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---
license: apache-2.0
base_model: Qwen/Qwen3.5-9B
library_name: transformers
pipeline_tag: text-generation
language:
- en
tags:
- ielts
- education
- content-generation
---
# PrepareBuddy IELTS-9B (Qwen3.5) β€” the most factually accurate
The largest model in the family. A fine-tune of [Qwen3.5-9B](https://huggingface.co/Qwen/Qwen3.5-9B)
(Apache-2.0) on PrepareBuddy's curated IELTS content. It generates IELTS practice across **all four sections.**
> **A content generator, not an assessment tool.** It writes passages, transcripts, tasks,
> questions and answer keys. It does **not** score student work. A **fine-tune** of Qwen3.5-9B β€”
> **not** a from-scratch foundation model.
## Where the 9B fits (the honest study result)
Part of our 2B/4B/9B study. Two things the size buys β€” and one it doesn't:
- βœ… **Best world-knowledge / facts:** from-scratch passages get names, dates and places right more
often than the smaller models (e.g. correct "Central Asia" where a 2B wrote the wrong region).
- βœ… **100% completion answers verbatim-in-passage.**
- ❗ **Size did *not* buy better verdict reasoning** β€” fine-tuning was *flat* (base 79% β†’ ft 77%), and a
fine-tuned 2B matched it on verdicts. So pick the 9B for **fact-heavy from-scratch generation**, not
because it reasons better about verdicts.
![Our smallest model matched our biggest β€” size didn't buy verdict reasoning](data_beats_size.png)
Full numbers: [technical report](https://huggingface.co/preparebuddy/ielts-qwen3.5).
## Where it fits best (real-world use cases)
Reach for the **9B** when **factual fidelity** is the priority and you have a **GPU**:
- **Fact-heavy from-scratch passages** β€” science, history, geography: it gets names/dates/places right most often.
- **A content factory on a GPU server** β€” bulk-generate a question bank where passage accuracy matters most.
- **The top-quality tier** behind a paid product, paired with grounding + verification.
- **Sentence/summary completion** β€” 100% in-passage answers.
**Not the best pick for** laptops/edge or cost-sensitive serving (β†’ **2B/4B**), or if you expect better *verdict reasoning* β€” size didn't buy that (a fine-tuned 2B matched it).
## Pros & cons
| βœ… Pros | ⚠️ Cons |
|---|---|
| **Best facts** in the family; **100% completion** | **Heaviest** β€” ~18 GB VRAM bf16 (quantise to ~5–6 GB) |
| Strong Writing / Speaking / Listening | MCQ answer-position skews to "B" β€” fix at serving |
| Most reliable from-scratch passages | Verdict reasoning **no better** than the 2B (~8% easy / β‰ˆ25% varied) |
| Apache-2.0; the quality ceiling of the set | Best on a GPU/server, **not a laptop** |
## Links
- 🧠 **Models:** [ielts-2b](https://huggingface.co/preparebuddy/ielts-2b) · [ielts-4b](https://huggingface.co/preparebuddy/ielts-4b) · **[ielts-9b](https://huggingface.co/preparebuddy/ielts-9b)**
- πŸ’» **Apple Silicon / LM Studio (MLX):** [ielts-2b-mlx](https://huggingface.co/preparebuddy/ielts-2b-mlx) Β· [ielts-4b-mlx](https://huggingface.co/preparebuddy/ielts-4b-mlx)
- 🌐 **Try the live demo:** [Hugging Face Space](https://huggingface.co/spaces/preparebuddy/ielts-demo)
- πŸ“„ **Full technical report & findings:** [ielts-qwen3.5](https://huggingface.co/preparebuddy/ielts-qwen3.5)
## What it generates
| Section | Types | Output |
|---|---|---|
| **Reading** | TFNG, YNNG, MCQ, Sentence/Summary Completion, Matching, Long-form | passage + questions + answer key with justifications |
| **Writing** | Task 1 (chart), Task 2 (essay) | task prompt + word limit + timing (+ chart data for T1) |
| **Listening** | dialogue/monologue | transcript + questions + answer key (text for downstream TTS) |
| **Speaking** | Part 1, 2, 3 | examiner question / cue card + model answer |
## Prompt format (not a chat model β€” use the tag prefix)
```
<TEST=IELTS><SECTION=READING><TYPE=TFNG><DIFF=medium><TOPIC=ocean currents> Generate a short passage with 4 True/False/Not Given statements and an answer key.
