ValidMind for validation 2 — Start the validation process

Learn how to use ValidMind for your end-to-end validation process with our series of four introductory notebooks. In this second notebook, independently verify the data quality tests performed on the dataset used to train the champion.

You'll learn how to run relevant validation tests with ValidMind, log the results of those tests to the ValidMind Platform, and insert your logged test results as evidence into your validation report. You'll become familiar with the tests available in ValidMind, as well as how to run them. Running tests during validation is crucial to the effective challenge process, as we want to independently evaluate the evidence and assessments provided by the development team.

While running our tests in this notebook, we'll focus on:

For a full list of out-of-the-box tests and descriptions, use the interactive ValidMind test sandbox.

Learn by doing

Our course tailor-made for validators new to ValidMind combines this series of notebooks with more a more in-depth introduction to the ValidMind Platform — Validator Fundamentals

Prerequisites

In order to independently assess the quality of your datasets with notebook, you'll need to first have:

Need help with the above steps?

Refer to the first notebook in this series: 1 — Set up the ValidMind Library for validation

Setting up

Initialize the ValidMind Library

First, let's connect up the ValidMind Library to our model we previously registered in the ValidMind Platform:

  1. On the left sidebar that appears for your model, select Getting Started and select Validation from the Document drop-down menu.

  2. Click Copy snippet to clipboard.

  3. Next, load your model identifier credentials from an .env file or replace the placeholder with your own code snippet:

# Make sure the ValidMind Library is installed

%pip install -q validmind

# Load your model identifier credentials from an `.env` file

%load_ext dotenv
%dotenv .env

# Or replace with your code snippet

import validmind as vm

vm.init(
    # api_host="...",
    # api_key="...",
    # api_secret="...",
    # model="...",
    document="validation-report",
)
Note: you may need to restart the kernel to use updated packages.
2026-07-31 16:46:07,859 - INFO(validmind.api_client): 🎉 Connected to ValidMind!
📊 Model: [ValidMind Academy] Model validation (ID: cmalguc9y02ok199q2db381ib)
📁 Document Type: validation_report

Load the sample dataset

Let's first import the public Bank Customer Churn Prediction dataset from Kaggle, which was used to develop the dummy champion.

We'll use this dataset to review steps that should have been conducted during the initial development and documentation of the champion to ensure that the model was built correctly. By independently performing steps taken by the development team, we can confirm whether the model was built using appropriate and properly processed data.

In our below example, note that:

  • The target column, Exited has a value of 1 when a customer has churned and 0 otherwise.
  • The ValidMind Library provides a wrapper to automatically load the dataset as a Pandas DataFrame object. A Pandas Dataframe is a two-dimensional tabular data structure that makes use of rows and columns.
from validmind.datasets.classification import customer_churn as demo_dataset

print(
    f"Loaded demo dataset with: \n\n\t• Target column: '{demo_dataset.target_column}' \n\t• Class labels: {demo_dataset.class_labels}"
)

raw_df = demo_dataset.load_data()
raw_df.head()
Loaded demo dataset with: 

    • Target column: 'Exited' 
    • Class labels: {'0': 'Did not exit', '1': 'Exited'}
CreditScore Geography Gender Age Tenure Balance NumOfProducts HasCrCard IsActiveMember EstimatedSalary Exited
0 619 France Female 42 2 0.00 1 1 1 101348.88 1
1 608 Spain Female 41 1 83807.86 1 0 1 112542.58 0
2 502 France Female 42 8 159660.80 3 1 0 113931.57 1
3 699 France Female 39 1 0.00 2 0 0 93826.63 0
4 850 Spain Female 43 2 125510.82 1 1 1 79084.10 0

Verifying data quality adjustments

Let's say that thanks to the documentation submitted by the development team (Learn more: ValidMind for development), we know that the sample dataset was first modified before being used to train the champion. After performing some data quality assessments on the raw dataset, it was determined that the dataset required rebalancing, and highly correlated features were also removed.

Identify qualitative tests

During validation, we use the same data processing logic and training procedure to confirm that the model's results can be reproduced independently, so let's start by doing some data quality assessments by running a few individual tests just like the development team did.

Use the vm.tests.list_tests() function introduced by the first notebook in this series in combination with vm.tests.list_tags() and vm.tests.list_tasks() to find which prebuilt tests are relevant for data quality assessment:

  • tasks represent the kind of modeling task associated with a test. Here we'll focus on classification tasks.
  • tags are free-form descriptions providing more details about the test, for example, what category the test falls into. Here we'll focus on the data_quality tag.
# Get the list of available task types
sorted(vm.tests.list_tasks())
['classification',
 'clustering',
 'data_validation',
 'feature_extraction',
 'monitoring',
 'nlp',
 'regression',
 'residual_analysis',
 'text_classification',
 'text_generation',
 'text_qa',
 'text_summarization',
 'time_series_forecasting',
 'visualization']
# Get the list of available tags
sorted(vm.tests.list_tags())
['AUC',
 'analysis',
 'anomaly',
 'anomaly_detection',
 'bias_and_fairness',
 'binary_classification',
 'calibration',
 'categorical_data',
 'classification',
 'classification_metrics',
 'clustering',
 'correlation',
 'credit_risk',
 'data_analysis',
 'data_distribution',
 'data_quality',
 'data_validation',
 'descriptive_statistics',
 'dimensionality_reduction',
 'distribution',
 'embeddings',
 'feature_importance',
 'feature_selection',
 'few_shot',
 'forecasting',
 'frequency_analysis',
 'kmeans',
 'linear_regression',
 'llm',
 'logistic_regression',
 'metadata',
 'model_comparison',
 'model_diagnosis',
 'model_explainability',
 'model_interpretation',
 'model_performance',
 'model_predictions',
 'model_selection',
 'model_training',
 'model_validation',
 'multiclass_classification',
 'nlp',
 'normality',
 'numerical_data',
 'outlier',
 'outliers',
 'qualitative',
 'rag_performance',
 'ragas',
 'regression',
 'retrieval_performance',
 'scorecard',
 'seasonality',
 'senstivity_analysis',
 'sklearn',
 'stationarity',
 'statistical_test',
 'statistics',
 'statsmodels',
 'tabular_data',
 'text_data',
 'threshold_optimization',
 'time_series_data',
 'unit_root_test',
 'visualization',
 'zero_shot']

