Overview
ISO 8587:2006 - Sensory analysis - Methodology - Ranking defines a standardized ranking method for sensory evaluation. The standard describes how to place a series of test samples in rank order according to a single attribute, several attributes (in separate tests) or an overall impression. ISO 8587:2006 is intended to detect whether differences exist among samples (presence/ordering), not to quantify the magnitude of those differences.
Keywords: ISO 8587:2006, sensory analysis, ranking method, sensory evaluation, rank order, rank sums
Key topics and requirements
- Principle: Assessors receive simultaneously three or more coded samples in randomized order and rank them on a specified criterion (attribute or overall impression).
- Test designs:
- Complete block (preferred): each assessor ranks all samples.
- Balanced incomplete block: used when it is impracticable for assessors to rank all samples; each assessor ranks a subset so pairs/samples are balanced across assessors.
- Assessors:
- Qualification depends on purpose: selected assessors/experts for descriptive work; trained consumers for hedonic/pre‑sorting tasks.
- Typical guidance: around 12–15 selected assessors for descriptive assessment; ~60 consumers per group for hedonic preference (statistical risk dependent).
- Test conditions and sample preparation:
- Identical presentation (same vessels, quantity, temperature), randomized 3‑digit codes, masking irrelevant differences, controlled test room conditions.
- Procedure and data capture:
- One attribute per test; tied ranks to be avoided (record mean ranks if ties occur); use standardized answer forms.
- Analysis:
- Calculate rank sums to assess consistency of ordering across assessors.
- Use appropriate statistical tests (e.g., Spearman correlation for agreement) to interpret results. ISO 8587 includes guidance and annexes with practical examples.
Applications and users
ISO 8587:2006 is practical for:
- Product development and R&D teams performing pre‑sorting, comparative profiling, or order-of-preference studies.
- Sensory scientists and laboratories conducting descriptive ranking or assessing the effect of processing, ingredients, packaging, storage and dilution on perceived intensity.
- Quality assurance teams and trainer/assessor programs for assessor performance, training, and perception-threshold determination.
- Consumer researchers for straightforward hedonic ranking when ordering preferences is the objective.
Benefits: simple, resource-efficient way to detect systematic differences and order samples without requiring scale-based magnitude estimates.
Related standards