Statistical Analysis System (SAS) Software

The Statistical Analysis System (SAS) software is a computer program that allows its users to perform powerful data analysis on data obtained from research experiments in any field. SAS has become an invaluable tool used currently by students, professors, and within industry to perform data analysis. Some schools have classes dedicated to learning SAS so that students are prepared to analyze their own data once they have graduated and become members of industry or go on to pursue further academic research¹.
SAS is a very powerful tool within sensory science. Using SAS you are able to analyze sensory data to find out if the variables being tested in products statistically differ from each other. SAS has no maximum for data entry so difference testing can be computed for projects with very large sample sizes. SAS also allows you to perform data entry and analysis on complicated research models, including nested models¹.
SAS has its own programming language with different sets of commands that allow its users a vast number of ways to interpret their data. Some of the more basic functions that SAS can perform include: Uncorrected Sums of Squares, Variance, Standard Deviation, 95% Confidence Intervals, and t-tests among others. Besides these basic functions SAS also allows you to do more complicated difference testing which includes: Analysis of Variance for simple and complex models, Paired t-Test, Expectations of Mean Squares, F Ratios, Duncan’s New Multiple Range Test, Dunnett’s One-tailed and Two-tailed tests, Tukey’s Honest Significant Difference (HSD) Test, Fisher’s Protected Least Significant Difference (LSD) Test, Mean Separations Within Interactions, and Orthogonal Polynomial Comparisons among others. SAS also has the ability to perform regression analysis on any order polynomial and has the ability to graph these regression analyses as well as graph any other data¹. UCLA also has a great website for getting help with SAS which can be found at http://www.ats.ucla.edu/stat/sas/.

References

¹ SAS Institute, 2000. SAS SQL Procedure User’s Guide, Version 8, SAS.

Style of wiki articles

When creating a new wiki article, please following the style guidelines described below. Having a consistent style is very important for readability.

Article Page Name

First and foremost, please choose an article page name fairly carefully, as this will be the system identifier of the article. The page name should be as short as possible without unduly sacrificing specificity. For example, an article on palate cleansing could be named “palate cleansing” if it was a general treatment of the topic, but if it was specific to spicy foods and there was already an article that dealt with, say, lingering sweeteners, you may then want to include “spicy” in the page name.

Also note that when a wiki article refers to another wiki article, it will do so using the page name as the text of the (internal) hyperlink. Hence, an article page name should be something that can be logically and readily used in a sentence.

Assigning a Category

To help organize the wiki, articles are assigned to categories. For example, this article was put under the “help” category. There are also several articles that are under “basic taste.” If the article can be placed within an existing category, it should be. But it may certainly happen that a new category is the first of its kind.

There is a special syntax used to assign an article to a category. The word “Category” and the name of the category must be separated by a colon and enclosed with a set of matching double brackets. Note that there are no spaces either before or after the colon character. For example, this article was categorized by using the following as the first line:

Formatting

Please set the name of the article, which can be longer than the article page name, in larger text using a heading style of “h1”. To do this, simply type “h1” followed by a period, and then a single space before the title text.

Internal references (hyperlinks)

Material already in the wiki should never be copied and pasted into another article, but, instead, it should simply be referenced. To reference another page within the wiki simply enclose the article name within matching double brackets. For example, suppose we wanted to refer back the general, main, help page. In the article, such a reference would look like this: help. When editing, this reference would be entered as follows:

External references (hyperlinks)

When an article needs to reference a web page external to the wiki — that is, to provide a standard hyperlink — the syntax for that is somewhat more involved. Suppose that you wanted to reference wikipedia’s article on wiki’s and have the hyperlink formatted as: what is a wiki?. This would be accomplished as follows:

"what is a wiki?":http://en.wikipedia.org/wiki/Wiki

Notice that the hyperlink text is first and enclosed in double quotes, followed by a colon, and then finally the full URL.

Footnotes

Whenever possible, if statements are made that are not common knowledge, or a quote is used, a reference needs to be given. In order to avoid hard-to-read, cluttered text, references can be included through the use of footnotes. A footnote can be included by just enclosing its sequential number in matching single brackets. Later, at the end of the article, the footnote text is specified with the “fn” command followed by a number, immediately next to the text.

For example, suppose one made the following quote:

You can, for example, never foretell what any one man will do, but you can say with precision what an average number will be up to¹.

