ALS Implicit

This page analyzes the hyperparameter tuning results for the implicit-feedback ALS matrix factorization model.

Parameter Search Space

/home/mde48/lenskit/lenskit-codex/.venv/lib/python3.12/site-packages/ray/tune/search/sample.py:700: RayDeprecationWarning: The `base` argument is deprecated. Please remove it as it is not actually needed in this method.
Parameter Type Distribution Values Selected
embedding_size Integer LogUniform 4 ≤ \(x\) ≤ 512 126
regularization.user Float LogUniform 1e-05 ≤ \(x\) ≤ 1 0.0389
regularization.item Float LogUniform 1e-05 ≤ \(x\) ≤ 1 0.146
damping.user Float LogUniform 1e-12 ≤ \(x\) ≤ 100 0.00633
damping.item Float LogUniform 1e-12 ≤ \(x\) ≤ 100 1.06e-11
weight Float Uniform 5 ≤ \(x\) ≤ 100 5.1

Final Result

Searching selected the following configuration:

{
    'embedding_size': 126,
    'regularization': {'user': 0.03891152508699394, 'item': 0.14615168345073604},
    'damping': {'user': 0.006328080127355385, 'item': 1.0570018436811442e-11},
    'weight': 5.099171622868312,
    'epochs': 7
}

With these metrics:

{
    'RBP': 0.17452988489343807,
    'DCG': 11.273938090623373,
    'NDCG': 0.41592125782256695,
    'RecipRank': 0.33620098456541636,
    'Hit10': 0.5872455902306648,
    'max_epochs': 30,
    'epoch_train_s': 10.926464226002281,
    'epoch_measure_s': 87.06303000600019,
    'done': True,
    'training_iteration': 7,
    'trial_id': '8dde8b04',
    'date': '2025-07-29_04-21-22',
    'timestamp': 1753777282,
    'time_this_iter_s': 97.99300146102905,
    'time_total_s': 810.4481289386749,
    'pid': 273041,
    'hostname': 'CCI-ws21',
    'node_ip': '10.248.127.152',
    'config': {
        'embedding_size': 126,
        'regularization': {'user': 0.03891152508699394, 'item': 0.14615168345073604},
        'damping': {'user': 0.006328080127355385, 'item': 1.0570018436811442e-11},
        'weight': 5.099171622868312,
        'epochs': 7
    },
    'time_since_restore': 810.4481289386749,
    'iterations_since_restore': 7
}

Parameter Analysis

Embedding Size

The embedding size is the hyperparameter that most affects the model’s fundamental logic, so let’s look at performance as a fufnction of it:

Learning Parameters

Iteration Completion

How many iterations, on average, did we complete?

How did the metric progress in the best result?

How did the metric progress in the longest results?