You can pass tags and tasks as parameters to the vm.tests.list_tests() function to filter the tests based on the tags and task types.

For example, to find tests related to tabular data quality for classification models, you can call list_tests() like this:

vm.tests.list_tests(task="classification", tags=["tabular_data", "data_quality"])
ID Name Description Has Figure Has Table Required Inputs Params Tags Tasks
validmind.data_validation.ClassImbalance Class Imbalance Evaluates and quantifies class distribution imbalance in a dataset used by a machine learning model.... True True ['dataset'] {'min_percent_threshold': {'type': 'int', 'default': 10}} ['tabular_data', 'binary_classification', 'multiclass_classification', 'data_quality'] ['classification']
validmind.data_validation.DescriptiveStatistics Descriptive Statistics Performs a detailed descriptive statistical analysis of both numerical and categorical data within a model's... False True ['dataset'] {} ['tabular_data', 'time_series_data', 'data_quality'] ['classification', 'regression']
validmind.data_validation.Duplicates Duplicates Tests dataset for duplicate entries, ensuring model reliability via data quality verification.... False True ['dataset'] {'min_threshold': {'type': '_empty', 'default': 1}} ['tabular_data', 'data_quality', 'text_data'] ['classification', 'regression']
validmind.data_validation.HighCardinality High Cardinality Assesses the number of unique values in categorical columns to detect high cardinality and potential overfitting.... False True ['dataset'] {'num_threshold': {'type': 'int', 'default': 100}, 'percent_threshold': {'type': 'float', 'default': 0.1}, 'threshold_type': {'type': 'str', 'default': 'percent'}} ['tabular_data', 'data_quality', 'categorical_data'] ['classification', 'regression']
validmind.data_validation.HighPearsonCorrelation High Pearson Correlation Identifies highly correlated feature pairs in a dataset suggesting feature redundancy or multicollinearity.... False True ['dataset'] {'max_threshold': {'type': 'float', 'default': 0.3}, 'top_n_correlations': {'type': 'int', 'default': 10}, 'feature_columns': {'type': 'list', 'default': None}} ['tabular_data', 'data_quality', 'correlation'] ['classification', 'regression']
validmind.data_validation.MissingValues Missing Values Evaluates dataset quality by ensuring missing value percentage across all features does not exceed a set threshold.... False True ['dataset'] {'min_percentage_threshold': {'type': 'float', 'default': 1.0}} ['tabular_data', 'data_quality'] ['classification', 'regression']
validmind.data_validation.MissingValuesBarPlot Missing Values Bar Plot Assesses the percentage and distribution of missing values in the dataset via a bar plot, with emphasis on... True False ['dataset'] {'threshold': {'type': 'int', 'default': 80}, 'fig_height': {'type': 'int', 'default': 600}} ['tabular_data', 'data_quality', 'visualization'] ['classification', 'regression']
validmind.data_validation.Skewness Skewness Evaluates the skewness of numerical data in a dataset to check against a defined threshold, aiming to ensure data... False True ['dataset'] {'max_threshold': {'type': '_empty', 'default': 1}} ['data_quality', 'tabular_data'] ['classification', 'regression']
validmind.plots.BoxPlot Box Plot Generates customizable box plots for numerical features in a dataset with optional grouping using Plotly.... True False ['dataset'] {'columns': {'type': 'Optional', 'default': None}, 'group_by': {'type': 'Optional', 'default': None}, 'width': {'type': 'int', 'default': 1800}, 'height': {'type': 'int', 'default': 1200}, 'colors': {'type': 'Optional', 'default': None}, 'show_outliers': {'type': 'bool', 'default': True}, 'title_prefix': {'type': 'str', 'default': 'Box Plot of'}} ['tabular_data', 'visualization', 'data_quality'] ['classification', 'regression', 'clustering']
validmind.plots.HistogramPlot Histogram Plot Generates customizable histogram plots for numerical features in a dataset using Plotly.... True False ['dataset'] {'columns': {'type': 'Optional', 'default': None}, 'bins': {'type': 'Union', 'default': 30}, 'color': {'type': 'str', 'default': 'steelblue'}, 'opacity': {'type': 'float', 'default': 0.7}, 'show_kde': {'type': 'bool', 'default': True}, 'normalize': {'type': 'bool', 'default': False}, 'log_scale': {'type': 'bool', 'default': False}, 'title_prefix': {'type': 'str', 'default': 'Histogram of'}, 'width': {'type': 'int', 'default': 1200}, 'height': {'type': 'int', 'default': 800}, 'n_cols': {'type': 'int', 'default': 2}, 'vertical_spacing': {'type': 'float', 'default': 0.15}, 'horizontal_spacing': {'type': 'float', 'default': 0.1}} ['tabular_data', 'visualization', 'data_quality'] ['classification', 'regression', 'clustering']
validmind.stats.DescriptiveStats Descriptive Stats Provides comprehensive descriptive statistics for numerical features in a dataset.... False True ['dataset'] {'columns': {'type': 'Optional', 'default': None}, 'include_advanced': {'type': 'bool', 'default': True}, 'confidence_level': {'type': 'float', 'default': 0.95}} ['tabular_data', 'statistics', 'data_quality'] ['classification', 'regression', 'clustering']
Want to learn more about navigating ValidMind tests?

