comparing rapid sensory approaches - vtt.fi€¦ · comparing rapid sensory approaches. 2 ... §...

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Christian Dehlholm, [email protected] Consultant, Danish Technological Institute

Comparing rapid sensory approaches

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Why descriptive!

§ 1900… quality scoring and grading§ Focus on differentiating products

§ 1930… ‘Grading Foods by a Descriptive Method’§ Early descriptive whole product

system§ Minimising assessor subjectivity

§ 1930s and ‘40s…§ Selecting the right assessors§ Development of scales

§ 1950… Modern sensory evaluation§ The Flavor Profile by Cairncross &

SjostromC. Dehlholm, Nordic Workshop, 22 May 2013 Slide 3

TDS/TOS PM/Napping Sorting Pick-any/CATA

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Validity and reliability

§ Comparisons between methods and panels

Holistic!

C. Dehlholm, Nordic Workshop, 22 May 2013 Slide 5

Overall configurations compared


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Confidence – Conventional Profile

Panel A Panel B


Confidence – Global Napping

Panel A Panel B


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Confidence – Overview

9-10 h

3 h

80 min

60 min

40 min

Conventional Profile

Flash Profile

Partial Nappings

Free Multiple Sorting

Global Napping

Panel A Panel B


Confidence – Overview

9-10 h

3 h

80 min

60 min

40 min


Flash Profile

Partial Nappings


Global Napping

Panel A Panel B

-4 -2 0 2 4

-4-2

02

Dim 1 (44.94 %)

Dim

2 (2

0.59

%)

P1P2

P3P4

P5

P6P7 P8P9

Appearance

-3 -1 1 2 3 4

-3-1

12

3

Dim 1 (27.59 %)

Dim

2 (2

2.23

%)

P1

P2

P3

P4

P5

P6

P7

P8

P9

Taste

-3 -1 0 1 2 3

-20

12

34

Dim 1 (34.03 %)

Dim

2 (1

9.71

%)

P1P2

P3P4

P5

P6P7

P8P9

Mouthfeel


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Semantics – OverviewPanel P1 P2 P3 P4 P5 P6 P7 P8 P9


Flash Profile

Partial Nappings


Global NappingAppearance


Flash Profile

Partial Nappings


Global NappingTaste


Flash Profile

Partial Nappings


Global NappingMouthfeel


Conclusions 1

§ Correlation between evaluation time and reliability

§ Semantic differences

§ Free Multiple Sorting§ Comparable to projective mapping§ Provides categorical data instead of Euclidean

§ Partial Napping§ Closer relationship to conventional profiling§ Possibility to isolate single modalities -> directing perception

§ Small changes could have large effects

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Consensus vs. IndividualPanelists vs. Experts

Group no. Assessor type Evaluation type Evaluation method

G0 Trained panel Individual Conventional profiling

G1 Trained panel Individual Napping (GN/PN)

G2 Trained panel Individual Napping (GN/PN)

G3 Trained panel Consensus Napping (PN)

G4 Trained panel Consensus Napping (PN)

G5 Trained panel Consensus Attribute rating

G6 Trained panel Consensus Attribute rating

G7 Experts Consensus Attribute rating




Conclusions 2

§ Product experts less in common with references than trained panel

§ Semantic differences

§ Not recommended to compare consistency between consensus groups§ Product training could change the picture

§ Horizontal vs. vertical frame dimensions§ Geometry matters theoretically§ Rectangular geometry promotes two-dimensionality

§ Semantics improve the model

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PM on sound

News speakerLisa EkdahlRage Against the Machine


PM on sound with naïve assessors(projection strategies)


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PM on sound with naïve assessors(projection strategies)

Projection strategyNews

recordingLisa Ekdahl

Rage Against

The Machine

First

session

Second

session

Third

sessionTotal (%)

1) Linear (one-way) 45% 30% 30% 31% 36% 37% 35%

2) L or T (two-way) 12% 20% 16% 14% 18% 16% 16%

3) Dispersed 16% 13% 22% 19% 18% 13% 17%

4) Lumpy 14% 11% 10% 8% 14% 12% 12%

5) Categorical 6% 10% 7% 10% 6% 7% 8%

6) Categorical dbl. linear 6% 5% 10% 7% 4% 10% 7%

7) Other 1% 11% 6% 10% 4% 5% 6%

Total (n) 83 83 83 83 83 83 249


Conclusions 3

§ Possible for naïve assessors to use projective mapping (on sound)

§ Variations in projection strategy§ Categorisation of strategies§ One- and two-dimensional projection strategies > 50%§ Dispersed projections < 1/6

§ Might affected by§ Sample complexity§ Method experience

§ Data analytical approach does not match evaluation method§ Might explaining noise in data

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Choosing the right method!

Main considerations


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Sensory assessor types


Training

The attribute Personal constructs Aligned panel

Misaligned panels


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Conclusions 4

§ Configurations§ Methods separate in similar ways (main dimensions)§ Less time -> weaker separations

§ Semantics§ Same methods provide different descriptions§ Predetermined vocabularies -> predetermined results

§ Product approach§ Holistic approaches allow a ‘closer-to-real’ product separation§ A rapid approach is easy to administer

§ General issues§ Simpler methods might be difficult to understand (simple instructions)§ Holistic methods does not provide intensity data§ Analytical methods does minimalize conceptual reality

Future developments

Concept Scaling


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Use rapid approaches…

§ For an overview of unknown products

§ As a basis for sampling to larger experiments

§ In NPD, in idea and exploration phases

§ New semantics are wished -> Proj. mapping (Global Napping, consumers)

§ Directed semantics are wished -> Partial Napping, panel

§ Pre-known semantics are wished -> Flash Profile (with introduced vocabulary)

Thank you !

comparing rapid sensory approaches - vtt.fi€¦ · comparing rapid sensory approaches. 2 ... §...

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