#Data Preparation#Synthetic Data#Self-Instruct#LLM-as-Judge#Loss Masking#Syllabus

Module 05: Datasets and Synthetic Data

Syllabus on preparing fine-tuning data — dataset formats, chat templates, loss masking, deduplication, and synthetic instruction and preference dataset generation with self-instruct and LLM-as-judge.

May 28, 2026 at 12:20 PM1 min readFollowFollow (Hindi)

Topics You Will Master

Dataset formats for fine-tuning (instruction pairs, chat format)
Chat templates (ChatML, Llama-3, Mistral) and why loss masking matters
Deduplication and filtering pipelines
Synthetic instruction and preference dataset generation
LLM-as-Judge scoring and the risks of model collapse and data poisoning
Best For

Engineers who recognise that data quality, not model choice, is the primary leverage point in fine-tuning.

Expected Outcome

The ability to design a clean, well-formatted, synthetically-augmented fine-tuning dataset while avoiding common data-quality failures.

Module Overview

This module treats data as the central lever of fine-tuning. It covers the mechanics of formatting and masking instruction data, then moves to scalable synthetic data generation and the quality-control techniques (LLM-as-Judge, deduplication) needed to avoid model collapse and poisoning.

Learning Objectives

  • Format instruction and chat datasets correctly for a target model.
  • Explain loss masking and what breaks without it.
  • Build a deduplication and filtering pipeline conceptually.
  • Generate synthetic instruction and preference data using self-instruct techniques.
  • Apply LLM-as-Judge scoring and mitigate model collapse and data poisoning.

Topics Covered

Data Preparation for Fine-Tuning

  • Dataset formats: instruction pairs, chat format
  • Chat templates: ChatML, Llama-3, Mistral
  • Loss masking — why it matters and what breaks without it
  • Deduplication and filtering pipelines

Synthetic Dataset Generation

  • Why data is the leverage point
  • The taxonomy of synthetic data
  • Instruction dataset generation: Self-Instruct and Alpaca (scaling self-instruct)
  • Preference dataset generation
  • LLM-as-Judge and LLM-as-Judge scoring
  • Tooling: distilabel, DataDreamer, Argilla
  • Risks: model collapse and data poisoning
  • End-to-end pipeline: building a domain SFT dataset

Key Concepts & Terminology

Instruction tuning data, preference pairs (chosen/rejected), label masking, near-duplicate detection, judge calibration and bias, distribution drift, model collapse.

Tools & Frameworks Referenced

distilabel, DataDreamer, Argilla, Hugging Face Datasets.

Prerequisites

Module 04 (lifecycle), familiarity with instruction-following LLMs.

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