WHAT IS SYNTHETIC DATA AND HOW TO CREATE IT?

What is synthetic data and how to create it? leewayhertz.com/what-is-synthetic-data

In this era of data-driven innovations, the demand for diverse, high-quality, reliable data is constantly rising. However, accessing and utilizing real-world data can often be challenging due privacy concerns, limited availability, or costly data collection processes.

Synthetic data offers a promising solution to these limitations, enabling researchers, developers, and organizations to unlock the full capabilities and benefits of working with data-driven applications.

Synthetic data refers to artificially generated data that replicates the statistical properties and characteristics of real data without containing any identifiable or sensitive information.

Because of its ability to simulate realistic data scenarios, synthetic data has become a powerful means for: Training machine learning models.

Validating algorithms.

Conducting research.

Addressing various data-related challenges across multiple domains.

This article delves into the realm of synthetic data, exploring its applications, benefits, and the significant impact it can have on various industries. From healthcare and finance to cybersecurity and autonomous vehicles, synthetic data is redefining how data is utilized, enabling organizations to innovate and make data-driven decisions while maintaining privacy and mitigating data scarcity issues.

What is synthetic data?

Importance of synthetic data 1/14

Types of synthetic data Techniques to generate synthetic data How to create synthetic data Synthetic data use cases and applications Comparison with real data Best practices for creating synthetic data

What is synthetic data?

Synthetic data is artificially generated data that imitates real-world data. It is created using statistical models and machine learning algorithms to produce data that resembles real data but doesn’t contain identifiable information about individuals or entities. Synthetic data can be used as an alternative to real data when access to real data is limited or restricted or when using real data would cause privacy concerns or legal issues.

One advantage of synthetic data is that it allows researchers and developers to create and test algorithms and models without risking the exposure of sensitive or private data. It can also be used to create diverse and representative datasets and fill existing data gaps.

Generating synthetic data involves creating a model based on existing data and then using that model to generate new data with similar statistical properties to the original data. The model can be adjusted to produce data with different levels of complexity, variation, and noise. However, it is important to ensure that the synthetic data accurately represents the real-world data and does not introduce any biases or inaccuracies.

Importance of synthetic data Synthetic data is becoming increasingly important in various industries and applications due to the following reasons: 1. Data privacy: With the growing concern over data privacy, accessing real-world data containing personal information is becoming difficult. Synthetic data can be used to train ML models without risking the privacy of individuals.

2. Data diversity: Real-world data is often limited in terms of diversity, which can lead to biased or inaccurate models. Synthetic data can be utilized to augment real-world data and increase the diversity of the dataset.

3. Cost-effective: Synthetic data is generally less expensive to generate than realworld data, as it requires no data collection efforts or resources.

4. Scalability: Generating synthetic data can be done at scale. You can quickly generate large datasets to train machine learning models, which is difficult to achieve with real-world data.

5. Model testing: Synthetic data can be used to test the robustness of machine learning models and identify potential weaknesses without risking the safety or privacy of real-world individuals.

2/14

Overall, synthetic data can be an important tool for organizations to improve the accuracy and efficiency of machine learning models without incurring the risks associated with realworld data collection and privacy concerns.

Types of synthetic data As artificially generated data, synthetic data aims to protect sensitive private information while retaining real data’s statistical properties. It can be classified into three core types: fully synthetic data, partially synthetic data, and hybrid synthetic data.

Fully synthetic data Fully synthetic data is entirely synthetic and contains no information from the original data. The data generator for this type of synthetic data identifies the density function of features in the real data and estimates their parameters. Then, privacy-protected series are generated randomly from the estimated density functions. Suppose only a few features of the real data are selected for replacement with synthetic data. In that case, the protected series of these features are mapped to the other features of the real data to rank the protected series and the real series in the same order. Bootstrap methods and multiple imputations are classic techniques used to generate fully synthetic data.

Partially synthetic data Partially synthetic data replaces only the values of selected sensitive features with synthetic values. Real values are replaced only if they contain a high risk of disclosure, which is done to preserve privacy in the newly generated data. Techniques used to generate partially synthetic data are multiple imputation and model-based techniques, which are also helpful for imputing missing values in real data.

Hybrid synthetic data Hybrid synthetic data combines both real and synthetic data. A close record in the synthetic data is chosen for each random record of real data, and then both are combined to form hybrid data. This type of synthetic data provides the advantages of both fully and partially synthetic data. It is known to provide good privacy preservation with high utility compared to the other two, but at the expense of more memory and processing time.

