cook's D and Studentised Residuals shows whether individual observations are driving the model.

Save computed variables and predict

Save fitted values, residuals, standardised residuals, studentised residuals, leverage, and Cook's D back to the dataset for further analysis. Predict new observations directly from the fitted model — with confidence intervals for the mean response and prediction intervals for individual observations.

Example analyses

See regression results in detail — parameter estimates, diagnostic plots, and interpretation — using real datasets you can download and follow along with.

TV Advertising Yields dataset
Shows power fit, with parameter estimates, residual plot and histogram, residual normality plot and test, and outlier/leverage/influence plot to identify observations exerting the most influence on the model.
Pulse rates before & after exercise
Multiple regression with continuous and categorical variables. Shows partial residual vs leverage plots for each term, effect of terms hypothesis tests, with residual and outlier/leverage/influence plot to identify extreme observations.
ICU admissions
Shows logistic regression with continuous and categorical variables on various patient attributes. Show effect of model and effect of terms with odds-ratios.

Validated, reliable, trusted for over 30-years

NIST-validated calculations Every statistic tested against NIST Standard Reference Datasets, published datasets and thousands of internal test-caes. No reliance on Excel's shaky built-in functions. See how we develop and validate Analyse-it →
Data stays on your PC No cloud processing, no uploads, no third-party access. It never leaves your computer — essential when working with sensitive, confidential, or patient-identifiable data.
Standard Excel workbooks Analyses are ordinary Excel workbooks that you can share with colleagues, archive for audit, and open on any machine with Excel — no Analyse-it license required.
No formulas to break Results contain no formulas, so they can't be accidentally edited or corrupted. The results you reported will be exactly what you find when you reopen the workbook.

Part of the Standard edition

Regression is one part of a complete statistical analysis toolkit. The Standard edition also includes ANOVA and ANCOVA, PCA and factor analysis, logistic regression, descriptive statistics, hypothesis testing, and correlation. See everything in the Standard edition →

Technical details

Simple regression

  • Linear, polynomial (2nd–6th order), logarithmic, exponential, power, probit
  • X and Y variable transformations
  • F-test for lack of fit

Multiple regression

  • Continuous and categorical predictors
  • Simple, crossed, polynomial, factorial terms
  • Automatic dummy variable coding
  • Full factorial models
  • ANOVA, ANCOVA

Logistic regression

  • Logit and probit link functions
  • Continuous, categorical, polynomial, and interaction terms
  • Automatic dummy variable coding
  • Odds ratio estimates with confidence intervals

Fit statistics

  • Parameter estimates with confidence intervals and standard errors
  • R², adjusted R², AIC, BIC
  • VIF for multicollinearity
  • Standardised betas
  • Model equation
  • Correlation/covariance of estimates matrices
  • Odds ratios with confidence intervals (logistic)
  • Log-likelihood, deviance (logistic)

Hypothesis tests

  • Sequential (Type I SS) for each term
  • Partial (Type III SS) for each term
  • F-test for overall model
  • Wald and likelihood-ratio tests (logistic)

Effect means & multiple comparisons

  • Adjusted means with confidence intervals
  • Main effect and interaction plots
  • Tukey-Kramer, Dunnett, Hsu, Scheffé, Student’s t

Diagnostic plots

  • Scatter with fit line and confidence/prediction bands
  • Raw and standardised residual plots
  • Sequence and lag plots
  • Residual distribution plot
  • Outliers & Influence plot (Cook's D, Studentised Residuals)
  • Leverage (partial residual) plots

Computed variables

  • Fitted Y
  • Residuals, standardised residuals, studentised residuals
  • Leverage
  • Cook's D

Prediction

  • Predict Y for new X values
  • Mean response with confidence interval
  • Individual response with prediction interval