The footnote reference was entered as follows:

... average number will be up to[1].

Later, the actually footnote might look like:

¹ Sherlock Holmes in “The Sign of Four,” 1890.

And was entered as follows:

fn1. Sherlock Holmes in “The Sign of Four,” 1890.

If a sentence has multiple footnotes, the footnotes should be separated with super-scripted commas as follows:

...end of sentence.[5][^,^][6]

and would be formatted as follows:

…end of sentence.^5,6

Images, Graphics and Equations

If needed by the article, a graphics image (whether a chart, equation, etc.) can be used by first uploading it to the wiki images area using the “File Upload” menu option. The system guides you through the process, and ends by displaying the appropriate way to reference the image in the article. When using images, please be sure to save the file using the smallest size reasonable.

Article Discussions

Because the society site has forums built-in, any discussions of article content should be done using the article forum. If an article does not have a discussion ongoing, there will be a menu tab that says “start a discussion”, and if there is a discussion already started, it will say “discuss article”.

Consumers’ sensory acceptance of food products is complex and interdisciplinary, encompassing all aspects of food science, marketing, nutrition, psychology and hospitality¹. Acceptance depends on many things: sensory attributes, consumer physiological, behavioral and cognitive factors²³ and the ability to understand these variables is important.
Research shows that cues: intrinsic and extrinsic, help to study sensory acceptance. Intrinsic characteristics, including taste, aroma and color often cannot be altered without changing the nature of the product and these characteristics are usually specific to the product. Extrinsic characteristics include brand name, price, advertisement, labeling and country of origin⁴. The U.S. has become interested in also knowing about quality attributes such as food safety, animal welfare and organic production⁵.
No matter which cues are being tested, in order to collect as much information as possible from consumers, it is necessary to consider the amount of information provided in the study. Blind testing is defined by Moskowitz⁶ as evaluating products without the benefit of product identification. Branded testing is evaluating products with some product knowledge given to the consumer. Moskowitz⁶ said that when a consumer assigns an attribute rating to a product without knowledge of product identification, ratings may dramatically change when they are given the identification.
According to Siret and Issanchou⁷, labeling usually is considered to have a positive effect on overall acceptability. Bower, Saadat and Whitten⁸ evaluated 70 consumers and looked at the effect of liking, information, and consumer characteristics on purchase intent and willingness to pay more for two fat spreads with proven health benefits. Unlabeled testing showed significant differences in overall liking of the spreads and purchase intent. Labeled testing also showed a significant difference in overall liking when information was provided. Results showed that purchase intent was significantly affected by label information, such as price and nutritional benefit. The significant difference in liking between the two spreads contributed to the intention to buy, with higher purchase intent for the product which was liked more. This study indicates that consumers are aware of the label information on products.
Other times labeling could have a negative effect on consumer acceptability. Cues often are communicated by the media to influence consumers’ liking of different products⁸. Berger and Mitchell⁹ showed that advertising can influence more than just the evaluation dimensions of attitudes. It can influence how easily an evaluation is accessed from memory, how confidently it is held and how likely it is to influence subsequent behavior. For example, Siret and Issanchou⁷ found that non-traditional information provided on ground pâtés from France created low expectations and had a negative effect on visual evaluations. Levis and Chambers¹⁰ showed that labeling products as low salt reduced scores for low salt potato chips, which they associated with negative perceptions about more healthful products at the time. When consumers have a negative acceptance of a product it can lead them not purchasing the product. Deliza and MacFie¹¹ stated that how advertisements are presented, as well as the price and appearance, can appeal to consumers differently.
If testing of consumer acceptance is the study objective, then considering the effect of labeling will be important to successful results. It is widely known that sensory properties are important to determine consumer liking of products and paying attention to the effect of different types of labeling could enhance knowledge in the product category. Incorporating label information and not manipulate the data being collected leads to a successful learning experience of the product.

References

¹ Imram, N. (1999) The role of visual cues in consumer perception and acceptance of a food product. Nutrition and Food Science, 5 (September/October), 224-228.

² Monaco, R. D., Cavella, S., Di Marzo, S. and Masi, P. (2004) The effect of expectations generated by brand name on the acceptability of dried semolina pasta. Food Quality and Preference, 15, 429-437.

