Answer:
It is important to have separate training/validation and testing sets for several reasons:
1. **Generalization**: If we test our algorithm on the training data, it is impossible to know whether it will perform well on new, unseen data. The purpose of machine learning is to build models that can generalize well to unseen data, so evaluating the model on a separate testing set helps us assess its performance in real-world scenarios.
2. **Overfitting**: When training a model, we optimize its parameters to fit the training data as closely as possible. However, this can lead to overfitting, where the model becomes too specific to the training data and fails to generalize. By using a validation set, we can tune the model's parameters to improve its performance on unseen data and prevent overfitting.
3. **Model Selection**: In machine learning, we often compare different models or variations of a model to find the best performer. The validation set allows us to evaluate the performance of different models and choose the one that works best. This helps us select a model that is likely to perform well on new data.
4. **Efficiency**: The testing set can be very large, and processing it can be time-consuming. To quickly figure out model parameters and tune the model, it is more efficient to have smaller training and validation sets. This allows us to iterate and experiment with different approaches more rapidly.
In summary, having separate training/validation and testing sets is crucial for evaluating a model's ability to generalize, avoiding overfitting, selecting the best model, and ensuring efficiency in the model development process.
Step-by-step explanation: