Last Updated on July 25, 2023 by Editorial Team
Author(s): Hrvoje Smolic
Originally published on Towards AI.
Data is the lifeblood of machine learning. Without data, there would be no way to train and evaluate ML models. But how much data do you need for machine learning? In this blog post, we’ll explore the factors that influence the amount of data required for an ML project, strategies to reduce the amount of data needed, and tips to help you get started with smaller datasets.
Machine learning (ML) and predictive analytics are two of the most important disciplines in modern computing. ML is a subset of artificial intelligence (AI) that focuses on building models that can learn from data instead of relying on explicit programming instructions. On the other hand, data science is an interdisciplinary field that uses scientific methods, processes, algorithms, and systems to extract knowledge and insights from structured and unstructured data.
As ML and data science have become increasingly popular, one of the most commonly asked questions is: how much data do you need to build a machine learning model?
The answer to this question depends on several factors, such as the
- type of problem being solved,
- the complexity of the Model,
- accuracy of the data,
- and availability of labeled data.
A rule-of-thumb approach suggests that it’s best to start with around ten times more samples than the number of features in your dataset.
Additionally, statistical methods such as power analysis can help you estimate sample size for various types of machine-learning problems. Apart from collecting more data, there are specific strategies to reduce the amount of data needed for an ML model. These include feature selection techniques such as LASSO regression or principal component analysis (PCA). Dimensionality reduction techniques like autoencoders, manifold learning algorithms, and synthetic data generation techniques like generative adversarial networks (GANs) are also available.
Although these techniques can help reduce the amount of data needed for an ML model, it is essential to remember that quality still matters more than quantity when it comes to training a successful model.
How Much Data is Needed?
Factors that influence the amount of data needed
When it comes to developing an effective machine learning model, having access to the right amount and quality of data is essential. Unfortunately, not all datasets are created equal, and some may require more data than others to develop a successful model. We’ll explore the various factors that influence the amount of data needed for machine learning as well as strategies to reduce the amount required.
Type of Problem Being Solved
The type of problem being solved by a machine learning model is one of the most important factors influencing the amount of data needed.
For example, supervised learning models, which require labeled training data, will typically need more data than unsupervised models, which do not use labels.
Additionally, certain types of problems, such as image recognition or natural language processing (NLP), require larger datasets due to their complexity.
The complexity of the Model
Another factor influencing the amount of data needed for machine learning is the complexity of the Model itself. The more complex a model is, the more data it will require to function correctly and accurately make predictions or classifications. Models with many layers or nodes will need more training data than those with fewer layers or nodes. Also, models that use multiple algorithms, such as ensemble methods, will require more data than those that use only a single algorithm.
Quality and Accuracy of the Data
The quality and accuracy of the dataset can also impact how much data is needed for machine learning. Suppose there is a lot of noise or incorrect information in the dataset. In that case, it may be necessary to increase the dataset size to get accurate results from a machine-learning model.
Additionally, suppose there are missing values or outliers in the dataset. In that case, these must be either removed or imputed for a model to work correctly; thus, increasing the dataset size is also necessary.
Estimating the amount of data needed
Estimating the amount of data needed for machine learning (ML) models is critical in any data science project. Accurately determining the minimum dataset size required gives data scientists a better understanding of their ML project’s scope, timeline, and feasibility.
When determining the volume of data necessary for an ML model, factors such as the type of problem being solved, the complexity of the Model, the quality and accuracy of the data, and the availability of labeled data all come into play.
Estimating the amount of data needed can be approached in two ways:
- A rule-of-thumb approach
- or statistical methods
to estimate sample size.
The rule-of-thumb approach is most commonly used with smaller datasets. It involves taking a guess based on past experiences and current knowledge. However, it is essential to use statistical methods to estimate sample size with larger datasets. These methods allow data scientists to calculate the number of samples required to ensure sufficient accuracy and reliability in their models.
Generally speaking, the rule of thumb regarding machine learning is that you need at least ten times as many rows (data points) as there are features (columns) in your dataset.