Refer to our notebook outlining the utilities available for viewing and understanding available ValidMind tests: Explore tests

Initialize the ValidMind dataset

With the individual tests we want to run identified, the next step is to connect your data with a ValidMind Dataset object. This step is always necessary every time you want to connect a dataset to documentation and produce test results through ValidMind, but you only need to do it once per dataset.

Initialize a ValidMind dataset object using the init_dataset function from the ValidMind (vm) module. For this example, we'll pass in the following arguments:

  • dataset — The raw dataset that you want to provide as input to tests.
  • input_id — A unique identifier that allows tracking what inputs are used when running each individual test.
  • target_column — A required argument if tests require access to true values. This is the name of the target column in the dataset.
# vm_raw_dataset is now a VMDataset object that you can pass to any ValidMind test
vm_raw_dataset = vm.init_dataset(
    dataset=raw_df,
    input_id="raw_dataset",
    target_column="Exited",
)

Run data quality tests

Now that we know how to initialize a ValidMind dataset object, we're ready to run some tests!

You run individual tests by calling the run_test function provided by the validmind.tests module. For the examples below, we'll pass in the following arguments:

  • test_id — The ID of the test to run, as seen in the ID column when you run list_tests.
  • params — A dictionary of parameters for the test. These will override any default_params set in the test definition.

Run tabular data tests

The inputs expected by a test can also be found in the test definition — let's take validmind.data_validation.DescriptiveStatistics as an example.

Note that the output of the describe_test() function below shows that this test expects a dataset as input:

vm.tests.describe_test("validmind.data_validation.DescriptiveStatistics")
Test: Descriptive Statistics ('validmind.data_validation.DescriptiveStatistics')

Now, let's run a few tests to assess the quality of the dataset:

result2 = vm.tests.run_test(
    test_id="validmind.data_validation.ClassImbalance",
    inputs={"dataset": vm_raw_dataset},
    params={"min_percent_threshold": 30},
)

❌ Class Imbalance

The Class Imbalance test evaluates the distribution of target classes in the dataset by measuring the percentage share of each class and comparing those shares to a minimum threshold. For the Exited target, the results table and bar chart show two classes with materially different representation levels. Class 0 accounts for 79.80% of rows and class 1 accounts for 20.20% of rows, and each class is assessed against the configured minimum percentage threshold of 30%.

Key insights:

  • Target distribution is uneven: The Exited target is split 79.80% for class 0 and 20.20% for class 1, indicating a substantial difference in representation between the two classes.
  • Minority class fails threshold: Class 1 is below the configured 30% minimum percentage threshold and is marked Fail in the test output.
  • Majority class passes threshold: Class 0 exceeds the 30% threshold with 79.80% of rows and is marked Pass.

The results show that the target distribution is concentrated in class 0, while class 1 is represented at 20.20%. Under the configured 30% minimum threshold, the dataset passes for the majority class and fails for the minority class. Collectively, the table and chart indicate class imbalance in the Exited target under this test configuration.

Parameters:

{
  "min_percent_threshold": 30
}
            

Tables

Exited Class Imbalance

Exited Percentage of Rows (%) Pass/Fail
0 79.80% Pass
1 20.20% Fail

Figures

ValidMind Figure validmind.data_validation.ClassImbalance:c218

The output above shows that the validmind.data_validation.ClassImbalance test did not pass according to the value we set for min_percent_threshold — great, this matches what was reported by the development team.

To address this issue, we'll re-run the test on some processed data. In this case let's apply a very simple rebalancing technique to the dataset:

import pandas as pd

raw_copy_df = raw_df.sample(frac=1)  # Create a copy of the raw dataset

# Create a balanced dataset with the same number of exited and not exited customers
exited_df = raw_copy_df.loc[raw_copy_df["Exited"] == 1]
not_exited_df = raw_copy_df.loc[raw_copy_df["Exited"] == 0].sample(n=exited_df.shape[0])

balanced_raw_df = pd.concat([exited_df, not_exited_df])
balanced_raw_df = balanced_raw_df.sample(frac=1, random_state=42)

With this new balanced dataset, you can re-run the individual test to see if it now passes the class imbalance test requirement.