³ Nasser, A., Dine, El. and Olabi, A. 2009. Effect of Reference Foods in Repeated Acceptability Tests: Testing Familiar and Novel Foods Using 2 Acceptability Scales. J of Food Science, 74, 2, p 97-106.

⁴ Jover, A. J.V., Montes, F. J. L., & Fuentes, M. d. M. F. (2004) Measuring perceptions of quality in food products: the case of red wine. Food Quality and Preference, 15(5), 453-469.

⁵ Beriain, M. J., Sanchez, M. and Carr, T. R. (2009) A comparison of consumer sensory acceptance, purchase intention, and willingness to pay for high quality United States and Spanish beef under different information scenarios. J Animal Science, 87, 3392-3402.

⁶ Moskowitz, H. R. (1985) New Directions for Product Testing and Sensory Analysis of Foods, Westport, Connecticut: Food & Nutrition Press, Inc pg 53.

⁷ Siret, F. and S. Issancho (2000) Traditional process: influence on sensory properties and on consumers’ expectation and liking Application to pate de campagne. Food Quality and Preference 11 p 217-228.

⁸ Bower, J. A., Saadat, M. A. and Whitten, C. (2003) Effect of liking, information and consumer characteristics on purchase intention and willingness to pay for a fat spread with a proven health benefit. Food Quality and Preference, 14, 65-74.

⁹ Berger, I. E. and Mitchell, A. A. (1989) The effect of advertising on attitude accessibility, attitude confidence, and the attitude-behavior relationship. J Consumer Research, 16 (3), 269-279.

¹⁰ Levis, P.A. and Chambers, E. IV. (1996) Influence of health concepts and product acceptance: a study with plain potato chips. J. Food Prod. Marketing 3(4): 45-63.

¹¹ Deliza, R. and MacFie H. J. H. (1996) The generation of sensory expectation by external cues and its effect on sensory perception and hedonic ratings: A review. J Sensory Studies, 11, 103-128.

Bibliography: Some Examples of Relevant Studies

¹² Allison, R. I. and Uhl, K. P. (1964) Influence of beer brand identification on taste perception. J. Marketing Research, 1 (3), 36-39.

¹³ Bengston, R. and Brenner, H. (1964) Product test results using three different methodologies. J. Marketing Research, 1 (4), 49-52.

¹⁴ Bilkey, Warren J. and Erik Nes, (1982) Country of origin effects on product evaluations. J. International Business Studies 13:1 p 89-99.

¹⁵ Cardello, A. V. (1994) Consumer Expectations and Their Role in Food Acceptance. Measurement of Food Preferences, New York: Blackie Academic & Professional, 253-297.

¹⁶ Dichter, Ernest (1962) The world customer. Harvard Business Review, 40 p 113-122.

¹⁷ Feltzenstein, C., & Dinnie, K. (2005) The effects of country of origin on UK consumers’ perceptions of imported wines. J. Food Products Marketing, 11(4), 119-127.

¹⁸ Gimenez, A., Ares, G. and Gambaro, A. (2008) Consumer attitude towards shelf-life labeling: does it influence acceptance? J. Sensory Studies, 23, P871-883.

¹⁹ Guinard, J. X., Uotani, B. and Schlich P. (2001) Internal and external mapping of preferences for commercial lager beers: comparison of hedonic ratings by consumer blind versus with knowledge of brand and price. Food Quality and Preference, 12, 243-255.

²⁰ Issanchou, S. (1996) Consumer expectations and perceptions of meat and meat product quality. Meat Science, 43, S5-S19.

²¹ Jover, A. J. Verdu, Montes, F. J. L. and Maria del Mar Fuentes (2004) Measuring perceptions of quality in food products: The case of red wine. Food Quality and Preference, 15, 453-469.

²² Moskowitz, H. R., Benzaquen, I. and Ritacco, G. (1981) What do consumers really think about your product? Food Engineering, 1 (Nov), 80-82.

²³ Peterson, Robert A. and Alain J. P. Joliber (1995) A meta-analysis of country of origin effects. J. International Business Studies 26:4 p 883-900.

²⁴ Quagrainie, K. K., Unterschultz, J. and Veeman, M. (1998) Effects of product origin and selected demographics on consumer choice of red meats. Canadian J. Agricultural Economics, 46, 201-219.

