docs: add condition-3-zh-5k to README (schema, configs, usage)

README.md

@@ -231,15 +231,18 @@ Keyword-swapped variants are produced using [Legesher](https://github.com/legesh
 
 ## Available Configs
 
-| Config           | Condition             | Language | Description                                                                                      |
-| ---------------- | --------------------- | -------- | ------------------------------------------------------------------------------------------------ |
-| `condition-1-en` | Condition 1 (control) | English  | Unmodified filtered Python from The Stack Dedup                                                  |
-| `condition-2-ur` | Condition 2           | Urdu     | Keyword-swapped Python -- 37 keywords, 72 builtins, 66 exceptions translated via Legesher v0.7.3 |
-| `condition-2-zh` | Condition 2           | Chinese  | Keyword-swapped Python -- same transpilation method                                              |
-| `condition-2-es` | Condition 2           | Spanish  | Keyword-swapped Python -- same transpilation method                                              |
+| Config                | Condition             | Language | Description                                                                                      |
+| --------------------- | --------------------- | -------- | ------------------------------------------------------------------------------------------------ |
+| `condition-1-en`      | Condition 1 (control) | English  | Unmodified filtered Python from The Stack Dedup                                                  |
+| `condition-2-ur`      | Condition 2           | Urdu     | Keyword-swapped Python -- 37 keywords, 72 builtins, 66 exceptions translated via Legesher v0.7.3 |
+| `condition-2-zh`      | Condition 2           | Chinese  | Keyword-swapped Python -- same transpilation method                                              |
+| `condition-2-es`      | Condition 2           | Spanish  | Keyword-swapped Python -- same transpilation method                                              |
+| `condition-3-zh-5k`   | Condition 3           | Chinese  | Blended: 3,486 native Chinese code + 1,514 transpiled Python (see Condition 3 section below)     |
 
 ## Schema
 
+### Conditions 1--2
+
 | Column        | Type   | Description                                                                                                                                          |
 | ------------- | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `code`        | string | Python source code. For condition-2 configs, this is the transpiled (keyword-swapped) version. For condition-1, this is the original English source. |
@@ -249,16 +252,31 @@ Keyword-swapped variants are produced using [Legesher](https://github.com/legesh
 | `license`     | string | SPDX license identifier for the source file.                                                                                                         |
 | `token_count` | int64  | Token count computed using the CohereLabs/tiny-aya-base tokenizer.                                                                                   |
 
+### Condition 3
+
+Condition 3 blends native Chinese code with transpiled code and adds a `source_type` column to distinguish them. `code_en` is populated for transpiled rows (keeping them in sync with conditions 1--2) but null for native code rows, which have no English equivalent.
+
+| Column        | Type        | Description                                                                        |
+| ------------- | ----------- | ---------------------------------------------------------------------------------- |
+| `file_path`   | string      | File identifier (native filename or transpiled file path)                          |
+| `code`        | string      | The code content (native or transpiled)                                            |
+| `code_en`     | string/null | English original -- populated for transpiled rows, null for native code rows       |
+| `language`    | string      | ISO 639-1 language code (`zh`)                                                     |
+| `license`     | string      | Source license (SPDX identifier, `UNKNOWN`, or `varies`)                           |
+| `token_count` | int64       | Token count computed using the CohereLabs/tiny-aya-base tokenizer                  |
+| `source_type` | string      | `"native"` (natively Chinese-authored) or `"transpiled"` (keyword-swapped English) |
+
 ## Experimental Conditions
 
 The Language Decoded experiment uses a ladder of six conditions to isolate the mechanism behind code's reasoning benefit. This dataset currently provides data for conditions 1 and 2:
 
-| Condition       | Name                 | Purpose                                                                    |
-| --------------- | -------------------- | -------------------------------------------------------------------------- |
-| Baseline        | No fine-tuning       | Establishes the performance floor                                          |
-| Condition 1     | English code         | Tests whether code fine-tuning helps at all (replicates Aryabumi et al.)   |
-| Condition 2     | Keyword-swapped code | Tests whether the _language_ of keywords matters for the reasoning benefit |
-| Conditions 3--6 | (planned)            | Additional controls not yet included in this dataset                       |
+| Condition       | Name                 | Purpose                                                                                   |
+| --------------- | -------------------- | ----------------------------------------------------------------------------------------- |
+| Baseline        | No fine-tuning       | Establishes the performance floor                                                         |
+| Condition 1     | English code         | Tests whether code fine-tuning helps at all (replicates Aryabumi et al.)                  |
+| Condition 2     | Keyword-swapped code | Tests whether the _language_ of keywords matters for the reasoning benefit                |
+| Condition 3     | Mixed native sources | Tests whether diverse native-language code adds value beyond keyword swapping              |
+| Conditions 4--6 | (planned)            | Additional controls not yet included in this dataset                                      |
 
 ## Usage
 
@@ -273,9 +291,15 @@ ds = load_dataset("legesher/language-decoded-data", "condition-2-ur")
 ds = load_dataset("legesher/language-decoded-data", "condition-2-zh")
 ds = load_dataset("legesher/language-decoded-data", "condition-2-es")
 
+# Load blended native + transpiled (condition 3)
+ds = load_dataset("legesher/language-decoded-data", "condition-3-zh-5k")
+
 # Access splits
 train = ds["train"]
 val = ds["validation"]
+
+# Filter condition-3 by source type
+native_only = train.filter(lambda x: x["source_type"] == "native")
 ```
 
 ## Technical Details