Naomi Teng
joined June 29, 2025
  • How to handle imbalanced datasets effectively in classification problems?

    I’m working on a classification problem where one class heavily outweighs the others (around 90:10 ratio). My model is achieving high accuracy, but it’s clearly biased toward the majority class. Here’s a simplified version:   from sklearn.model_selection import train_test_splitfrom sklearn.ensemble import RandomForestClassifierfrom sklearn.metrics import classification_report X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2) model =(Read More)

    I’m working on a classification problem where one class heavily outweighs the others (around 90:10 ratio). My model is achieving high accuracy, but it’s clearly biased toward the majority class.

    Here’s a simplified version:

     
    from sklearn.model_selection import train_test_split
    from sklearn.ensemble import RandomForestClassifier
    from sklearn.metrics import classification_report

    X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2)

    model = RandomForestClassifier()
    model.fit(X_train, y_train)

    y_pred = model.predict(X_test)
    print(classification_report(y_test, y_pred))

     

    Accuracy looks good, but recall and precision for the minority class are poor.

    What I want to understand:

    • What are the best techniques to handle imbalance (SMOTE, class weights, etc.)?
    • When should I prefer resampling vs adjusting model parameters?
    • Which evaluation metrics should I focus on in such cases?

    Would appreciate practical advice based on real-world experience.

     
     
  • How to handle dynamic schema changes in Alteryx workflows?

    I’m working on an Alteryx workflow where the input data schema changes frequently (new columns get added, some get removed, and column order varies). This is causing issues with tools like Select, Join, and Union, where the workflow breaks if expected fields are missing or renamed. For example, I’m reading multiple files: Input Data →(Read More)

    I’m working on an Alteryx workflow where the input data schema changes frequently (new columns get added, some get removed, and column order varies).

    This is causing issues with tools like Select, Join, and Union, where the workflow breaks if expected fields are missing or renamed.

    For example, I’m reading multiple files:

    Input Data → Select → Join → Output
    

    But when a new column appears in one file or a column is missing in another, the workflow fails or produces inconsistent output.

    What I’ve tried:

    • Using Auto Config by Name in Union

    • Dynamic Rename tool

    • Select with “Unknown” fields

    Still facing issues with joins and downstream tools.

    My questions:

    • What’s the best way to make Alteryx workflows resilient to schema changes?

    • Are there recommended patterns or tools (Dynamic Input, Field Info, etc.) for handling this?

    • How do you ensure joins don’t break when fields are inconsistent?

    Would appreciate any best practices or real-world approaches.

  • Why does my deep learning model do well on training data but poorly on validation?

    I’m new to deep learning and currently training my first few neural network models. During training, the accuracy keeps improving and the loss goes down nicely. But when I evaluate the model on validation data, the performance drops a lot. This feels confusing because the training results look “good” at first glance. I’m trying to(Read More)

    I’m new to deep learning and currently training my first few neural network models.

    During training, the accuracy keeps improving and the loss goes down nicely. But when I evaluate the model on validation data, the performance drops a lot. This feels confusing because the training results look “good” at first glance.

    I’m trying to understand this at a conceptual level, not just apply fixes blindly.

    Some things I’m wondering about:

    • What are the most common reasons this happens for beginners?
    • How do you tell if this is overfitting versus a data or setup issue?
    • Are there simple checks or habits I should build early to avoid this?
    • At what point should I worry, and when is this just part of learning?

    Looking for intuition, mental models, and beginner-friendly explanations rather than advanced math or theory.

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