As this is technically a different dataset, remember to first initialize a new ValidMind Dataset object to pass in as input as required by run_test():

# Register new data and now 'balanced_raw_dataset' is the new dataset object of interest
vm_balanced_raw_dataset = vm.init_dataset(
    dataset=balanced_raw_df,
    input_id="balanced_raw_dataset",
    target_column="Exited",
)
# Pass the initialized `balanced_raw_dataset` as input into the test run
result = vm.tests.run_test(
    test_id="validmind.data_validation.ClassImbalance",
    inputs={"dataset": vm_balanced_raw_dataset},
    params={"min_percent_threshold": 30},
)

✅ Class Imbalance

The Class Imbalance test evaluates the distribution of target classes in the dataset by measuring the percentage share of each class and comparing those shares against a minimum threshold. In this result, the target variable Exited is shown across two classes, 0 and 1, with each class representing 50.00% of rows. The table also records a pass/fail outcome for each class using the configured minimum percentage threshold of 30%.

Key insights:

  • Equal class distribution observed: Both Exited = 0 and Exited = 1 account for 50.00% of the dataset, indicating an even split between the two target classes.
  • All classes exceed threshold: Each class is above the configured 30% minimum percentage threshold, and both classes receive a Pass result.
  • No minority class identified: The reported class shares are identical, so neither target class appears as underrepresented in this test output.

The results show a balanced binary target distribution for Exited, with both classes present at equal frequency. Relative to the configured 30% threshold, no class falls below the minimum required share, and the test records no failed class-level imbalance condition.

Parameters:

{
  "min_percent_threshold": 30
}
            

Tables

Exited Class Imbalance

Exited Percentage of Rows (%) Pass/Fail
0 50.00% Pass
1 50.00% Pass

Figures

ValidMind Figure validmind.data_validation.ClassImbalance:7d87

Remove highly correlated features

Next, let's also remove highly correlated features from our dataset as outlined by the development team. Removing highly correlated features helps make the model simpler, more stable, and easier to understand.

You can utilize the output from a ValidMind test for further use — in this below example, to retrieve the list of features with the highest correlation coefficients and use them to reduce the final list of features for modeling.

First, we'll run validmind.data_validation.HighPearsonCorrelation with the balanced_raw_dataset we initialized previously as input as is for comparison with later runs:

corr_result = vm.tests.run_test(
    test_id="validmind.data_validation.HighPearsonCorrelation",
    params={"max_threshold": 0.3},
    inputs={"dataset": vm_balanced_raw_dataset},
)

❌ High Pearson Correlation

The High Pearson Correlation test evaluates pairwise linear relationships among features to identify highly correlated variable pairs that may indicate redundancy or multicollinearity. The result table reports the top correlations ranked by absolute Pearson coefficient together with a pass/fail assessment using a threshold of 0.3. Across the 10 reported pairs, coefficients range from -0.1856 to 0.3416, and only one pair exceeds the threshold. The highest reported correlation is between Age and Exited at 0.3416, while all remaining reported relationships are below the threshold and marked as passing.

Key insights:

  • One pair exceeds threshold: Age and Exited records a Pearson correlation of 0.3416 and is the only reported pair classified as Fail under the 0.3 threshold.
  • Remaining reported pairs are below threshold: The other 9 reported correlations are all marked Pass, with absolute coefficients ranging from 0.0299 to 0.1856.
  • Observed non-failing relationships are weak: Among the passing pairs, the largest absolute correlations are Balance with NumOfProducts at -0.1856 and IsActiveMember with Exited at -0.1733, both materially below the threshold.
  • Reported correlations are concentrated near zero: Several reported pairs have coefficients with small magnitudes, including CreditScore with Exited at -0.0361, Age with NumOfProducts at -0.0415, and HasCrCard with IsActiveMember at -0.0299.

The reported correlation structure shows a single feature pair above the configured threshold and a broader set of pairwise relationships with comparatively small magnitudes. The most pronounced observed relationship is the positive correlation between Age and Exited, while the remaining listed pairs do not cross the test limit. Overall, the reported results indicate limited evidence of elevated pairwise linear dependence within the top correlations returned by the test.

Parameters:

{
  "max_threshold": 0.3
}
            

Tables

Columns Coefficient Pass/Fail
(Age, Exited) 0.3416 Fail
(Balance, NumOfProducts) -0.1856 Pass
(IsActiveMember, Exited) -0.1733 Pass
(Balance, Exited) 0.1336 Pass
(NumOfProducts, IsActiveMember) 0.0583 Pass
(NumOfProducts, Exited) -0.0572 Pass
(CreditScore, IsActiveMember) 0.0431 Pass
(Age, NumOfProducts) -0.0415 Pass
(CreditScore, Exited) -0.0361 Pass
(HasCrCard, IsActiveMember) -0.0299 Pass

The output above shows that the test did not pass according to the value we set for max_threshold — as reported and expected.

corr_result is an object of type TestResult. We can inspect the result object to see what the test has produced:

print(type(corr_result))
print("Result ID: ", corr_result.result_id)
print("Params: ", corr_result.params)
print("Passed: ", corr_result.passed)
print("Tables: ", corr_result.tables)
<class 'validmind.vm_models.result.result.TestResult'>
Result ID:  validmind.data_validation.HighPearsonCorrelation
Params:  {'max_threshold': 0.3}
Passed:  False
Tables:  [ResultTable]

Let's remove the highly correlated features and create a new VM dataset object.