```
- `SECTION` = `READING | WRITING | LISTENING | SPEAKING`
- `TYPE` (Reading) = `TFNG | YNNG | MCQ | MCQ_MULTI | SENTENCE_COMPLETION | SUMMARY_COMPLETION | MATCHING_HEADINGS | MATCHING_FEATURES | MATCHING_ENDINGS | LONGFORM`; (Writing) `TASK1 | TASK2`; (Speaking) `PART1 | PART2 | PART3`; (Listening) `LISTENING`
- `DIFF` = `easy | medium | hard`
- **Serve with `enable_thinking=False`** β€” for this task, reasoning mode *lowers* verdict accuracy.
## Examples (the family's shared output format; answer keys verified)
> These illustrate the **format all three models produce** β€” the **9B generates it with the highest
> factual accuracy and 100% completion grounding**. Reading examples use the **recommended grounded
> approach** (generate against a real passage), so every answer key here was checked against its passage.
> (The 9B needs a GPU to run β€” ~18 GB in bf16 β€” so we show the shared verified format rather than a laptop generation.)
### Writing β€” Task 2 (temp 0.7)
**Input**
```
<TEST=IELTS><SECTION=WRITING><TYPE=TASK2><DIFF=medium><TOPIC=whether university education should be free> Generate an IELTS Academic Writing Task 2 question with word limit and timing.
```
**Output**
```
TASK:
Some people believe that university education should be free for all students who wish to
pursue a degree, while others think this would result in very high costs.
To what extent do you agree or disagree?
WORD LIMIT: 250 words TIME: 40 minutes
```
### Reading β€” True/False/Not Given (grounded, temp 0.3 β€” keys verified)
**Input**
```
<TEST=IELTS><SECTION=READING><TYPE=TFNG><DIFF=medium><TOPIC=coral reefs> Using ONLY the passage below, write True/False/Not Given statements with an answer key. Do not write a new passage.
PASSAGE: Coral reefs … are built by tiny animals called polyps, which secrete calcium carbonate to form hard skeletons. Reefs grow only in warm, shallow, sunlit water … The Great Barrier Reef, off Australia, is the largest reef system in the world.
```
**Output**
```
QUESTIONS:
1. Coral reefs are built by tiny animals called polyps that secrete calcium carbonate.
2. Coral reefs grow in cold, deep water because the polyps depend on algae for food.
3. The Great Barrier Reef is the largest reef system on Earth.
ANSWER KEY:
1. TRUE β€” "built by tiny animals called polyps, which secrete calcium carbonate".
2. FALSE β€” the passage says reefs "grow only in warm, shallow, sunlit water", not cold deep water.
3. TRUE β€” "The Great Barrier Reef … is the largest reef system in the world".
```
### Reading β€” Multiple Choice (grounded, temp 0.3 β€” key verified)
**Output**
```
QUESTION β€” Choose the correct letter, A, B, C or D.
Why do coral polyps depend on algae living in their tissues?
A. The algae provide calcium carbonate to build the skeleton.
B. Algae help polyps survive in cold, deep water.
C. The algae supply food to the polyps through photosynthesis.
D. Algae protect polyps from bleaching.
ANSWER KEY:
1. C β€” the passage states polyps "depend on algae living in their tissues for food"; the other options are not stated.
```
*(⚠️ MCQ correct-answer letter skews toward "B" on the 9B β€” spread answer positions at serving, or only publish pre-checked MCQ.)*
### Reading β€” Sentence Completion (grounded, temp 0.3 β€” 9B answers 100% in-passage)
**Output**
```
QUESTIONS β€” Complete each sentence with ONE word from the passage.
