Update README.md

README.md

@@ -42,6 +42,47 @@ PENS ensures user privacy by de-linking user data from the production system and
 - **Paper:** [Link to the PENS Paper](#citation)
 - **Related Works:** [Available Related Works on PENS](#more-information)
 
+## Dataset Structure
+
+<!-- This section provides a description of the dataset fields, and additional information about the dataset structure such as criteria used to create the splits, relationships between data points, etc. -->
+
+PENS consists of two main components: the training set and the test set.
+
+- **Training Set:**
+  - **News Articles:** ~113,762 entries
+    - **Fields:**
+      - `News ID`: Unique identifier for each news article (e.g., N10000).
+      - `Category`: One of 15 predefined categories (e.g., sports).
+      - `Topic`: Specific topic within the category (e.g., soccer).
+      - `Headline`: The title of the news article.
+      - `News body`: The full content of the news article.
+      - `Title entity`: JSON mapping between phrases in the title and their corresponding entities in WikiData.
+      - `Entity content`: Detailed information about each entity from WikiData.
+  - **Impression Logs:** 500,000 entries
+    - **Fields:**
+      - `UserID`: Anonymous identifier for the user (e.g., U335175).
+      - `ClicknewsID`: Space-separated list of historically clicked news IDs.
+      - `Dwelltime`: Space-separated list of browsing durations for each clicked news.
+      - `Exposure_time`: Space-separated list of exposure times for historical clicked news (separated by `#TAB#`).
+      - `Pos`: Space-separated list of clicked news IDs in the current impression.
+      - `Neg`: Space-separated list of unclicked news IDs in the current impression.
+      - `Start`: Start time of the impression (e.g., 7/3/2019 6:43:49 AM).
+      - `End`: End time of the impression (e.g., 7/3/2019 7:06:06 AM).
+      - `Dwelltime_pos`: Space-separated list of browsing durations for clicked news in the current impression.
+
+- **Validation Set:**
+  - Structured similarly to the training set, used for validating model performance during training.
+
+- **Test Set:**
+  - **Personalized Headlines:** >100,000 entries
+    - **Fields:**
+      - `userid`: Unique identifier for each of the 103 test users (e.g., NT1).
+      - `clicknewsID`: Comma-separated list of historically clicked news IDs from the first stage.
+      - `posnewID`: Comma-separated list of exhibited news IDs in the second stage.
+      - `rewrite_titles`: Space-separated list of manually written personalized headlines (separated by `#TAB#`).
+
+The dataset is structured to facilitate the mapping between user behaviors and personalized headline generation.
+
 ## Uses
 
 ### Direct Use