We'll begin by checking out the table in the result and extracting a list of features that failed the test:

# Extract table from `corr_result.tables`
features_df = corr_result.tables[0].data
features_df
Columns Coefficient Pass/Fail
0 (Age, Exited) 0.3416 Fail
1 (Balance, NumOfProducts) -0.1856 Pass
2 (IsActiveMember, Exited) -0.1733 Pass
3 (Balance, Exited) 0.1336 Pass
4 (NumOfProducts, IsActiveMember) 0.0583 Pass
5 (NumOfProducts, Exited) -0.0572 Pass
6 (CreditScore, IsActiveMember) 0.0431 Pass
7 (Age, NumOfProducts) -0.0415 Pass
8 (CreditScore, Exited) -0.0361 Pass
9 (HasCrCard, IsActiveMember) -0.0299 Pass
# Extract list of features that failed the test
high_correlation_features = features_df[features_df["Pass/Fail"] == "Fail"]["Columns"].tolist()
high_correlation_features
['(Age, Exited)']

Next, extract the feature names from the list of strings (example: (Age, Exited) > Age):

high_correlation_features = [feature.split(",")[0].strip("()") for feature in high_correlation_features]
high_correlation_features
['Age']

Now, it's time to re-initialize the dataset with the highly correlated features removed.

Note the use of a different input_id. This allows tracking the inputs used when running each individual test.

# Remove the highly correlated features from the dataset
balanced_raw_no_age_df = balanced_raw_df.drop(columns=high_correlation_features)

# Re-initialize the dataset object
vm_raw_dataset_preprocessed = vm.init_dataset(
    dataset=balanced_raw_no_age_df,
    input_id="raw_dataset_preprocessed",
    target_column="Exited",
)

Re-running the test with the reduced feature set should pass the test:

corr_result = vm.tests.run_test(
    test_id="validmind.data_validation.HighPearsonCorrelation",
    params={"max_threshold": 0.3},
    inputs={"dataset": vm_raw_dataset_preprocessed},
)

✅ High Pearson Correlation

The High Pearson Correlation test evaluates pairwise linear relationships among features to identify potentially redundant variables or multicollinearity. The result table lists the top reported feature pairs with their Pearson correlation coefficients and pass/fail status using a maximum threshold of 0.3. Across the reported pairs, coefficients range from -0.1856 to 0.1336, and all entries are marked as Pass. The table includes both positive and negative relationships, with the largest absolute coefficient observed for the Balance and NumOfProducts pair.

Key insights:

  • No threshold breaches observed: All reported feature pairs pass the test against the 0.3 threshold, with no absolute correlation coefficient exceeding the configured limit.
  • Largest relationship remains modest: The strongest reported relationship is between Balance and NumOfProducts at -0.1856, which remains below the threshold by a clear margin.
  • Observed correlations are weak overall: Reported coefficients are concentrated near zero, including values such as -0.1733 for IsActiveMember and Exited, 0.1336 for Balance and Exited, and 0.0583 for NumOfProducts and IsActiveMember.
  • Both positive and negative associations appear: The reported pairs show a mix of directions, with negative coefficients more common among the largest-magnitude relationships in the table.

The reported correlation structure indicates limited linear dependence among the top feature pairs returned by the test. No pair in the displayed results exceeds the configured correlation threshold, and the largest absolute relationships remain modest in magnitude. Taken together, the output shows that the strongest observed pairwise linear associations in this result set are weak relative to the test criterion.

Parameters:

{
  "max_threshold": 0.3
}
            

Tables

Columns Coefficient Pass/Fail
(Balance, NumOfProducts) -0.1856 Pass
(IsActiveMember, Exited) -0.1733 Pass
(Balance, Exited) 0.1336 Pass
(NumOfProducts, IsActiveMember) 0.0583 Pass
(NumOfProducts, Exited) -0.0572 Pass
(CreditScore, IsActiveMember) 0.0431 Pass
(CreditScore, Exited) -0.0361 Pass
(HasCrCard, IsActiveMember) -0.0299 Pass
(Balance, HasCrCard) -0.0248 Pass
(Tenure, IsActiveMember) -0.0223 Pass

You can also plot the correlation matrix to visualize the new correlation between features:

corr_result = vm.tests.run_test(
    test_id="validmind.data_validation.PearsonCorrelationMatrix",
    inputs={"dataset": vm_raw_dataset_preprocessed},
)

Pearson Correlation Matrix

The PearsonCorrelationMatrix test evaluates linear dependency among numerical variables using pairwise Pearson correlation coefficients. The result is presented as a symmetric heat map covering CreditScore, Tenure, Balance, NumOfProducts, HasCrCard, IsActiveMember, EstimatedSalary, and Exited, with coefficients ranging from -1 to 1 and diagonal values of 1.0. Off-diagonal correlations in this matrix are generally small in magnitude, and the plotted values identify the relative strength and direction of each pairwise linear relationship.

Key insights:

  • No high pairwise correlations observed: All off-diagonal correlation coefficients shown in the heat map are well below the 0.7 absolute-value threshold highlighted by the test methodology. The largest observed absolute correlation is 0.19.

  • Strongest relationship is still weak: The highest absolute pairwise correlation appears between Balance and NumOfProducts at -0.19. This indicates only a weak negative linear relationship between these two variables.

  • Exited has limited linear association: Correlations between Exited and the other variables remain low, ranging from -0.17 with IsActiveMember to 0.13 with Balance. Additional Exited correlations include -0.06 with NumOfProducts, -0.04 with CreditScore, -0.02 with Tenure, -0.02 with HasCrCard, and 0.00 with EstimatedSalary.

  • Most feature relationships cluster near zero: Many variable pairs show coefficients between approximately -0.03 and 0.06, including EstimatedSalary with most other variables, HasCrCard with all other displayed features, and Tenure with the remaining variables. This reflects minimal linear dependency across most of the numerical inputs.

