Blenders and Ensembles

cancel
Showing results for 
Search instead for 
Did you mean: 

We're looking into an issue with broken attachments right now. Please stay tuned!

Blenders and Ensembles

Ensemble learning allows you to create more accurate models by combining the power of multiple models: DataRobot calls these types of models “blenders.”

Figure 1: Ensemble LearningFigure 1: Ensemble Learning

Blending and Stacking

DataRobot uses two major techniques to create blenders. The first is to simply take the means or medians over several models for each observation and use that as a prediction. The second is to take the predictions from several models and use them as features in a final model; this is called stacking (Figure 2).

Figure 2: Ensemble exampleFigure 2: Ensemble example

  

Why is this done?

  1. Creating blenders often results in more accurate models.
  2. Blenders allow you to use multiple blueprints.
  3. And blenders allow you to leverage the wisdom of crowds principles.

What are some considerations?

  1. It is generally advised to blend models that rely on different algorithms and have good accuracy.
  2. While blenders can give you a boost in accuracy, they can often take more time to create and score because they are more complex.
  3. Blender models can make the final model more complicated to communicate to regulators; however, DataRobot model interpretability tools and documentation can help you with this process.

Leaderboard

By default, DataRobot will create four blenders for each Autopilot run (Figure 3). This includes two blenders that blend the top 3 models and two blenders that blend the top 8 models.

Figure 3. LeaderboardFigure 3. Leaderboard

Blueprints

If you're curious about any of these models, all you have to do is click on the blender (model) and the blender blueprint will be displayed (Figure 4).

You can see within this blueprint the preprocessing steps for the blender. Notice that these steps include other models that you can find on the Leaderboard.

The final step is the actual blending. If you want to look at any of these steps in more detail you can simply click one of the blueprint boxes and, in the displayed pop-up, select to view DataRobot Model Docs.

Figure 4. BlueprintFigure 4. Blueprint

Evaluation

The same metrics that you use to evaluate and interpret your other models apply here as well (see Figure 5).

Figure 5. EvaluationFigure 5. Evaluation

Interpreting Models

You can also go to the Understand division to see Feature Impact, Feature Effects, and Prediction Explanations (Figure 6).

Figure 6. InterpretationFigure 6. Interpretation 

Create your own blender

If you want to create your own blender, all you have to do is select models that you want to blend. These two strategies can help you get the most out of your blenders.

  1. Stay near the top of the leaderboard, so you will use the most accurate models.
  2. Use models that rely on different algorithms.

You can then simply go to the menu and, under the section called blending, you can select a number of different types of blenders (Figure 7).

Figure 7. Types of blendersFigure 7. Types of blenders

This is going to start the blending process and you can see this processing on the right-hand side of the screen. When the blender is complete, it will be added to the Leaderboard and ranked among the other models that you've created.

Comments
manohariika
Blue LED

This document gives great knowledge on how to use DataRobot and various options. I started using this since a week and so interesting to learn. I would like to understand more on 'Blending the models'. Also I want to learn more on how to use this to detect the objects in a picture.

Appreciate your reply.

Thank you,

Manohar

lhaviland
Community Team
Community Team

Hi @manohariika - Here are a couple more community resources that will help you understand blended models and understand how DataRobot blends models:

The Value of Blended Teams in DataRobot
How do the different blenders work?
How do I create my own blenders?
How does DataRobot decide which blenders to run?

And see how DataRobot's model comparison tools works with blended models:
Comparing Models Overview 

I believe you're using DataRobot AI Trial? If so, look here (in the in-app Platform docs) for details on how DataRobot creates blended models.

And, if you still have questions after checking out these resources, please let me know!

-linda

Version history
Last update:
4 weeks ago
Updated by:
Contributors