# Model Selection
Model selection is an integral part of portfolio construction and therefore appears in
most examples.
Tutorials using [`WalkForward`](https://skfolio.org/generated/skfolio.model_selection.WalkForward.html.md#skfolio.model_selection.WalkForward):
: * [Custom Pre-selection Using Volumes](https://skfolio.org/auto_examples/pre_selection/plot_3_custom_pre_selection_volumes.html.md#sphx-glr-auto-examples-pre-selection-plot-3-custom-pre-selection-volumes-py)
* [HRP vs HERC](https://skfolio.org/auto_examples/clustering/plot_3_hrp_vs_herc.html.md#sphx-glr-auto-examples-clustering-plot-3-hrp-vs-herc-py)
* [L1 and L2 Regularization](https://skfolio.org/auto_examples/mean_risk/plot_8_regularization.html.md#sphx-glr-auto-examples-mean-risk-plot-8-regularization-py)
* [NCO - Combinatorial Purged CV](https://skfolio.org/auto_examples/clustering/plot_5_nco_grid_search.html.md#sphx-glr-auto-examples-clustering-plot-5-nco-grid-search-py)
* [Stacking Optimization](https://skfolio.org/auto_examples/ensemble/plot_1_stacking.html.md#sphx-glr-auto-examples-ensemble-plot-1-stacking-py)
Tutorials using [`CombinatorialPurgedCV`](https://skfolio.org/generated/skfolio.model_selection.CombinatorialPurgedCV.html.md#skfolio.model_selection.CombinatorialPurgedCV):
: * [Drop Highly Correlated Assets](https://skfolio.org/auto_examples/pre_selection/plot_1_drop_correlated.html.md#sphx-glr-auto-examples-pre-selection-plot-1-drop-correlated-py)
* [HRP vs HERC](https://skfolio.org/auto_examples/clustering/plot_3_hrp_vs_herc.html.md#sphx-glr-auto-examples-clustering-plot-3-hrp-vs-herc-py)
* [NCO - Combinatorial Purged CV](https://skfolio.org/auto_examples/clustering/plot_5_nco_grid_search.html.md#sphx-glr-auto-examples-clustering-plot-5-nco-grid-search-py)
Below are dedicated Model Selection tutorials.