²⁵ Roosen, J., Marette, S., Blanchemanche, S. and Verger, P. (2007). The effect of product health information on liking and choice. Food Quality and Preference 18, 759–770

²⁶ Sosa, M. and Sidel, J.L. (2006) Sensory expectations of children from different household incomes for branded confectionery product. J. Sensory Studies, 21(2), 155-164.

²⁷ Steenkamp, (1990) Conceptual model of the quality perception process. J. Business Research, 21, p 309-333.

²⁸ Tuorila, H., Andersson, A., Martikainen, A. and Salovaara, H. (1998). Effect of product formula, information and consumer characteristics on the acceptance of a new snack food. Food Quality and Preference 9, p313–320

²⁹ Verlegh, Peeter W. J. and Jan-Benedict E. M. Steenkamp, (1999) A review and meta-analysis of country of origin research. J. of Economic Psychology 20, p 521-546.

³⁰ Vázquez, M.B., Curia, A. and Hough, G. 2009. Sensory descriptive analysis, sensory acceptability and expectation studies on biscuits with reduced added salt and increased fiber. J. Sensory Studies, 24, p 498-511.

Astringency is a sensory attribute that is described as a drying-out, roughening, and puckery sensation felt in the mouth. Foods that are often astringent include red wine, green and black teas, soy-based foods, and certain fruits, especially when they’re not yet ripe. In these foods, astringency is caused by the polyphenolic compounds they contain. Polyphenols are the most common cause of astringency in foods, though acids, metal salts such as alum , and alcohols are known to also cause astringency¹.

Sensory assessment of astringency

Astringency tends to be a difficult sensory attribute to assess because it takes over 15 seconds to fully develop, and it builds in intensity and becomes increasingly difficult to clear from the mouth over repeated exposures²³. A few approaches can be employed to overcome these issues: one suggested approach is the use of statistics to unearth “true” ratings without the carryover artifact, but this does nothing to reduce the cumulative effects of the sensation that can lead to taster fatigue⁴. A second option is to delay subsequent tasting of astringent samples until the oral environment has returned to a baseline state, although the strength of the sample and the number of sample repetitions will impact the interstimulus period needed for this to occur. A third option is to use a palate cleanser between samples. Several cleansers have been identified for their ability to alleviate astringency including various viscous polysaccharides and gums (e.g., pectin or carboxymethylcelluslose), oils, and also crackers⁵⁶⁷⁸; however, there is recent evidence suggesting that palate cleansers capable of reducing astringency may be masking the sensation in subsequent tastings⁹.

The cause of astringency

The majority of studies on astringency support the notion that astringency is primarily a tactile sensation rather than a taste⁶. The mechanism of astringency is not fully understood, although it is known that polyphenols bind and precipitate a class of salivary proteins called the proline-rich proteins (PRPs)¹⁰. One theory is that the precipitation of PRPs from saliva reduces its ability to lubricate, and this loss of lubricity is perceived as an increase in oral friction¹¹. A second theory proposes that the sensation is caused by a direct effect of astringents on the oral epithelium and that PRPs play a protective role and prevent astringency by binding the astringent compounds before they can interact with the oral mucosa¹². Both theories predict that people with high salivary flow rates and protein/PRP concentrations will report lower ratings of astringency. Several studies support this prediction^12131415.

References

¹ Green, B.G. 1993. Oral astringency: a tactile component of flavor. Acta Psychol 84(1):119-25.

² Guinard, J.X., Pangborn, R.M., Lewis, M.J. 1986. The time-course of astringency in wine upon repeated ingestion. American Journal of Enology & Viticulture 37(3):184-9.

³ Lyman, B.J., Green, B.G. 1990. Oral astringency: effects of repeated exposure and interactions with sweeteners. Chem Senses 15(2):151-64.

⁴ Arnold, G. 1983. A tasting procedure for assessing bitterness and astringency. In: Anonymous Sensory Quality in Foods and Beverages: Definition, Measurement and Control. American ed ed. Chichester, West Sussex; Deerfield Beach, Fla.: E. Horwood Ltd; Verlag Chemie International. P109—114.

⁵ Brannan, G.D., Setser, C.S., Kemp, K.E. 2001. Effectiveness of rinses in alleviating bitterness and astringency residuals in model solutions. J Sens Stud 16(3):261-75.

⁶ Breslin, P.A.S., Gilmore, M.M., Beauchamp, G.K., Green, B.G. 1993. Psychophysical evidence that oral astringency is a tactile sensation. Chem Senses 18(4):405-17.