The correlation structure shows uniformly low pairwise linear dependence across the variables included in the test. No feature pair exhibits a strong positive or negative linear relationship, and the largest observed associations remain weak in magnitude. The results therefore indicate limited redundancy from linear correlation within the numerical feature set represented in the heat map.

Figures

ValidMind Figure validmind.data_validation.PearsonCorrelationMatrix:57a9

Documenting test results

Now that we've done some analysis on two different datasets, we can use ValidMind to easily document why certain things were done to our raw data with testing to support it. Every test result returned by the run_test() function has a .log() method that can be used to send the test results to the ValidMind Platform.

When logging validation test results to the platform, you'll need to manually add those results to the desired section of the validation report. To demonstrate how to add test results to your validation report, we'll log our data quality tests and insert the results via the ValidMind Platform.

Configure and run comparison tests

Below, we'll perform comparison tests between the original raw dataset (raw_dataset) and the final preprocessed (raw_dataset_preprocessed) dataset, again logging the results to the ValidMind Platform.

We can specify all the tests we'd ike to run in a dictionary called test_config, and we'll pass in the following arguments for each test:

  • params: Individual test parameters.
  • input_grid: Individual test inputs to compare. In this case, we'll input our two datasets for comparison.

Note here that the input_grid expects the input_id of the dataset as the value rather than the variable name we specified:

# Individual test config with inputs specified
test_config = {
    "validmind.data_validation.ClassImbalance": {
        "input_grid": {"dataset": ["raw_dataset", "raw_dataset_preprocessed"]},
        "params": {"min_percent_threshold": 30}
    },
    "validmind.data_validation.HighPearsonCorrelation": {
        "input_grid": {"dataset": ["raw_dataset", "raw_dataset_preprocessed"]},
        "params": {"max_threshold": 0.3}
    },
}

Then batch run and log our tests in test_config:

for t in test_config:
    print(t)
    try:
        # Check if test has input_grid
        if 'input_grid' in test_config[t]:
            # For tests with input_grid, pass the input_grid configuration
            if 'params' in test_config[t]:
                vm.tests.run_test(t, input_grid=test_config[t]['input_grid'], params=test_config[t]['params']).log()
            else:
                vm.tests.run_test(t, input_grid=test_config[t]['input_grid']).log()
        else:
            # Original logic for regular inputs
            if 'params' in test_config[t]:
                vm.tests.run_test(t, inputs=test_config[t]['inputs'], params=test_config[t]['params']).log()
            else:
                vm.tests.run_test(t, inputs=test_config[t]['inputs']).log()
    except Exception as e:
        print(f"Error running test {t}: {str(e)}")
validmind.data_validation.ClassImbalance

❌ Class Imbalance

The Class Imbalance test evaluates the distribution of target classes by measuring the percentage of observations in each class and comparing those percentages against a minimum threshold. In this run, the threshold was set to 30%, and results are reported for both raw_dataset and raw_dataset_preprocessed on the Exited target. The output table and accompanying bar charts show the class shares for Exited = 0 and Exited = 1, together with the corresponding pass/fail status for each dataset.

Key insights:

  • Raw dataset is imbalanced: In raw_dataset, Exited = 0 represents 79.80% of rows and passes the 30% threshold, while Exited = 1 represents 20.20% and fails the threshold.
  • Preprocessed dataset is balanced: In raw_dataset_preprocessed, both Exited = 0 and Exited = 1 account for 50.00% of rows, and both classes pass the 30% threshold.
  • Class proportions changed materially after preprocessing: The class distribution shifts from 79.80% / 20.20% in raw_dataset to 50.00% / 50.00% in raw_dataset_preprocessed, eliminating the failed minority-class result observed in the raw data.

The results show that class imbalance is present in the original dataset under the 30% minimum class threshold, driven by the lower prevalence of Exited = 1. In contrast, the preprocessed dataset has an even class split, and both target classes satisfy the threshold. Collectively, the test documents a clear difference in target distribution between the raw and preprocessed versions of the dataset.

Parameters:

{
  "min_percent_threshold": 30
}
            

Tables

dataset Exited Percentage of Rows (%) Pass/Fail
raw_dataset 0 79.80% Pass
raw_dataset 1 20.20% Fail
raw_dataset_preprocessed 0 50.00% Pass
raw_dataset_preprocessed 1 50.00% Pass

Figures

ValidMind Figure validmind.data_validation.ClassImbalance:b4ba
ValidMind Figure validmind.data_validation.ClassImbalance:cfdc
2026-07-31 16:47:02,415 - INFO(validmind.vm_models.result.result): Test driven block with result_id validmind.data_validation.ClassImbalance does not exist in model's document
validmind.data_validation.HighPearsonCorrelation

❌ High Pearson Correlation

The High Pearson Correlation test evaluates pairwise linear relationships among features to identify potentially redundant or highly collinear variables. The results list the strongest observed correlations for both raw_dataset and raw_dataset_preprocessed, along with the associated Pearson coefficients and pass/fail status under the configured threshold of 0.3. In the raw dataset, one feature pair exceeds the threshold and is marked Fail, while all other listed correlations in both datasets remain within the threshold and are marked Pass. The reported coefficients range from -0.3045 to 0.2810 in the raw dataset and from -0.1856 to 0.1336 in the preprocessed dataset.

