How do embeddings work?

Embeddings are a technique used in natural language processing (NLP) and machine learning to represent words, sentences, or entire documents as dense vectors of numbers. These vectors capture semantic and syntactic information about the text, allowing algorithms to reason about their meanings and relationships.

Here's a high-level overview of how embeddings work:

Vector embeddings represent features or objects as coordinate points in a high-dimensional vector space. The relative positioning of these points encodes meaningful relationships between the corresponding features or objects. Similar items are placed closer together within this multidimensional space, effectively capturing their semantic similarities.

To quantify the relationships between features or objects, distances between their vector representations are calculated. Common distance metrics employed include Euclidean distance, cosine similarity, and Manhattan distance. These metrics measure how "close" or "far apart" the vectors are positioned within the vector space.

Euclidean distance calculates the straight-line distance between two points, providing a geometric interpretation of their separation. On the other hand, cosine similarity computes the cosine of the angle between two vectors. This metric is particularly useful for assessing the similarity between vectors, as it is invariant to their magnitudes. Higher cosine similarity values indicate greater similarity between the corresponding vectors.

By leveraging these distance metrics, vector embeddings enable quantitative comparisons and assessments of relationships between features or objects based on their positions within the learned vector space representation.

Let's follow the journey of a query like "things to make slime with" and see how embeddings work their magic.

Text to Numbers

At its core, an embedding represents complex data like text as a set of numbers that capture its essential features and characteristics. To create an embedding, the data is fed into a neural network that analyzes it and assigns a unique numerical representation.

For example, let's say we have the following text data:

1. "How to Make Slime with Glue and Borax"
2. "The Best Ingredients for Making Slime at Home"
3. "The Science Behind the Sticky Texture of Slime"
4. "Top 10 Slime Recipes for Kids"
5. "The History of Bubble Gum"

When these items are embedded, they might be represented as high-dimensional vectors like:

1. [0.23, 0.45, 0.67, ..., 0.89]
2. [0.27, 0.49, 0.71, ..., 0.85]
3. [0.35, 0.52, 0.63, ..., 0.78]
4. [0.19, 0.41, 0.74, ..., 0.92]
5. [0.58, 0.32, 0.47, ..., 0.61]

Each number in the vector corresponds to a specific feature or characteristic of the text.

Finding the Best Match

Now, let's say a user enters the query "things to make slime with." This query is also embedded into a numerical vector:

Query: "things to make slime with" -> [0.25, 0.47, 0.69, ..., 0.87]

To find the most relevant results, we can compare the query embedding to the results embeddings and use a similarity metric, such as cosine similarity, which is measuring the ‘closeness of the vectors’.

You can think of cosine similarity as a way to measure how similar two things are. In AI-driven search, we use it to compare vectors (like embeddings) to see how closely they match. Think of it like comparing two arrows: if they point in the same direction, they're similar. If they point in opposite directions, they're not similar.

In our example, we use cosine similarity to compare the query embedding with text embeddings. The higher the score, the more similar they are. This helps us rank results by relevance, so we can show the most relevant answers first.

Continuing with our example, the system calculates the similarity scores between the query and each text item:

1. "How to Make Slime with Glue and Borax": 0.922. 
2. "The Best Ingredients for Making Slime at Home": 0.883. 
3. "The Science Behind the Sticky Texture of Slime": 0.764. 
4. "Top 10 Slime Recipes for Kids": 0.855. 
5. "The History of Bubble Gum": 0.43

Based on these scores, the system would return the results in order of relevance:

1. "How to Make Slime with Glue and Borax" (similarity: 0.92)
2. "The Best Ingredients for Making Slime at Home" (similarity: 0.88)
3. "Top 10 Slime Recipes for Kids" (similarity: 0.85)
4. "The Science Behind the Sticky Texture of Slime" (similarity: 0.76)
5. "The History of Bubble Gum" (similarity: 0.43)

The first two results are highly related to the query, providing information on how to make slime and the best ingredients to use. The third result, "Top 10 Slime Recipes for Kids," is also closely related, offering specific slime recipes.