⁷ Colonna, A.E., Adams, D.O., Noble, A.C. 2004. Comparison of procedures for reducing astringency carry-over effects in evaluation of red wines. Australian Journal of Grape & Wine Research 10(1):26-31.

⁸ Ross, C.F., Hinken, C.,Weller, K. 2007. Efficacy of palate cleansers for reduction of astringency carryover during repeated ingestions of red wine. J Sens Stud 22(3):293-312.

⁹ Lee, C.A., Vickers, Z. M. 2010. Discrimination among astringent samples is affected by choice of palate cleanser. Food Quality & Preference 21(1):93-99.

¹⁰ Baxter, N.J., Lilley, T.H., Haslam, E., Williamson, M.P. 1997. Multiple interactions between polyphenols and a salivary proline-rich protein repeat result in complexation and precipitation. Biochemistry (NY) 36(18):5566-77.

¹¹ Clifford, M.N. 1997. Astringency. Proceedings of the Phytochemical Society of Europe 41(Phytochemistry of Fruit and Vegetables):87-107.

¹² Horne, J., Hayes, J., Lawless, H.T. 2002. Turbidity as a measure of salivary protein reactions with astringent substances. Chem Senses 27(7):653-9.

¹³ Fischer, U., Boulton, R.B., Noble, A.C. 1994. Physiological factors contributing to the variability of sensory assessments: relationship between salivary flow rate and temporal perception of gustatory stimuli. Food Quality & Preference 5(1, 2):55-64.

¹⁴ Imm, B., Lawless, H.T. 1996. Relationships between salivary responses and astringency, bitterness and sourness responses to aluminum ammonium sulfate. Chem Senses 21(5):618.

¹⁵ Kallithraka, S., Bakker, J., Clifford, M.N., Vallis, L. 2001. Correlations between saliva protein composition and some T-I parameters of astringency. Food Quality & Preference 12(2):145-52.

Focus groups are qualitative research tools used to explore/understand consumers’ perceptions, opinions, beliefs, and attitudes (POBAs)¹ regarding a specific topic. A fundamental element of a focus group is the moderator. The skills and qualities (SAQs) of a moderator are keys to success for an effective group. Below are 10 key SAQs every moderator should practice²³⁴

1. Build Rapport- smile, make eye contact, and allow introductions; create a warm, supportive, and comfortable environment.

2. Be an Active listener- focus on what is being said; use respondent comments as you paraphrase/summarize; nod your head; lean forward as you listen.

3. Remain Neutral yet Involved- maintain objectivity both verbally and non-verbally; remember 80:20 rule- the participants talk 80% of the time and the moderator 20%.

4. Be Flexible- adapt to the flow of the discussion; remain open to changes in the moderator’s guide; adjust to client’s requests during the group; change your physical behavior-sit, stand, or walk around the room.

5. Use the “5-second Pause” and “Probe” techniques- ask clear questions and pause for consumers’ responses; probe for more information/ clarity of comments- avoid asking why.

6. Acknowledge and Respect- recognize each participant throughout the focus group session; respect various points of view, and emphasize respect among the group.

7. Practice good Organization/Management Skills- practice the guide, prepare for the unexpected; keep the discussion moving, focused, and within the established timeframe.

8. Have Knowledge of the topic- basic information on the subject helps in probing areas for more in-depth discussion; demonstrate a degree of naïveté.

9. Be Enthusiastic and Attentive- have a high energy level; pay attention to participants- recognize group dynamics.

10. Have a Sense of Humor- laughter keeps the group relaxed, encourages sharing of information, and helps the moderator maintain a human connection.

References

¹ Puchta, C. and Potter, J. (2004). Focus group practice. California: Sage Publications.

² Krueger, R.A. and Casey, M. (2000). Focus groups, 3rd Edition. California: Sage Publications.

³ Henderson, N.R. Fundamentals of moderating. Maryland: RIVA Training Institute.

⁴ Edmunds, H. (1999). The focus group research handbook. Illinois: NTC Business Books.