Key insights:

  • One threshold breach in raw data: The pair (Balance, NumOfProducts) records a coefficient of -0.3045 in raw_dataset, making it the only listed relationship that exceeds the 0.3 threshold in absolute value and receives a Fail result.
  • Preprocessing reduced the strongest correlation: For (Balance, NumOfProducts), the coefficient decreases from -0.3045 in raw_dataset to -0.1856 in raw_dataset_preprocessed, changing from Fail to Pass under the same threshold.
  • All remaining listed correlations are below threshold: Aside from the single failed pair in raw_dataset, all other reported relationships in both datasets have absolute coefficients below 0.3, including (Age, Exited) at 0.2810 in the raw dataset, which is the largest passing correlation shown.
  • Observed linear relationships are generally weak to moderate: Most reported coefficients cluster close to zero in both datasets, with several values between approximately -0.06 and 0.06 in the preprocessed output and only a small number exceeding |0.10|.

The test results show a limited concentration of stronger linear relationships among the reported feature pairs. The only threshold exceedance appears in the raw dataset for (Balance, NumOfProducts), while the preprocessed dataset contains no reported failures and lower maximum absolute correlation values overall. Across the remaining listed pairs, coefficients stay below the configured threshold, indicating that the strongest reported linear dependency is isolated rather than widespread within the displayed results.

Parameters:

{
  "max_threshold": 0.3
}
            

Tables

dataset Columns Coefficient Pass/Fail
raw_dataset (Balance, NumOfProducts) -0.3045 Fail
raw_dataset (Age, Exited) 0.2810 Pass
raw_dataset (IsActiveMember, Exited) -0.1515 Pass
raw_dataset (Balance, Exited) 0.1174 Pass
raw_dataset (Age, IsActiveMember) 0.0873 Pass
raw_dataset (NumOfProducts, Exited) -0.0523 Pass
raw_dataset (Age, NumOfProducts) -0.0306 Pass
raw_dataset (CreditScore, IsActiveMember) 0.0306 Pass
raw_dataset (Tenure, IsActiveMember) -0.0293 Pass
raw_dataset (Age, Balance) 0.0290 Pass
raw_dataset_preprocessed (Balance, NumOfProducts) -0.1856 Pass
raw_dataset_preprocessed (IsActiveMember, Exited) -0.1733 Pass
raw_dataset_preprocessed (Balance, Exited) 0.1336 Pass
raw_dataset_preprocessed (NumOfProducts, IsActiveMember) 0.0583 Pass
raw_dataset_preprocessed (NumOfProducts, Exited) -0.0572 Pass
raw_dataset_preprocessed (CreditScore, IsActiveMember) 0.0431 Pass
raw_dataset_preprocessed (CreditScore, Exited) -0.0361 Pass
raw_dataset_preprocessed (HasCrCard, IsActiveMember) -0.0299 Pass
raw_dataset_preprocessed (Balance, HasCrCard) -0.0248 Pass
raw_dataset_preprocessed (Tenure, IsActiveMember) -0.0223 Pass
2026-07-31 16:47:13,124 - INFO(validmind.vm_models.result.result): Test driven block with result_id validmind.data_validation.HighPearsonCorrelation does not exist in model's document
Note the output returned indicating that a test-driven block doesn't currently exist in your documentation for some test IDs.

That's expected, as when we run validations tests the results logged need to be manually added to your report as part of your compliance assessment process within the ValidMind Platform.

Log tests with unique identifiers

Next, we'll use the previously initialized vm_balanced_raw_dataset (that still has a highly correlated Age column) as input to run an individual test, then log the result to the ValidMind Platform.

When running individual tests, you can use a custom result_id to tag the individual result with a unique identifier:

  • This result_id can be appended to test_id with a : separator.
  • The balanced_raw_dataset result identifier will correspond to the balanced_raw_dataset input, the dataset that still has the Age column.
result = vm.tests.run_test(
    test_id="validmind.data_validation.HighPearsonCorrelation:balanced_raw_dataset",
    params={"max_threshold": 0.3},
    inputs={"dataset": vm_balanced_raw_dataset},
)
result.log()

❌ High Pearson Correlation Balanced Raw Dataset

The High Pearson Correlation test evaluates pairwise linear relationships between features to identify potentially redundant or highly collinear variable combinations. The result table lists the strongest reported feature pairs, their Pearson correlation coefficients, and pass/fail status against the configured absolute threshold of 0.3. In this run, coefficients range from -0.1856 to 0.3416, with one pair exceeding the threshold and the remaining listed pairs falling below it.

Key insights:

  • One pair exceeds threshold: The pair (Age, Exited) has a correlation coefficient of 0.3416, which is the only listed relationship marked Fail against the 0.3 threshold.
  • Remaining listed correlations are low: All other reported feature pairs are marked Pass, with absolute correlation values at or below 0.1856, indicating materially weaker linear relationships than the top-ranked pair.
  • Largest negative correlation is limited: The strongest negative relationship in the table is (Balance, NumOfProducts) at -0.1856, which remains below the configured threshold in absolute value.
  • Most reported relationships are near zero: Several listed pairs, including (NumOfProducts, IsActiveMember) at 0.0583, (NumOfProducts, Exited) at -0.0572, and (HasCrCard, IsActiveMember) at -0.0299, show minimal linear association.

The reported correlation structure is concentrated in a single above-threshold relationship between Age and Exited, while the rest of the listed feature pairs exhibit weak linear associations relative to the configured cutoff. The strongest non-failing relationships remain well below the threshold, and multiple reported coefficients are close to zero. Overall, the table indicates a limited presence of high Pearson correlation within the top reported pairs.