Interestingly, the fourth result, "The Science Behind the Sticky Texture of Slime," is somewhat unexpectedly related. While it doesn't directly answer the query, it provides background information on the scientific properties of slime, which could be useful for someone interested in making slime.

Finally, the fifth result, "The History of Bubble Gum," is not directly related to making slime. However, it was still retrieved because the embedding likely captured some shared characteristics between slime and bubble gum, such as their sticky and playful nature.

This example demonstrates how embeddings can help find highly relevant information, uncover unexpectedly related content, and even surface seemingly unrelated but potentially interesting results. The tricky part is making sure those semantic concepts and relationships stay up to date over time, as language evolves and domain-specific data changes and gets introduced.

Using Embeddings in Everyday Life

Let's start with a familiar scenario: your digital photo album at home. Each photo contains visual details like objects, colors, and scenes. Embeddings convert these details into numerical representations by feeding the images into a neural network – an AI model that analyzes patterns and assigns unique numbers to represent each photo. Similar photos are mapped closer together in a high-dimensional space, while dissimilar ones are farther apart.

With embedded photos, you can easily find specific images by providing a reference photo or text description. The system compares the embeddings, returning the most relevant results based on visual similarities captured by the numbers. This allows you to quickly locate family vacation photos or precious moments like your child's first steps.

At work, embeddings facilitate efficient document management and retrieval. Consider a large collection of research papers, articles, or reports your team needs to navigate. Creating embeddings for each document transforms the unstructured text data into numerical representations that capture semantic meaning and relationships.

With embedded documents, you can find relevant information by providing a query document or keywords. The AI system compares the embeddings, returning the most semantically similar results. This can save significant time and effort compared to manually sifting through countless documents.

Embeddings capture semantic relationships between data points, even if they don't share exact keywords or visuals. In your photo album, the AI understands visual similarities between images without identical objects or scenes. At work, you can find documents related to a topic, even if they use different terminology.

To visualize embeddings, imagine a high-dimensional space where each data point (photo or document) occupies a specific location. Similar data points cluster together, while dissimilar ones are farther apart. This spatial representation allows AI systems to efficiently navigate and retrieve relevant information based on the captured relationships.

Best Practices for Working with Embeddings

When implementing embeddings in your projects, several best practices can help optimize their effectiveness and mitigate potential pitfalls. First and foremost, it's essential to ensure that the data used for training embeddings is as diverse and representative as possible. This diversity is critical in preventing the reinforcement of existing biases within the data, which could lead to skewed or unfair outcomes when the embeddings are applied. It involves not only a broad collection of data samples but also a conscious effort to include underrepresented groups or scenarios.

Another key practice is the consistent evaluation and refinement of your embedding models. Embeddings are not static; as new data becomes available or as the context within which the embeddings operate evolves, the models may need to be retrained or tweaked. Implementing a robust pipeline for continuous evaluation against relevant metrics can help identify when an embedding’s performance begins to deteriorate, signaling the need for an update.

Dimensionality selection also plays a crucial role in the success of an embedding model. While larger dimensions can capture more information, they also require more data to train effectively and can lead to increased computational requirements. Conversely, too few dimensions may not adequately represent the complexity of the data, leading to ineffective embeddings. Experimentation and validation are necessary to find the optimal balance for your specific application.

Embeddings should also be contextualized to the specific problem at hand. For example, the embeddings used for a recommendation system in an e-commerce setting might be very different from those used for sentiment analysis in social media data. Understanding the nuances and characteristics of your application area can guide you in customizing the embedding architecture, training process, and evaluation metrics to better suit your objectives.

In a Nutshell

Embeddings have become indispensable in the toolkit of data scientists and machine learning practitioners, offering a sophisticated method to capture the essence of vast datasets in a compact, computational-friendly form. Their ability to discern and preserve intricate relationships within data makes them especially valuable across a wide range of applications, from natural language processing to personalized recommendations and beyond. As AI continues to advance, understanding embeddings will be key to unlocking their potential and driving practical innovations in our everyday lives.