Techniques used to generate synthetic data There are multiple techniques to generate synthetic data, out of which these are the most prominent: 1. Drawing numbers from a distribution Drawing numbers from a distribution is a popular technique for generating synthetic data, which involves sampling numbers from a distribution to create a dataset that follows a curve based on real-world data. Python and NumPy libraries are commonly used to

3/14

create a set of datasets using a “normal” distribution of variables, each with a slight change to the centerpoint.

2. Agent-based Modeling (ABM) Agent-based modeling is a simulation technique where individual agents interact with each other in a complex system. ABM is useful for examining interactions between agents such as people, cells, or computer programs. Python packages such as Mesa can quickly create agent-based models using built-in core components and visualize them in a browser-based interface.

3. Generative models Generative modeling is one of the most refined techniques used to generate synthetic data. It involves automatically discovering and learning insights and patterns in data to generate new examples that correspond to the same distribution as the real-world data it was trained on.

There are two common approaches to generative models: a) Generative Adversarial Networks (GANs): GANs treat the training process as a contest between two separate networks – a generator network and a discriminative network that attempts to classify samples as the ones from the real world or the fake ones generated by the model. The generator adjusts its model parameters on each training iteration to generate more convincing examples to fool the discriminator.

How does a GAN model work?

Real/training data sample

Randomdata data Random samples samples

Generator

Fine tune training

Discriminator

classifies as real/fake

Generated data sample Fine tune training

LeewayHertz

b) Language Models (LM): LM attempts to learn the underlying probability allocation of the training data, such as a series of text or tokens, so that it can effortlessly sample new data from that learned distribution or predict the next token or words in a sentence. They can learn and recreate short and longer texts by training on massive amounts of data.

Recurrent Neural Networks (RNN) and Transformers are common types of language models used for generating synthetic data.

4/14

How to create synthetic data?

Let us explore the process of synthetic data generation using Python.

Import the dependencies To generate synthetic data, first, we need to import the prerequisites. In this case, we must import libraries and modules such as NumPy, Pandas, Matplotlib.pyplot and Make_classification from Scikit-learn. import numpy as np import pandas as pd from sklearn.datasets import make_classification import matplotlib.pyplot as plt from matplotlib import rcParams step=6 In the above code snippet, the line “step=6” is a variable where it is given a value of 6. It serves as a control variable to determine which steps or sections of the code to execute.

Assign specific characteristics to datasets Run the following code to modify some specific parameters of the ‘rcParams’ dictionary object, namely, the ‘axes.spines.top’ and the ‘axes.spines.right’. rcParams['axes.spines.top'] = False rcParams['axes.spines.right'] = False Next, generate a synthetic classification dataset using the ‘make_classification’ function from the scikit-learn library and assign values to each data necessity, like the number of samples and features.

X, y = make_classification( n_samples=1000, n_features=2, n_redundant=0, n_clusters_per_class=1, random_state=42, weights=[0.50] 5/14

) Manipulate the data Here, we need to concatenate the feature array X and the label array y into a DataFrame df, assign appropriate column names, and print a sample of random rows from the DataFrame if the value of step is equal to 1. This is beneficial in inspecting the data and understanding its structure. df = pd.concat([pd.DataFrame(X), pd.Series(y)], axis=1) df.columns = ['x1', 'x2', 'y'] if(step==1): print(df.sample(10)) Visualize the dataset Define a reusable function, ‘plot’ to create a scatterlot and visualize a dataset with two classes. def plot(df: pd.DataFrame, x1: str, x2: str, y: str, title: str = '', save: bool = False, figname='figure.png'): plt.figure(figsize=(14, 7)) plt.scatter(x=df[df[y] == 0][x1], y=df[df[y] == 0][x2], label='y = 0') plt.scatter(x=df[df[y] == 1][x1], y=df[df[y] == 1][x2], label='y = 1') plt.title(title, fontsize=20) plt.legend() if save: plt.savefig(figname, dpi=300, bbox_inches='tight', pad_inches=0) plt.show() if(step==2): plot(df=df, x1='x1', x2='x2', y='y', title='Dataset with 2 classes') Generate a synthetic classification dataset Next, we will generate a synthetic classification dataset using the ‘make_classification’ function from the ‘sklearn.datasets’ module.

X, y = make_classification( 6/14

n_samples=1000, n_features=2, n_redundant=0, n_clusters_per_class=1, flip_y=0.25, random_state=42 ) The generated synthetic data will have 1000 samples and two features. It is designed to mimic a real-world scenario with minimal redundancy and no significant clustering within each class. Additionally, a small amount of label flipping is introduced to create some noise in the dataset.

