science

Quantitative Descriptive Analysis

Quantitative Descriptive Analysis is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Quantitative Descriptive Analysis rather than just read about it. In short: Developed by Tragon Corporation in 1974, Quantitative Descriptive Analysis (QDA) is a behavioral sensory evaluation approach that uses descriptive panels to measure a product's sensory characteristics. Panel members use their senses to identify perceived similarities and differences in products, and articulate those perceptions in their own words.

Key takeaways

Quantitative Descriptive Analysis belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Quantitative Descriptive Analysis to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Quantitative Descriptive Analysis from memory before moving on to harder problems.

Reference excerpt

Developed by Tragon Corporation in 1974, Quantitative Descriptive Analysis (QDA) is a behavioral sensory evaluation approach that uses descriptive panels to measure a product's sensory characteristics. Panel members use their senses to identify perceived similarities and differences in products, and articulate those perceptions in their own words. Sensory evaluation is a science that measures, analyzes, and interprets the reactions of the senses of sight, smell, sound, taste, and texture (or kinesthesis) to products. It is a people science; i.e., people are essential to obtain information about products. Tragon QDA is a registered trademark with the United States Patent and Trademark Office. The term was coined by Herbert Stone (a food scientist) and Joel L. Sidel (a psychologist)

in 1974 while at the Stanford Research Institute, (now known as SRI International (SRI)). Stone and Sidel later founded Tragon Corporation, a successful spin-off of SRI, to develop and market QDA. Originally developed within the food industry, QDA is the basis of many disciplines that involve the senses, such as clothing, cosmetics, and electronics.

Quantitative vs. qualitative research Many researchers view quantitative research design as the best approach to scientific research because it offers precise measurement and analysis. In quantitative research design the researcher will count and classify, and build statistical models to then explain what is observed. Data collected using this research approach is in the form of numbers and statistics. In the article entitled, “An Analysis of the Strengths and Limitations of Qualitative and Quantitative Research Paradigms”, author Atieno (2009), suggests, “quantitative research paradigm…is empirical in nature; it is also known as the scientific research paradigm” . This research process includes a method of deductive reasoning by use of measurable tools to collect relevant data. Quantitative research then results in precise measurements.

Key aspects of Quantitative Descriptive Analysis QDA is a behavioral approach that uses descriptive panels to measure a product's sensory characteristics. The key aspects of the methodology of Stone and Sidel are:

Subjects are consumers who are moderate to heavy users of the product. Panels are a small number (e.g., 8 - 15) of experienced subjects. Subjects are screened for sensitivity to product differences. The subjects, not the researchers, formulate the descriptions in their own terms of the sensory attributes under study. For example, subjects may be asked to rate a mineral supplement in terms of its "bitterness" rather than its "alkalinity". Data are collected from subjects without discussion among the subjects. Quantitative, not qualitative, assessments are made. Subjective descriptions such as "like", "dislike", good", or "bad" are irrelevant. Interval scales are used. Relative assessments are more important than absolute assessments. Responses are often graphically implemented (n order to avert biases associated with some numbers) and are subsequently transformed to numerical assessments, such as on a scale of 0 - 60 or 0 - 100. Products are presented for evaluation multiple times by the subjects. Replication allows for Analysis of Variation (ANOVA) to establish subject performance.

Analysis methods Analyses of QDA data include:

Analysis of Variance (ANOVA) Duncan's New Multiple Range Test (MRT) Principal Component Analysis (PCA) Pearson Product-Moment Correlation Coefficient (PPMNN or PMC)

References

Further reading Hootman, Robert C. (1992). Manual on Descriptive Analysis Testing for Sensory Evaluation. ASTM International. ISBN 978-0803117563. Stone, Herbert; Bleibaum, Rebecca; Thomas, Heather (2012). Sensory Evaluation Practices. Academic Press. ISBN 978-0123820860.

External links Campden BRI Compusense Inc. Northland Sensory Insights Archived 2014-03-26 at the Wayback Machine RedJade SEYCAM SIMS Sensory Software Tragon Corporation

Worked examples

Example 1 — a first encounter with Quantitative Descriptive Analysis

Start with the simplest possible case. Write down what Quantitative Descriptive Analysis claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Quantitative Descriptive Analysis before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Quantitative Descriptive Analysis ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Quantitative Descriptive Analysis

In research: Quantitative Descriptive Analysis appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Quantitative Descriptive Analysis in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Quantitative Descriptive Analysis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Product testing, so understanding it makes those chapters shorter.
In everyday life: Look for Quantitative Descriptive Analysis outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Quantitative Descriptive Analysis in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Quantitative Descriptive Analysis means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Quantitative Descriptive Analysis out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Quantitative Descriptive Analysis in simple terms?

Why does Quantitative Descriptive Analysis matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Quantitative Descriptive Analysis?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Quantitative Descriptive Analysis.