Food neophobia is a naturally occurring reaction in humans that protect individuals from the risk of being poisoned by consuming potentially harmful foods. It accounts for a person’s reluctance to consume either new or unusual foods, based on one’s culture and current diet (Rozin, 1997; Stallberg-white&Pliner;, 1999). Individuals may perceive and expect how an acceptable food should look and smell. As a consequence, an unfamiliar food that does not fall into one’s acceptable category will be rejected (Dovey et al., 2008). However, food neophobia may affects food choice and limits overall dietary variety especially in children (Pliner&Melo;, 1996; Falciglia et al., 2000; Skinner et al., 2002).

Factor effecting food neophobia

Food neophobia occurs in all type of consumers. The level of food neophobic response varies among individuals. The level of Food neophobia for each individual is affected by cultural, gender, age, education, social, economics, and urbanization (Tourila et al., 2001; Flight et al., 2003; Olabi et al., 2009).

Type of Food neophobia

Three types of consumers can be classified according to behavior of novel food rejection. These groups are: neophilic, neutral, and neophobic consumers. Neophilic consumers tend to accept unfamiliar foods. In contrast, neophobic consumers tend to reject unfamiliar foods. One way of determining which group a person is classified in uses the Food Neophobia Scale (FNS) developed by Pliner and Hobden (1992). That questionnaire measures one’s agreement/disagreement on 10 statements about novel foods or eating situations on a 7-point bipolar scale (1=strongly disagree to 7= strongly agree).

Type of Novel Food

Tuorila (2001) classified novel foods into five categories. The types of novel food are: (1) functional foods or medicinal food, the foods that claimed to promote health and immunity; (2) genetically modified foods, foods that are produced using gene technology; (3) nutritionally modified foods, foods that have better nutritional benefits than conventional foods; (4) organic foods, the foods are produced or farmed in traditional conditions, and (5) ethnic foods that are specifically familiar to one culture but unfamiliar to others.

Increasing Willingness to try novel food and Food neophobia reduction

An individual’s expectations toward food products have found to play a critical role in consumers’ motivation to try novel foods (Tuorila et al., 1994; Tuorila et al, 1998; Deliza&MacFie;, 1996; Jaeger&MacFie;, 2001; Hurling&Shepherd;, 2003). Consumers’ willingness to try novel food can be increased by providing positive experiences such as giving descriptive sensory (visual, odor, and taste exposures) and nutritional information. Information seems to be helpful to increase willingness to try novel foods and reduce food neophobia (Pelchat & Pliner, 1995; McFarlane & Pliner, 1997; de Graaf et al., 2005). Neophobia also can impact scores given to new foods in sensory acceptance tests (Henriques et al., 2008; King et al., 2008). Often “new” products receive lower scores than more familiar products because of the impact of neophobia. Ideas such as providing information on the product, serving new foods in the context of how they might be used, and testing the new product monadically (in contrast to testing within a set of other products) may help overcome the “penalty” often associated with neophobia (Tourila et al., 1995; Wansink et al., 2005, Deliz&MacFie;), but many of those idea remain undertested.