Create a new DataFrame Next, create a new DataFrame ‘df’ by concatenating the feature and target variable arrays. Then assign meaningful column names to the DataFrame. df = pd.concat([pd.DataFrame(X), pd.Series(y)], axis=1) df.columns = ['x1', 'x2', 'y'] Next, we need to visually analyze and understand the impact of class imbalance on the dataset. if(step==4): plot(df=df, x1='x1', x2='x2', y='y', title='Dataset with 2 classes - Class imbalance (weights=0.95)') X, y = make_classification( n_samples=1000, n_features=2, n_redundant=0, n_clusters_per_class=1, weights=[0.05], random_state=42 ) 7/14

In the above code snippet, if the ‘step’ variable is equal to 4, it calls the plot function with the updated dataset to generate a plot representing the dataset with class imbalance (using a weight of 0.95 for one class).

Reiterate the above code step to generate synthetic classification datasets with varying class imbalances and visualize them using scatter plots. The plots help understand the impact of class imbalance on the dataset and can provide insights into the classification problem.

You can access the whole set of code from this GitHub repository.

Synthetic data use cases and applications Synthetic data has emerged as a powerful tool with many real-world applications across industries. By artificially generating data that closely resembles real-world information, organizations can address privacy concerns, enhance machine learning models, and overcome data limitations. From healthcare and finance to autonomous vehicles and gaming, synthetic data empowers researchers, data scientists, and engineers to train algorithms, test hypotheses, and simulate scenarios in a privacy-preserving and efficient manner. Synthetic data use cases and applications can be summarized into the following:

Training machine learning models Synthetic data has emerged as a valuable resource with a wide range of applications. It is extensively used for training machine learning models when access to real-world data is limited, expensive, or sensitive. By generating artificial data that mimics the statistical properties of real data, synthetic data enables comprehensive model training and enhances generalization capabilities. It also addresses data scarcity and imbalance issues by augmenting datasets with diverse instances and variations.

Testing and validation Synthetic data can be used to simulate various scenarios and test the performance of models under different conditions. Developers can evaluate how well their models generalize and make predictions in diverse situations by generating synthetic data that represents different patterns, distributions, or anomalies.

One use case for synthetic data in testing and validation is assessing the robustness and accuracy of models. Developers can introduce synthetic perturbations or adversarial examples into the dataset to evaluate how the model handles unexpected inputs or attempts at manipulation. This helps uncover potential vulnerabilities or weaknesses in the model’s performance and aids in fine-tuning and improving its resilience.

Data augmentation

8/14

Data augmentation is a technique typically used in machine learning to elaborate the size and diversity of a training dataset. One use case for synthetic data in data augmentation is when the available real-world data is limited or insufficient to train a robust model. In such cases, synthetic data can be generated to expand the dataset and provide additional samples for training. By mimicking the statistical properties and patterns of the real data, synthetic data can effectively supplement the existing dataset and help address the problem of data scarcity.

Synthetic data can also be beneficial in situations where real-world data is imbalanced or biased. Imbalanced datasets, where one class or category is underrepresented, can lead to biased model predictions. The dataset can be rebalanced by generating synthetic data for the underrepresented class, allowing the model to learn from a more equitable distribution.

Anonymization Anonymization is a critical process in data privacy and security, especially when handling sensitive or personally identifiable information (PII). Synthetic data offers a valuable use case in anonymization by providing an alternative to real data that retains statistical properties and patterns while removing any direct identifiers. This allows organizations to share datasets for research, collaboration, or analysis purposes without compromising individual privacy or violating privacy regulations.

By replacing real data with synthetic equivalents, organizations can protect individuals’ identities while preserving the original dataset’s overall structure and characteristics.

Synthetic data generation techniques ensure that the statistical properties, distributions, and relationships present in the real data are maintained, making it useful for conducting various analyses and research studies. However, as synthetic data is not directly linked to any individual, it eliminates the risk of re-identification.

The use of synthetic data in anonymization has become particularly important with the increasing focus on privacy and data protection. Many privacy regulations, like the General Data Protection Regulation (GDPR), require organizations to ensure that personal data is pseudonymized or anonymized before it is shared or used for research purposes. Synthetic data serves as a viable solution in achieving this anonymization objective, as it allows organizations to create privacy-preserving datasets that can be used by researchers, data scientists, or other stakeholders without compromising the privacy rights of individuals.