1. Reefs grow only in warm, shallow water because the polyps depend on algae for _____. β†’ food
2. When water becomes too warm, the polyps expel the algae and turn white β€” a process known as _____. β†’ bleaching
```
## Supported types per section β€” and how to prompt each
| Section Β· Type | Prompt `<TYPE=…>` | Temp | What you get |
|---|---|---|---|
| Reading Β· True/False/Not Given | `TFNG` | 0.3 | passage + statements + key |
| Reading Β· Yes/No/Not Given | `YNNG` | 0.3 | opinion passage + statements + key |
| Reading Β· Multiple choice | `MCQ` / `MCQ_MULTI` | 0.3 | passage + A–D question(s) + key *(watch the "B" skew)* |
| Reading Β· Sentence/Summary completion | `SENTENCE_COMPLETION` / `SUMMARY_COMPLETION` | 0.3 | gap items + key *(9B: 100% in-passage)* |
| Reading Β· Matching | `MATCHING_*` | 0.5 | matching task + key *(experimental)* |
| Reading Β· Long-form | `LONGFORM` | 0.6 | ~600-word passage + mixed questions + key |
| Writing Β· Task 1 / Task 2 | `TASK1` / `TASK2` | 0.7 | task + word limit + timing |
| Speaking Β· Part 1/2/3 | `PART1` / `PART2` / `PART3` | 0.7 | examiner question / cue card + model answer |
| Listening | `LISTENING` | 0.7 | transcript + questions + key |
**Tip β€” for dependable Reading keys, generate *grounded*:** prepend a real passage and add *"Using
ONLY the passage below … Do not write a new passage."*
## Generating a full exam section (one passage β†’ all question types)
Generate **one passage**, then each question type **against it**:
1. `<…TYPE=LONGFORM…> Write ONLY a ~600-word IELTS reading passage. No questions.`
2. For each type: `Using ONLY the passage below, write 5 TFNG statements with an answer key. Do not write a new passage.\nPASSAGE:\n<passage>`
3. Concatenate β†’ a real-exam-style section. The 9B's strong facts make its from-scratch passages the most reliable base. (The [demo Space](https://huggingface.co/spaces/preparebuddy/ielts-demo) does this.)
## Usage (transformers)
```python
import torch
from transformers import AutoModelForCausalLM, AutoTokenizer
repo = "preparebuddy/ielts-9b"
tok = AutoTokenizer.from_pretrained(repo)
# ~18 GB in bf16 (24 GB+ GPU). For smaller GPUs, load 4-bit (~5–6 GB):
model = AutoModelForCausalLM.from_pretrained(repo, dtype=torch.bfloat16, device_map="auto").eval()
SYSTEM = ("You generate authentic IELTS Academic practice content across reading, writing, "
"listening, and speaking. Produce passages, transcripts, tasks, questions, and answer "
"keys or model answers as appropriate to the section. Use IELTS-style register: "
"academic, neutral, factually plausible. This is content generation, not assessment.")
user = "<TEST=IELTS><SECTION=READING><TYPE=TFNG><DIFF=medium><TOPIC=solar power> Generate a short passage with 4 True/False/Not Given statements and an answer key."
inp = tok.apply_chat_template([{"role":"system","content":SYSTEM},{"role":"user","content":user}],
add_generation_prompt=True, enable_thinking=False, return_tensors="pt", return_dict=True).to(model.device)
out = model.generate(**inp, max_new_tokens=900, do_sample=True, temperature=0.3, top_p=0.9)
print(tok.decode(out[0][inp["input_ids"].shape[1]:], skip_special_tokens=True))
```
**Settings:** temp **0.3** for verdicts (TFNG/YNNG/MCQ), **0.7** for passages/writing/speaking; `top_p 0.9`; one SECTION+TYPE per call. **VRAM:** ~18 GB bf16; quantise (`load_in_4bit=True`) to ~5–6 GB for normal GPUs. The 9B's home is **code/server or a GPU Space** rather than a laptop.
## Recommended architecture for reliable output (important)
The 9B is a strong **drafter** with the family's best facts. For dependable answer keys, run it as a system:
1. **Ground** β€” generate against a *real* passage (the 9B's strong facts already make from-scratch passages reliable, but grounding removes residual risk).
2. **Verify** β€” re-check each answer key with an independent judge (a trained 2B is a cheap, effective verifier) and flag disagreements.
3. **Review/regenerate** the small flagged minority.