References

De Graaf, C., Cardello, A.V., Kramer, F.M., Lesher, L.L. Meisekman, H.L., & Scutz, H.G. (2005). A comparison between liking ratings obtained under laboratory and field conditions: The role of choice. Appetite, 44, 15-22.
Deliza, R., & MacFie, H.J.H. (1996). The generation of sensory expectation by external cues and its effect on sensory perception and hedonic ratings: A review. Journal of Sensory Studies, 11, 103-128.
Dovey, T.M., Staple, P.A., Gibson, E.L., & Halford. J.C.G. (2008). Food neophobia and ‘picky/fussy’ eating in children: a review. Appetite, 50, 181-193.
Falciglia, G.A., Couch, S.C., Gribble, L.S., Pabst, S.M., & Frank, R. (2000). Food neophobia in childhood affects dietary variety. Journal of the American Dietetic Association, 100, 1474-1478.
Flight, I., Leppard, P., Cox, D.N., (2003). Food neophobia and associations with cultural diversity and socio-economic status amongst rural and urban Australian adolescents. Appetite, 41, 51-59.
Henriques, A.S., King, S.C., & Meiselman, H.L. (2008). Consumer segmentation based on food neophobia and its application to product development. Food Quality and Preference, 20, 83-91.
Hurling, R., & Shepherd, R. (2003) Eating with your eyes: effect of appearance on expectations of liking. Appetite, 41, 167-174.
Jaeger, S. & MacFie, H.J.H. (2001). The effect of advertising format and means-end information on consumer expectations for apples. Food Quality and Preference, 12, 189-205.
King, S.C., Meiselman, H.L., Henriques, A. (2008). The effect of choice and psychographics on the acceptability of novel flavors. Food Quality and Preference, 19, 692-696.
McFarlane, T., & Pliner, P. (1997). Increasing willingness to taste novel foods: Effects of nutrition and taste information. Appetite, 28, 227-238.
Olabi, A., Najm, N.O., Baghdadi, O.K., Morton, J.M. (2009). Food neophobia levels of Lebanese and American college students. Food Quality and Preference, 20, 353-362.
Pelchat, M., & Pliner, P. (1995). “Try it: you’ll like it; effects of information on willingness to try novel foods. Appetite, 24, 153-531.
Pelchat, M. L. & Pliner, P. (1997). “Try It: It’s Good and It’s Good for You”: Effects of Taste and Nutrition Information on Willingness to Try Novel Foods. Appetite. 28: 89-102.
Pliner, P. & Hobden, K. (1992). Development of a scale to measure the trait of food neophobia in humans. Appetite, 19, 105-120.
Rozin, P. 1997. The Use of Characteristic Flavoring in Human Culinary Practice. In C. M. Apt (Ed.) Flavor: Its Chemical, Behavioral and Commercial Aspects. Boulder, CO: Westview Press.
Skinner, J.D., Carruth, B.R., Wendy, B., & Ziegler, P.J. (2002). Children’s food preference’s food preferences. Journal of American Dietetic Association, 102, 1638-1647.
Stallberg-white, C., & Pliner, P. (1999). The effect of flavor principles on willingness to taste novel foods. Appetite, 33(2), 209-221 Tuorila, H., Lahteenmaki, L., Pohjalainen, L., & Lotti, L. (2001). Food neophobia among the Finns and related responses to familiar and unfamiliar foods. Food Quality and Preference, 12, 29-37.
Tuorila, H., Meiselman, H.L., Bell, R., Cardello, A.V. & Johnson, W. (1994). Role of sensory and cognitive information in the enhancement of certainty and liking for novel and familiar foods. Appetite, 23, 231-246.
Tuorila, H., Meiselman, H., Cardello, A., & Lesher, L. 1998. Effect of expectations and the definition of product category on the acceptance of unfamiliar food. Food Quality and Preference. 9(6): 421-430.
Urala, N., & Lahteenmaki, L. (2006). Hedonic ratings and perceived healthiness in experimental functional food choices. Appetite, 47, 302-314.
Wansink, B., Ittersum, K., Painter, J. E., (2005). How descriptive food names bias sensory perceptions in restaurants. Food Quality and Preference, 16, 393-400.

Degree of difference testing, commonly abbreviated DOD, is a discrimination method used to determine if an overall difference exists between test and control products when the product shows inherent variability due to preparation, production time, multiple components, etc. With such variability, traditional 3-AFC and 2-AFC methods¹ cannot effectively separate true treatment variability from normal product variability, and therefore can give false results. Examples of heterogeneous products include prepared meals such as soups or entrees, baked goods such as cookies or rolls, and multi-component snack mixes.

An approach utilizing degree of difference (DOD) testing was proposed by Aust, Gacula, Beard, and Washam (1985)² wherein scaled difference ratings were used to contrast the difference between the control and the test samples to a baseline difference between control lots. Panelists scaled overall difference for three pairs of samples – Control lot 1 (C1) vs. C1, C1 vs. Control lot 2 (C2), and C1 vs. Test (T). The difference between the control and test was then compared to within-lot and between-lot variability of the control to establish if the control-test difference was significant.

Recognizing that this standard DOD approach may not detect the situation where Test is outside of normal control lot variability, Pecore, Stoer, Hooge, Holschuh, Hulting and Case³ modified this methodology by doubling comparisons between the control and test lot products by eliminating the C1-C1 pair and adding a C2-T pair. This modified method thus incorporates a measure of control lot variability, and has been abbreviated DOD-CV.

A further extension of this method is to include test lot variability as well, which has recently been published as the DOD-CTV method (Young, Pecore, Stoer, Hulting, Holschuh and Case⁴).

References

¹ Lawless, H. T., & Heymann, H. (1998). Sensory evaluation of food. New York: Chapman & Hall.