In summary, the use of synthetic data in anonymization enables organizations to protect individual privacy while still enabling the sharing and utilization of datasets. By replacing identifiable information with synthetic counterparts, organizations can comply with privacy regulations, facilitate research collaborations, and perform analyses without compromising the confidentiality and privacy of individuals. Synthetic data strikes a

9/14

harmonious balance between the necessity of data sharing and collaboration while upholding the crucial aspects of privacy and data protection, offering a practical and effective solution.

Simulation and modeling Synthetic data plays a crucial role in simulation and modeling, where it serves as a valuable tool for creating virtual environments and scenarios that closely resemble realworld conditions. By generating synthetic data, researchers and analysts can simulate various scenarios, test hypotheses, and evaluate the performance of systems or models without relying solely on real data, which can be limited or difficult to obtain.

One use case of synthetic data in simulation and modeling is in the field of computer graphics and animation. Synthetic data is used to generate realistic 3D models, textures, and animations that mimic real-world objects and environments. This enables the creation of virtual worlds for video games, movies, and other virtual reality experiences. By leveraging synthetic data, designers and developers can simulate physics, lighting, and other real-world phenomena to enhance these virtual environments’ visual fidelity and immersive nature.

Marketing and advertising Synthetic data plays a crucial role in marketing and advertising, providing valuable insights and solutions to improve campaign effectiveness and targeting. It can be used to create synthetic customer profiles that represent different target audience segments. By analyzing these profiles, marketers can gain insights into their target customers’ characteristics, preferences, and behaviors.

Synthetic data can be used for A/B testing and campaign optimization. Marketers can create synthetic datasets that simulate user interactions with different variations of marketing campaigns, such as different ad creatives, messaging, or landing pages. By analyzing the performance of these synthetic datasets, marketers can gain insights into the efficiency of different campaign elements and optimize their strategies accordingly.

Gaming and entertainment Synthetic data plays a significant role in the gaming and entertainment industry, providing valuable resources for creating immersive and engaging experiences. It can be used to generate virtual characters, creatures, and worlds in video games and other virtual reality (VR) experiences. By utilizing synthetic data, game developers can create diverse and realistic characters with unique attributes, behaviors, and appearances.

Procedural generation algorithms leverage synthetic data to generate terrain, landscapes, buildings, and other elements within the game world. This allows for the creation of expansive and diverse game worlds without the need for manual design of each individual element, resulting in more immersive and varied gameplay experiences.

10/14

Motion capture technology captures real-world human movements and converts them into synthetic data, which is then applied to virtual characters. This process enables game developers and animators to achieve highly realistic animations that accurately replicate human motion and behavior, enhancing the visual quality and realism of characters within games and animated films.

Moreover, VFX artists use synthetic data to simulate and create realistic simulations of natural phenomena, such as explosions, fire, water, and particle effects. By leveraging synthetic data, VFX artists can achieve stunning and visually compelling effects that enhance the overall visual experience for audiences.

Medical research Synthetic data can be utilized in clinical trials and experimental studies to simulate patient populations. Researchers can generate synthetic datasets that mimic the characteristics of target populations, allowing them to design and test protocols, evaluate treatment outcomes, and assess the feasibility of different interventions. Synthetic data enables researchers to conduct virtual trials and simulations without involving actual patients, reducing costs, time, and ethical concerns.

Synthetic data also finds application in statistical analysis and epidemiological studies.

Researchers can generate synthetic datasets that adhere to specific epidemiological characteristics, disease prevalence, or risk factors. These datasets can be used for exploratory analysis, hypothesis testing, and modeling the spread of diseases. Synthetic data facilitates population-level studies while preserving individual privacy.

Fraud detection Synthetic data can be used to detect fraudulent activities in financial transactions while preserving the privacy of the individuals involved. It allows financial institutions to analyze patterns and trends associated with fraudulent activities. By generating synthetic datasets that mimic the statistical properties and characteristics of real transaction data, analysts can identify common patterns and anomalies that indicate potential fraudulent behavior.

Synthetic data enables the development and testing of fraud detection algorithms without exposing actual customer information.

Autonomous vehicle testing Synthetic data can be leveraged to train and test autonomous vehicle algorithms to avoid accidents and improve safety. By generating synthetic sensor data, such as images, LiDAR point clouds, and radar signals, developers can create diverse and challenging driving scenarios that mimic the complexities of the actual road conditions. This enables extensive testing of autonomous vehicle systems without the need for physical prototypes or risking safety on real roads.