This means that if your dataset has 10 columns (i.e., features), you should have at least 100 rows for optimal results.
Recent surveys show that around 80% of successful ML projects use datasets with more than 1 million records for training purposes, with most utilizing far more data than this minimum threshold.
Data Volume & Quality
When deciding how much data is needed for machine learning models or algorithms, you must consider both the volume and quality of the data required.
In addition to meeting the ratio mentioned above between the number of rows and the number of features, it’s also vital to ensure adequate coverage across different classes or categories within a given dataset, otherwise known as class imbalance or sampling bias problems. Ensuring a proper amount and quality of appropriate training data will help reduce such issues and allow prediction models trained on this larger set to attain higher accuracy scores over time without additional tuning/refinement efforts later down the line.
Rule-of-thumb about the number of rows compared to the number of features helps entry-level Data Scientists decide how much data they should collect for their ML projects.
Thus ensuring that enough high-quality input exists when implementing Machine Learning techniques can go a long way towards avoiding common pitfalls like sample bias & underfitting during post-deployment phases. It is also helping achieve predictive capabilities faster & within shorter development cycles, irrespective of whether one has access to vast volumes of data.
Strategies to Reduce the Amount of Data Needed
Fortunately, several strategies can reduce the amount of data needed for an ML model. Feature selection techniques such as principal component analysis (PCA) and recursive feature elimination (RFE) can be used to identify and remove redundant features from a dataset.
Dimensionality reduction techniques such as singular value decomposition (SVD) and t-distributed stochastic neighbor embedding (t-SNE) can be used to reduce the number of dimensions in a dataset while preserving important information.
Finally, synthetic data generation techniques such as generative adversarial networks (GANs) can be used to generate additional training examples from existing datasets.
Tips to Reduce the Amounts of Data Needed for an ML Model
In addition to using feature selection, dimensionality reduction, and synthetic data generation techniques, several other tips can help entry-level data scientists reduce the amount of data needed for their ML models.
First, they should use pre-trained models whenever possible since these models require less training data than custom models built from scratch. Second, they should consider using transfer learning techniques which allow them to leverage knowledge gained from one task when solving another related task with fewer training examples.
Finally, they should try different hyperparameter settings since some settings may require fewer training examples than others.
Examples of Successful Projects with Smaller Datasets
Data is an essential component of any machine learning project, and the amount of data needed can vary depending on the complexity of the Model and the problem being solved.
However, it is possible to achieve successful results with smaller datasets.
We will now explore some examples of successful projects completed using smaller datasets. Recent surveys have shown that many data scientists can complete successful projects with smaller datasets.
According to a survey conducted by Kaggle in 2020, nearly 70% of respondents said they had completed a project with fewer than 10,000 samples. Additionally, over half of the respondents said they had completed a project with fewer than 5,000 samples.
Numerous examples of successful projects have been completed using smaller datasets. For example, a team at Stanford University used a dataset of only 1,000 images to create an AI system that could accurately diagnose skin cancer.
Another team at MIT used a dataset of only 500 images to create an AI system that could detect diabetic retinopathy in eye scans.
These are just two examples of how powerful machine learning models can be created using small datasets.
It is evidently possible to achieve successful results with smaller datasets for machine learning projects.
By utilizing feature selection techniques and dimensionality reduction techniques, it is possible to reduce the amount of data needed for an ML model while still achieving accurate results.
At the end of the day, the amount of data needed for a machine learning project depends on several factors, such as the type of problem being solved, the complexity of the Model, the quality and accuracy of the data, and the availability of labeled data. To get an accurate estimate of how much data is required for a given task, you should use either a rule-of-thumb or statistical methods to calculate sample sizes. Additionally, there are effective strategies to reduce the need for large datasets, such as feature selection techniques, dimensionality reduction techniques, and synthetic data generation techniques.
Finally, successful projects with smaller datasets are possible with the right approach and available technologies.
Originally published at https://graphite-note.com on December 15, 2022.
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Published via Towards AI