What are the Various Types of Data Sets Used in Machine Learning?

June 2, 2019 4 min read By Cogito Tech. 1119 views

What are the various Types of Datasets used in Machine Learning?

Machine learning models are built with the help of datasets used at various stages of development. Different types of datasets are used in machine learning of AI-based model development, like training data, validation data, and test datasets.

The questions are why data is split and what are these data types. The data is split into different types of training, validation, and test data, and here we will discuss what these types of data are and where or how they are used in various stages of machine learning development.

Why is Data Split into Various Types?

Developing a machine learning model is the process that extrapolates to input samples that it has never noticed before. This kind of work needs to expose the ML model to a certain number of data inputs to make the output accuracy at the best level. And these data inputs are split into multiple steps, and each model has to go through before it is used in real life.

#1 Data Examination by ML Model

#2 Model Learning from Mistakes

#3 Output Quality and Accuracy Check

As you can see, each step is different, resulting in each data being treated differently at different stages of model development. Hence, we need to decide here which data in the dataset plays a vital role in which stage of ML development.

Training Datasets

machine learning datasets

This is the first stage of datasets that comprises a set of input examples that the model will be fit into or used to train the model while adjusting the various parameters like weights, height, and other factors in the context of neural networks. Simply, training datasets are used to train the model with data gathered in real life as machine learning training data.

Validation Datasets

The second stage is evaluating the model predictions and learning from mistakes before validating the datasets. Through the evolution process, estimating the mistakes or the losses the model yields on the validation set at any given point of time. It helps to know the machine learning engineers how accurate the model output which is very much important. It helps to tune its parameters depending on the frequent evaluation results on the validation set.

Testing Datasets

This dataset type is the final evaluation that a model needs to go through after the training stage in model development. This step is critical to test the final testing of the model, which helps with generalizability and finding out the working accuracy of the model. However, every AI or machine learning engineer needs to be subjective and unbiased by exposing such models to the test set only after the training phase is fully completed. This kind of positive approach in ML model training development is considered the final accuracy measure to be reliable.

The machine learning model training involves looking at training examples and learning from how much the model is inaccurate by evaluating through the ML model validation datasets. However, the most critical indicator of the accuracy of a model is a result of testing the model on the testing set when the model training is fully completed to ensure it can work with the best accuracy without showing any inaccuracy.

Determining the Size, Quality, and Reliability of Datasets

Having determined the category of the datasets for the machine learning model, the course comes to deciding on the size and quality of the datasets as the size and quality of the datasets matter the most to the functionality of the machine learning model. 

As you know, a model is only as good as the data it is fed with, but how can your datasets be improved, and how can you measure its quality? Depending on the type of problem you’re trying to solve, how much data you need will determine whether you get useful results. 

Size of the Datasets

The size of datasets determines a machine learning model’s success; the larger the dataset, the better it will perform when it comes to automation and prediction. More data means your machine learning model can recognize more objects, resulting in a better computer vision system

Quality of the Datasets 

If the data is bad, then it makes no sense to have a lot of it; quality is also important. But what is quality? A more concrete definition of quality would be helpful. Consider taking a more empirical approach and choosing the option that produces the best outcomes. As a result, a quality data set is one that enables you to address your business problem. Alternatively, the data is good if it fulfills its purpose. 

Reliability of the Datasets 

Datasets that you collect, compile, and tune in to integrate into your machine-learning model need to hold the reliability. The reliability of your data refers to its level of trustworthiness for the functionality of the machine learning model. The reliability of a model is determined by how it responds when trained on reliable data compared to an unreliable data set. 

To determine reliability, you must determine the following:

I. If the datasets are properly filtered;

II. If the datasets are clean and clutter-free, i.e., the data doesn’t consist much of unused data;

III. If the data is relevant to the industry that your machine learning model is designed for;

IV. If the data is not too noisy or blurry to be read by the machine or to be fed into the machine learning model.

To ensure that the datasets you choose to use for the machine learning model are reliable, make sure that it does not have any omitted values that are necessarily required for the functionality of the machine learning model. Also, check if there is any duplicity in the datasets. Inappropriate labels and feature values of objects and elements in the datasets may also lead to their unreliability for machine integration.


The datasets are crucial to the success of the machine learning model as it determines how functional the model will be to address the problem it has been designed for. Thus, it is significant to wisely pick, procure and process the datasets you want to use for your machine learning models. Or, better would be to have an industry expert by your side to get the job done so that you can focus on other vital parts of the course. 

Cogito, Anolytics, and sort of others are the leading data processing companies, and you can hold your faith in the to be your source for high-quality AI training data for your machine learning model. With help from experts for machine learning datasets, you can be sure to have a well-functional model that addresses the problem it’s designed for.

If you wish to learn more about Cogito’s data annotation services,
please contact our expert.