Parameters:

{
  "max_threshold": 0.3
}
            

Tables

Columns Coefficient Pass/Fail
(Age, Exited) 0.3416 Fail
(Balance, NumOfProducts) -0.1856 Pass
(IsActiveMember, Exited) -0.1733 Pass
(Balance, Exited) 0.1336 Pass
(NumOfProducts, IsActiveMember) 0.0583 Pass
(NumOfProducts, Exited) -0.0572 Pass
(CreditScore, IsActiveMember) 0.0431 Pass
(Age, NumOfProducts) -0.0415 Pass
(CreditScore, Exited) -0.0361 Pass
(HasCrCard, IsActiveMember) -0.0299 Pass
2026-07-31 16:47:18,187 - INFO(validmind.vm_models.result.result): Test driven block with result_id validmind.data_validation.HighPearsonCorrelation:balanced_raw_dataset does not exist in model's document

Add test results to reporting

With some test results logged, let's head to the model we connected to at the beginning of this notebook and learn how to insert a test result into our validation report. (Learn more: Assess compliance)

While the example below focuses on a specific test result, you can follow the same general procedure for your other results:

  1. From the Inventory in the ValidMind Platform, go to the model you connected to earlier.

  2. In the left sidebar that appears for your model, click Validation under Documents.

  3. Click on 2.2.1. Data Quality to expand that section.

  4. Under the Class Imbalance Assessment guideline, click Evidence to expand the evidence panel.

  5. Click Link Evidence, then select Validator Evidence.

  6. Select the Class Imbalance test results we logged: ValidMind Data Validation Class Imbalance

    Screenshot showing the ClassImbalance test selected

  7. Click Update Linked Evidence to add the test results to the validation report.

  8. Confirm that the results for the Class Imbalance test you inserted has been correctly inserted into section 2.2.1. Data Quality of the report.

    • Note that these test results are flagged as Requires Attention — as they include comparative results from our initial raw dataset.
    • Click See evidence details to review the LLM-generated description that summarizes the test results, that confirm that our final preprocessed dataset actually passes our test:

    Screenshot showing the ClassImbalance test generated description in the text editor

Here in this text editor, you can make qualitative edits to the draft that ValidMind generated to finalize the test results.

Learn more: Work with content blocks

Preparing the preprocessed dataset

Split the preprocessed dataset

With our raw dataset rebalanced with highly correlated features removed, let's now spilt our dataset into train and test in preparation for model evaluation testing.

To start, let's grab the first few rows from the balanced_raw_no_age_df dataset we initialized earlier:

balanced_raw_no_age_df.head()
CreditScore Geography Gender Tenure Balance NumOfProducts HasCrCard IsActiveMember EstimatedSalary Exited
6811 688 Germany Female 8 150679.71 2 0 1 196226.38 0
2909 732 France Male 10 61811.23 1 1 1 104222.80 0
3481 648 Germany Male 5 138664.24 1 1 0 29076.27 0
811 807 Spain Female 1 0.00 1 1 0 16500.66 1
3134 716 Germany Male 5 121411.90 1 0 0 10070.40 1

Before training the model, we need to encode the categorical features in the dataset:

  • Use the OneHotEncoder class from the sklearn.preprocessing module to encode the categorical features.
  • The categorical features in the dataset are Geography and Gender.
balanced_raw_no_age_df = pd.get_dummies(
    balanced_raw_no_age_df, columns=["Geography", "Gender"], drop_first=True
)
balanced_raw_no_age_df.head()
CreditScore Tenure Balance NumOfProducts HasCrCard IsActiveMember EstimatedSalary Exited Geography_Germany Geography_Spain Gender_Male
6811 688 8 150679.71 2 0 1 196226.38 0 True False False
2909 732 10 61811.23 1 1 1 104222.80 0 False False True
3481 648 5 138664.24 1 1 0 29076.27 0 True False True
811 807 1 0.00 1 1 0 16500.66 1 False True False
3134 716 5 121411.90 1 0 0 10070.40 1 True False True

Splitting our dataset into training and testing is essential for proper validation testing, as this helps assess how well the model generalizes to unseen data:

  • We start by dividing our balanced_raw_no_age_df dataset into training and test subsets using train_test_split, with 80% of the data allocated to training (train_df) and 20% to testing (test_df).
  • From each subset, we separate the features (all columns except "Exited") into X_train and X_test, and the target column ("Exited") into y_train and y_test.
from sklearn.model_selection import train_test_split

train_df, test_df = train_test_split(balanced_raw_no_age_df, test_size=0.20)

X_train = train_df.drop("Exited", axis=1)
y_train = train_df["Exited"]
X_test = test_df.drop("Exited", axis=1)
y_test = test_df["Exited"]

Initialize the split datasets

Next, let's initialize the training and testing datasets so they are available for use:

vm_train_ds = vm.init_dataset(
    input_id="train_dataset_final",
    dataset=train_df,
    target_column="Exited",
)

vm_test_ds = vm.init_dataset(
    input_id="test_dataset_final",
    dataset=test_df,
    target_column="Exited",
)

In summary

In this second notebook, you learned how to:

Next steps

Develop potential challenger models

Now that you're familiar with the basics of using the ValidMind Library, let's use it to develop a challenger model: 3 — Developing a potential challenger


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