11/14

Synthetic data enables the simulation of rare and hazardous driving scenarios that are challenging to encounter in real-world testing. This includes scenarios such as extreme weather conditions, complex intersections, unpredictable pedestrian behaviors, or rare edge cases. Autonomous vehicle systems can be thoroughly tested and optimized for safety and performance by incorporating synthetic data representing these scenarios.

Cybersecurity The use of synthetic data in cybersecurity has emerged as a valuable tool for enhancing security measures and protecting sensitive information. It can be used to generate simulated network traffic, mimicking various attack patterns and behaviors. By feeding this synthetic data into intrusion detection systems, security analysts can train and finetune Intrusion Detection Systems (IDS) to recognize and respond to different types of cyber attacks. Synthetic data helps in creating realistic attack scenarios without compromising the security of actual network systems.

By generating synthetic data representing known vulnerabilities and attack vectors, security teams can proactively identify and mitigate vulnerabilities. Synthetic data allows for controlled testing of security measures, ensuring robust protection against potential cyber-attacks.

Moreover, synthetic data has several other applications in cybersecurity, including threat intelligence, training security personnel, red teaming, and privacy-preserving research. It allows for realistic cyber-attack simulations and enables proactive measures to enhance security defenses. Synthetic data is crucial in strengthening cybersecurity measures, mitigating risks, and protecting sensitive information from evolving threats.

Comparison with real data Factor

Synthetic data

Real data

Data source

Generated artificially

Collected from the real world

Data collection time

Quick to generate

Time-consuming to collect

Data quality

Depends on the quality of the generator

Depends on the quality of the collection

Data bias

It can be controlled and reduced

It may contain biases from the data collection process

Data privacy

No sensitive information

May contain sensitive information

Data availability

Can be generated as needed

May be limited or difficult to obtain

12/14

Data diversity

Can be generated to reflect desired diversity

Limited by the real-world population

Data volume

Can be generated in large quantities

May be limited in quantity

Data accuracy

May not be as accurate as real data

Can be highly accurate

Data variety

May not reflect the full range of real-world variation

Reflects the full range of real-world variation

Data cost

Can be less expensive than collecting real data

Can be expensive to collect and process

Best practices for creating synthetic data Creating synthetic data requires careful consideration of various factors to ensure that the generated data is both privacy-preserving and useful for the intended purposes. The following are some of the ideal practices to keep in mind when creating synthetic data: 1. Define the purpose: Clearly define the intended use cases for the synthetic data, such as testing machine learning models or sharing data with third parties, to ensure that the data generation process aligns with these goals.

2. Choose the right technique: Select the appropriate technique for generating synthetic data, such as fully synthetic, partially synthetic, or hybrid, based on the level of privacy required and the data’s nature.

3. Identify sensitive data: Identify the sensitive data points in the original data, such as personally identifiable information (PII), and take appropriate measures to protect this information in the synthetic data.

4. Preserve statistical properties: Ensure that the synthetic data retains the statistical properties of the actual data, such as the distribution of values and relationships between features, to ensure that the generated data is representative of the original.

5. Validate the synthetic data: Validate the quality of the synthetic data by comparing it to the original data to ensure that it is precise and representative.

6. Consider the scalability: Consider the scalability of the synthetic data generation process to ensure that it can be used for large datasets or multiple use cases.

7. Document the generation process: Document the synthetic data generation process, including the techniques used, parameters selected, and assumptions made, to ensure transparency and reproducibility.

Observing these best practices can ensure that the synthetic data generated is both privacy-preserving and useful for the intended purposes, providing a valuable tool for testing machine learning models, sharing data, and other applications.

Endnote 13/14

The advantages of synthetic data are manifold. It bridges the gap between data demand and availability, empowering organizations to make data-driven decisions despite limited availability of real-world data. Synthetic data ensures privacy compliance by removing personally identifiable information and protecting individuals’ privacy. Moreover, it enables the generation of large and diverse datasets that accurately capture the complexity of real-world scenarios.

As industries continue to embrace synthetic data, it is clear that this simulated data will significantly impact data-driven decision-making. It opens up new possibilities for innovation, enabling organizations to gain valuable insights, conduct research, and make progress while upholding privacy standards. Although there are ongoing efforts to fully realize synthetic data’s potential, its current impact on various sectors is already substantial, promising to reshape the data landscape in the future.

Tap into the potential of synthetic data! Consult LeewayHertz’s team of data scientists and AI developers to unlock the full potential of artificial datasets for your business or research needs.

14/14