² Aust, L. B., Gacula, M. C., Jr., Beard, S. A., & Washam, R. W. II, (1985). Degree of difference test method in sensory evaluation of heterogeneous product types. Journal of Food Science, 50, 511–513.

³ Pecore, S., Stoer, N., Hooge, S., Holschuh, N., Hulting, F., & Case, F. (2006). Degree of difference testing: A new approach incorporating control lot variability. Food Quality and Preference, 17(7–8), 552–555.

⁴ Young, T., Pecore, S., Stoer, N., Hulting, F., Holschuh, N., & Case, F. (2008) Incorporating test and control product variability in degree of difference tests. Food Quality and Preference, 19, 734-736.

In this basic tutorial, we will walk through all of the steps necessary to create a new wiki article from scratch. If you just want to edit an existing article, much of this tutorial will not be of interest. Instead, you may want to read the article editing help topic.

If you are writing your first article for the wiki, you may know that it is completely new (if not, try doing a “search” or check the “title list”). In such a case, type the name of the proposed article into the “create or find page” field and click on the “Go” button. In this example, we will create a new wiki article called “Article Example”. Given below is an annotated screen shot of doing this first step.

Screen Shot 1 – Use “Create or Find Page”

When you click on the “Go” button, the web page will refresh and look as follows:

Screen Shot 2 – Verification that no such article exists

Now, you would click on the “Edit” menu button tab. This will bring up a new web page which will display a text area field for entering your article. This is shown below:

Screen Shot 3 – Blank Article Form

There is some special wiki syntax that tells the wiki how to format (display) the article and also how to categorize it. To ensure that your article is filed under an appropriate category, you have enter the name of the category within a double set of brackets and proceed the category name with the word “Category” followed by a colon. There should not be any spaces between the colon and the category name. If you include a space, this will cause a new category to be created that has a leading space in it. This is illustrated next:

Screen Shot 4 – Entering the article’s Category

Also shown in the screen shot is entering a brief description of the type of change that is being made. In this case, we simply write that this is the first version.

Next, you will typically enter in the body of your article. If you wish, you may copy and paste it from another source (such as Word), but keep in mind that the wiki has its own way to format text.

Screen Shot 5 – Entering the rest of the article

As you are writing your article, be sure to make use of the Preview button. The preview button is your best friend. It will show you how the article will ultimately look on the wiki, but without committing the article text into the wiki database. But, this also means that you haven’t really entered anything into the wiki until you click on the Submit button. In the next screen shot you will see what our example article looks like after using the preview button.

Screen Shot 6 – Use Preview to see article formatting

That’s the basics. At this point, you would finish by clicking on the “Submit” button, and the web page will show how your article looks in its final form. If you then spot an error or want to make additional formatting changes, you can still click on the “Edit” menu tab button, and make further changes. But don’t forget to enter another brief note as to what kind of change (primarily) you are making.

Generalized Procrustes Analysis

Generalized Procrustes Analysis (GPA) is a multivariate technique used to analyze data from different panelists¹. It was initially developed for use in analyzing data generated from Free-Choice Profiling (FCP). GPA equalizes the terms/attributes and scale usage used in the panelist-specific vocabularies from FCP. Instead of using mean values like PCA, GPA uses individual scores to account for any variance. Since all panelists evaluate the same samples, the samples remain constant and do not vary³.

Analysis of variance (ANOVA) may be run on the data to identify significant attributes. Subsequent GPA can demonstrate the product/attribute and the panelist scores in the sensory space. Combined with ANOVA, recognizing singular panelists is straightforward. The graphical representation of GPA is easy to interpret as vectors illustrate the distance of panelist responses from the origin. This also indicates relationships between panelists and products, including product differences and panelist agreement (indicating outliers, etc). PCA by attribute may be conducted on the data as well. However, it is not as visually pleasing or easy to interpret with regard to panelist agreement [2].

References

¹ Gower, JC. 1975. Generalized procrustes analysis. Psychometrika, 40, 33-51.

² Meullenet, JF, Xiong, R, and Findlay, C. 2007. Multivariate and Probabilistic Analyses of Sensory Science Problems. Iowa: Blackwell Publishing Professional.

³ Xiong, R, Meullenet, J-F, and Dessirier, JM. 2008. Permutation tests for Generalized Procrustes Analysis. Food Quality and Preference, 19, 146-155.