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@mightyhorst
Created April 10, 2024 08:06
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@learn-d2l-ai
I see where the confusion might have come from, especially with the introduction of a query value "2" without a clear explanation. Let's clarify the concept of a query in the context of the attention mechanism and adjust the example for better understanding.
In the context of attention mechanisms, a **query** (\(\mathbf{q}\)) represents the current item or piece of information the model is focusing on or trying to relate to other pieces of information. The **keys** (\(\mathbf{k}_i\)) represent aspects or features of other items in a dataset, and the **values** (\(\mathbf{v}_i\)) represent the content or information of those items. The goal of the attention mechanism is to determine how relevant each item (key-value pair) in the dataset is to the query and to produce a weighted combination of these items' values based on their relevance.
Let's correct and simplify the example without introducing arbitrary numbers for the query:
Imagine we have a dataset of items, each with a key (\(\mathbf{k}_i\)) and a value (\(\mathbf{v}_i\)). We want to find out how relevant each item is to a given query (\(\mathbf{q}\)).
For simplicity, let's assume:
- Our query (\(\mathbf{q}\)) is a specific feature or characteristic we are interested in.
- We have 3 items in our dataset, each with a key representing its features and a value representing the information or content of that item.
Here's a conceptual step-by-step process without specific numbers, focusing on the mechanism:
1. **Calculate Similarity Scores**: For each item in the dataset, calculate a similarity score between the query (\(\mathbf{q}\)) and the item's key (\(\mathbf{k}_i\)). This score (\(\alpha(\mathbf{q}, \mathbf{k}_i)\)) indicates how relevant or similar the item is to the query.
2. **Compute Weighted Sum of Values**: Use the similarity scores as weights to compute a weighted sum of the items' values. This results in a single value that represents a combination of the dataset's information, prioritized by relevance to the query.
**Conceptual Example**:
- Suppose we're interested in how relevant each book in a library is to the topic of "science fiction" (our query).
- Each book has a key (e.g., its summary or keywords) and a value (e.g., its title).
- We calculate similarity scores based on how closely each book's summary matches the "science fiction" theme.
- Books with summaries more closely related to "science fiction" get higher scores.
- We then combine the titles (values) of all books, weighted by their scores, to get a "summary" of science fiction books in the library.
This example abstracts away the specific calculations and numerical values to focus on the attention mechanism's purpose: to weigh and combine information based on relevance to a specific query or interest point.
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