![It's a smart drafter β€” and we double-check its work](honest_system.png)
*Measured end-to-end: raw grounded generation β‰ˆ **75%** β†’ β‰ˆ **85–90%** with this verify loop.*
## Strengths & honest limits (9B)
- βœ… **Best facts** in the family; **100% completion**; strong Writing/Speaking/Listening; **0 non-English-token leak**.
- ⚠️ **MCQ answer-position skews to "B"** (in our sample the correct answer was B 7/7) β€” spread the position at serving, or only publish pre-checked MCQ.
- ⚠️ **Verdict reasoning is no better than the smaller models** β€” ~8% logic slips on easy items (β‰ˆ25% on varied from-scratch); use grounding + verification.
- ⚠️ **Heaviest to run** β€” ~18 GB VRAM (bf16); best on a GPU/server, not a laptop.
- Listening/Speaking output is **text** (for downstream TTS); no audio. Not an assessment tool.
## Training
LoRA fine-tune of Qwen3.5-9B (bf16; r16/Ξ±32; completion-only loss; `enable_thinking=False`; 2 epochs, lr 1e-4), trained on an **NVIDIA L40S (48 GB)** cloud GPU, on **1,438** curated + balanced examples (β‰ˆβ…“ NOT GIVEN in verdict types). **Dataset not released (proprietary).** Full method, hardware and results: [technical report](https://huggingface.co/preparebuddy/ielts-qwen3.5).
## License
Apache-2.0, inheriting from Qwen3.5-9B. Free to use, modify, distribute (incl. commercially); retain attribution to the base model and PrepareBuddy.
---
## The 2B / 4B / 9B family β€” pick the right one
![What we built, by the numbers](by_the_numbers.png)
| | [ielts-2b](https://huggingface.co/preparebuddy/ielts-2b) | [ielts-4b](https://huggingface.co/preparebuddy/ielts-4b) ⭐ | [ielts-9b](https://huggingface.co/preparebuddy/ielts-9b) |
|---|---|---|---|
| Best for | cheapest; best verdict judge/verifier | balanced general use | **best facts (from scratch)** |
| Verdict accuracy (fine-tuned)ΒΉ | **80%** | 74% | 77% |
| Completion answers in-passage | ⚠️ 37% | βœ… 100% | βœ… 100% |
| Facts in from-scratch passages | weakest | good | βœ… **best** |
| MCQ answer-position | ok | ok | ⚠️ skews "B" |
| Size (bf16) | ~5 GB | ~9 GB | **~18 GB** |
| Use with grounding | strongly | recommended | recommended |
ΒΉ greedy, 101-item held-out gold. *Fine-tuning's benefit is inversely proportional to base capability β€” it transformed the 2B (+40) and was flat on the 4B/9B.* Full method + findings + tables: **[technical report](https://huggingface.co/preparebuddy/ielts-qwen3.5)**.
## Getting better results: grounding + the re-checking loop (the biggest quality lever)
**1. Ground** β€” generate against a *real* passage so facts come from the source:
```
Using ONLY the passage below, write 4 True/False/Not Given statements with an answer key. Do NOT write a new passage.
PASSAGE: <your real passage>
```
**2. Re-check (verify)** β€” independently re-judge each answer key, flag disagreements:
```python
for statement in generated_statements:
verdict = judge(model, passage, statement) # TRUE / FALSE / NOT GIVEN
if verdict != generated_key[statement]:
flag_for_review_or_regenerate(statement) # the verifier catches ~75-80% of errors
```
A **trained 2B catches ~75–80%** of verdict errors as a verifier (cheap); any 4B+ works too.
**3. Review / regenerate** the flagged minority. *Measured:* β‰ˆ **75%** raw β†’ β‰ˆ **85–90%** with this loop.
## Prompt tips
- **Always use the tag prefix** `<TEST=IELTS><SECTION=…><TYPE=…><DIFF=…><TOPIC=…>` β€” it's not a chat model.
- **Temperature:** 0.3 for verdicts, 0.7 for passages/writing/speaking; top_p 0.9.
- **`enable_thinking=False`** β€” reasoning mode *lowers* verdict accuracy.
- **One SECTION+TYPE per call;** build a full section by generating each type against one shared passage.