RUŌOD Lab

Level 6 · Complete Perfume Creation

Compare Two Versions Blind: Study Guide

Read our guide to comparing formulas, then pair a line-by-line difference table with a blind smelling test to find out whether a change actually shows.

Intermediate 15 min study By the RUŌOD Lab team Updated

In short

You can compare two versions in two ways, on paper and by nose, and they answer different questions. The reference guide explains the paper method. This study guide pairs it with a blind test, because a difference in the numbers may not be a difference anyone can smell, and the reverse can also happen.

What you will learn

  • Compare two versions on paper and blind on strips
  • Decide whether a formula difference is perceptible

Before this lesson: Composition Mistakes: Study Guide and Self-Audit

What to look for as you read

  • How to line up two formulas with different materials.
  • What counts as a large difference.
  • Why the guide considers proportional change.

Practical exercise: Paper and nose, on one pair

About 45 minutes · You will have: a difference table for two versions, plus blind trial results

  1. Choose two versions of a composition. Normalize both on pure active, and draw a difference table.
  2. Predict whether you could tell them apart, and at what time point.
  3. Run six blind triangle trials at one early and one later time point.
  4. Write what the numbers said, what your nose said, and whether they agreed.

You have done this well if your conclusion uses both, and it takes the chance level into account.

Knowledge check

1. Your table shows a 20% change in one line, but you cannot detect it blind. What follows?
Show the answer

Under these conditions that change had no perceptible effect for you. It may be a low-impact line or a low share. Another nose or another stage in development may differ.

2. Why compare on a normalized, pure-active basis?
Show the answer

So solvent and total differences do not disguise the real change. That makes the difference table reflect the composition.

3. You prefer the version you know is newer. What should you suspect?
Show the answer

Expectation bias. Most people favor what they just worked on, which is why you test blind.

Further reading and materials

Written and reviewed by the RUŌOD Lab team. This is general education, not legal, regulatory, medical or safety advice. Example dilutions and exercises are for learning, are not validated products, and have not been safety-assessed. Completing a lesson confers no qualification. How we check these lessons.