Decision tree software · Mac & Windows

A decision tree tool you can explain, not just score.

Walk someone through the model, not just the score. The tree is drawn rather than described, variable importance is ranked so you can say which fields carried it, and pruning is cost-complexity with k-fold cross-validation. Native on Mac and Windows, bought once. Free to try on your own data before you decide.

Both
Classification & regression
~5M
Rows, smoothly
Once
One payment, not annual
2
Platforms, equally native
A regression tree in Stratum with one leaf selected, above the data grid showing exactly those rows highlighted: the path from the root is lit, each ancestor carries a band showing the share of its rows that are selected, and the highlighting in the grid stops precisely at the split value
A leaf, and the rows inside it. Select one leaf and the data grid highlights exactly those rows, with the path from the root lit the whole way up.
An out-of-bag error curve falling as trees are added to a random forest, beside the out-of-bag confusion matrix for the three penguin species
Accuracy without a holdout. Every tree leaves about a third of the rows out of its bootstrap sample, so the forest scores itself on data it never saw — 95.93% accurate across all 344 rows, with the per-class breakdown beside it. Nothing was held back to measure it.
A partial-dependence plot in Stratum showing the fitted effect of carat on predicted price with the other predictors averaged out, beside a panel giving the forest's tree count, features per split and out-of-bag error
What the ensemble learned. The fitted effect of one predictor with the others averaged out — steep to about two carats, where 96% of the stones sit. Out-of-bag R² 0.978, scored on all 53,940 rows without holding any back.
A fitted decision tree with split criteria and leaf statistics
The tree, drawn. Split criteria at every node and the statistics at every leaf — readable without re-deriving it.
Variable importance ranking from the decision tree
What actually drove it. Importance ranked, so the model is something you can explain rather than only score.

Trees in Stratum

A subscription doesn’t end. A one-time purchase does.

Subscription analytics tools

Most data-mining and analytics suites are sold as an annual subscription — often quoted only after a sales call. Whatever the number turns out to be, it returns every year, and access stops when you stop paying.

Yr 1Pay Yr 2Pay Yr 3Pay Yr 4Pay Yr 5Pay

Five years, five bills — and no software left if you stop.

Stratum

Bought once. The version you buy keeps working forever, online or off, on Mac and Windows alike.

Yr 2— Yr 3— Yr 4— Yr 5—

$249 for Professional — once, and it’s yours.

CapabilityIn Stratum
Classification treesCategorical outcomes, with split criteria and class counts at the leaves
Regression treesNumeric outcomes, with predicted value and node size at the leaves
Split criteriaGini or entropy for classification, variance reduction for regression
Growth controlMaximum depth, minimum node size, minimum improvement, maximum branches per split
PruningCost-complexity pruning chosen by k-fold cross-validation, at the minimum-error tree or the one-standard-error tree
Variable importanceRanked across the fitted model, and across the ensemble
Random forestsTree count, predictors per split (mtry), sample fraction and seed, with out-of-bag error, an OOB error curve and an OOB confusion matrix
Boosted treesLearning rate, subsample fraction and tree depth, with training and validation curves and early stopping
Reading the ensemblePartial-dependence plots per predictor, so a forest is not left as a black box
Classifier diagnosticsConfusion matrix, misclassification rate and test AUC on held-out rows
Held-out validationSeeded training / validation / test splits, optionally stratified, with model comparison on the same partition
Linked selectionClick a node in the diagram to select the rows that reach it — in the datasheet and in every other chart
Tree diagramDrawn, zoomable, exportable to PNG or PDF at print resolution
Numerical validationPublished validation record — the outside tool named for every statistic, including the gaps
PricingOne-time (Professional $249) — no subscription
Where your decision-tree analyses live in Stratum — menu path by menu path
Predict a category

Classification Tree — a tree for a categorical outcome, with the split criterion named at every node rather than hidden in the fit.

Predict a number

Regression Tree — the same method for a numeric response, with the predicted value and group size at each leaf.

Control how far it grows

Depth & node size — maximum depth, minimum node size, minimum improvement and branches per split, so the tree is as simple as you can defend.

Prune it without guessing where

Cross-validated pruning — cost-complexity pruning with k-fold cross-validation, stopping either at the minimum-error tree or at the one-standard-error tree, which is the smaller tree statistically indistinguishable from it.

Which variables carried the model

Variable importance — ranked, so you get a model you can explain to someone who did not fit it.

Accuracy over interpretability

Random Forest — an ensemble of trees when a single tree is too unstable to trust, with out-of-bag error, an OOB error curve and an OOB confusion matrix, so accuracy is measured without giving up any rows.

Squeeze out more accuracy

Boosted Trees — gradient boosting with learning rate, subsample fraction and depth in your hands, and early stopping read off the validation curve rather than guessed.

Explain what the ensemble learned

Partial Dependence — the fitted effect of one predictor with the others averaged out, plotted, which is how a forest stops being a black box.

Compare the candidates honestly

Model Comparison — a tree, a forest and a boosted model scored on the same held-out rows, with confusion matrices and test AUC side by side.

The tree as a picture

Tree diagram — drawn, zoomable and exportable at print resolution, not a nested text dump you have to read sideways.

The statistics around the model

Regression, ANOVA, PCA — the rest of the toolkit in the same app, so a tree is not a silo.

Point-and-click throughout — and equally native on a Mac, where most data-mining tools are Windows-first.

Drawn, and explainable. Classification and regression trees come out as a diagram you can read and export, with the split criterion named at every node and variable importance ranked underneath — and random forests and boosted trees alongside for when accuracy matters more than the picture. One-time price, equally native on a Mac.

What you get alongside it

Decision trees are in Stratum’s Professional edition together with PCA, MANOVA, correspondence analysis, clustering and SPC — on top of everything in Standard, including descriptive statistics, ANOVA, correlation and contingency, and linear and multiple regression with full diagnostics. Import your .csv, .xlsx or .sav and try it on your own data first.

Frequently asked questions

Does Stratum fit classification and regression trees?

Yes — classification trees for categorical outcomes and regression trees for numeric ones, with the split criterion, maximum depth and minimum node size under your control.

Can I see which variables mattered?

Yes — variable importance is ranked for the fitted model. Decision trees explained walks through reading one.

Does it do random forests?

Yes — random forests and boosted trees are included in the same edition, so you can compare a single explainable tree against an ensemble on the same data.

Can I export the tree diagram?

Yes — the tree is drawn rather than printed as text, and exports to PNG or PDF at print resolution.

Does Stratum run on Mac?

Yes — Stratum is a native app for both macOS 14+ and Windows 10/11, so trees work the same on either.

Is it a subscription?

No — Stratum is a one-time purchase. Trees are in Professional ($249), and you can upgrade from Standard later.