Data from ‘words only’ and ‘numbers only’ 9-point hedonic scales are not interchangeable for serial monadic as well as rank-rating protocols: Aspects of memory and culture

American, Chinese, Thai and Mexican consumers were required to assess products on two types of 9-point hedonic scale. One type, the ‘words only’ scale, consisted of the traditional verbal labels to which the numbers 1–9 are later attributed for numerical analysis. The second type, the ‘numbers only’ scale was a numerical scale ranging 1–9, along with the appropriate information indicating the directions of liking vs disliking. For the same stimuli, consumers used the ‘words only’ and ‘numbers only’ scales differently, indicating that the data from the two scales were not directly comparable. This was found for both the rank-rating and serial monadic protocols. With the latter protocol, consumers sometimes gave responses on the 9-point hedonic scale that were inconsistent with their rankings of liking. There was a strong tendency for the mean range of responses for the ‘words only’ scale to be less than for the ‘numbers only’ scale.     

The 9-point hedonic scale: Are words and numbers compatible?

The original 9-point scale, developed by the U.S. army for menu planning for their canteens, consisted of a series of nine verbal categories representing degrees of liking from ‘dislike extremely’ to ‘like extremely’. For subsequent quantitative and statistical analysis, the verbal categories are generally converted to numerical values: ‘like extremely’ as ‘9’, ‘dislike extremely’ as ‘1’. Yet, sometimes what is termed a 9-point hedonic scale is an unstructured numerical scale, labeled at the ends with ‘dislike extremely’ and ‘like extremely’. The former scale requires consumers to categorize foods according to how much they are liked or not; the latter requires the consumers to differentiate numerically between the foods in terms of the relative degree of liking for each. Foods that were placed in the same verbal category for the former scale might be given different numerical scores on the second scale. To illustrate this, consumers rated five chocolates, in a series of experiments, on these two types of 9-point scale (verbal categories only vs numbers only) and the proportion responding differently to the two scales ranged from 100% to 79%. This indicated that numerical data obtained from both types of 9-point scale were not interchangeable. It also suggested that consumers were using different cognitive strategies for verbal categories and numbers. To check that the difference was not caused by the fact that the verbal categories were bipolar and the numbers unipolar, the experiment was repeated using a bipolar number scale (–4 through 0 to +4). The same results were obtained. For comparison, a 9-point hedonic scale including both verbal categories and numbers together, was also used. The results for this scale showed a greater similarity to the version of the 9-point scale consisting only of verbal categories than the unstructured numerical version. Stimulus equalizing bias was used as a tool to make a preliminary investigation into the cognitive strategies involved for the two versions of the scale. The hypothesized relative strategy was confirmed for the unstructured numerical scale but the hypothesized absolute strategy was not confirmed for the scale using only verbal categories; the strategy appeared to have relative elements. Regardless of the precise nature of the cognitive strategies used for two versions of the scale, they do not give the same results and data obtained from each version should be compared with caution.     

Comparison of the Hedonic General Labeled Magnitude Scale with the Hedonic 9‐Point Scale

The hedonic 9‐point scale was designed to compare palatability among different food items; however, it has also been used occasionally to compare individuals and groups. Such comparisons can be invalid because scale labels (for example, “like extremely”) can denote systematically different hedonic intensities across some groups. Addressing this problem, the hedonic general Labeled Magnitude Scale (gLMS) frames affective experience in terms of the strongest imaginable liking/disliking of any kind, which can yield valid group comparisons of food palatability provided extreme hedonic experiences are unrelated to food. For each scale, 200 panelists rated affect for remembered food products (including favorite and least favorite foods) and sampled foods; they also sampled taste stimuli (quinine, sucrose, NaCl, citric acid) and rated their intensity. Finally, subjects identified experiences representing the endpoints of the hedonic gLMS. Both scales were similar in their ability to detect within‐subject hedonic differences across a range of food experiences, but group comparisons favored the hedonic gLMS. With the 9‐point scale, extreme labels were strongly associated with extremes in food affect. In contrast, gLMS data showed that scale extremes referenced nonfood experiences. Perceived taste intensity significantly influenced differences in food liking/disliking (for example, those experiencing the most intense tastes, called supertasters, showed more extreme liking and disliking for their favorite and least favorite foods). Scales like the hedonic gLMS are suitable for across‐group comparisons of food palatability.     

Effects of an evoked refreshing consumption context on hedonic responses to apple juice measured using best–worst scaling and the 9-pt hedonic category scale

Awareness of the need to consider a product’s consumption context when measuring consumer hedonic response of a product is increasing among consumer sensory researchers. This study investigated the effects of evoking a consumption context using a written scenario on hedonic response measured using best–worst scaling and the 9-pt hedonic category scale. Hedonic responses for four apple juices with relatively large sensory differences were compared when measured in the evoked context ‘when having something refreshing to drink’ using best–worst hedonic scaling (n = 65) and the 9-pt hedonic scale (n = 48). Best–worst scaling discriminated between the four apple juices when a refreshing context was evoked (p < 0.01), while the juices were equally liked using the 9-point scale (p = 0.41) when the same context was evoked. Consumers perceived best–worst scaling to be more difficult than the 9-pt scale, however there was no difference between the two methods for consumers perceived accuracy of their liking information. The present study highlights that the effect of an evoked context on hedonic response may not be universal for hedonic methods. Further research is needed to understand the effect of evoking context on the liking of products, and to determine whether this measure reflects product liking in an actual consumption context.     

How Argentine consumers understand the Spanish translation of the 9-point hedonic scale

The objective of this work was to study how ambiguous the meaning of the Spanish translation of the 9-point hedonic scale was for Argentine consumers. Three versions of the 9-point hedonic scale were tested: a literal translation of the original English version, a liberal translation of this same scale and the liberal translation of a scale phrased for children (e.g. where ‘like extremely’ was replaced by ‘super good’). Children, adolescents and adults from two cities of Argentina, making up a total of 288 subjects, performed the tests. These consisted in ranking the phrases from each one of the three scales from ‘like least’ to ‘like most’. In most cases the scale phrased for children performed best. Using this scale approximately 30% of the subjects ranked the translated phrases differently in relation to the English version, that is inverted the order of two or more phrases. The results from the present work show that the use of the 9-point hedonic scale translated to languages different to English should be done with caution.     

Kinetics of sensory quality changes in soymilk during thermal processing,by parametric and non‐parametric data analyses

Soymilk was subjected to various heat treatments at 90, 120 and 140 °C for various lengths of time. The colour and flavour of the soymilk samples were evaluated by a sensory panel consisting of eight semi‐trained assessors on (1) a 9‐unit hedonic scale, with analysis based on the assumption that the units are equidistant, and (2) a 15‐point hedonic ‘Smiley’ pictorial scale, the results being analysed non‐parametrically. The proportion (%) of ratings higher than or equal to/higher than the overall median of the samples was used as a rigorous estimate of product quality. These values were used to determine the colour and flavour changes in heated soymilk and their temperature dependence. The Z‐values derived from the parametric and non‐parametric analyses were in close agreement, ranging from 31 to 33 °C and from 30 to 32 °C for colour and flavour respectively. © 2000 Society of Chemical Industry     

The concurrent use of JAR and CATA questions in hedonic scaling is unlikely to cause hedonic bias,but may increase product discrimination

The concurrent use of CATA questions (check-all-that-apply) with hedonic scaling in product research with consumers has gained acceptance in recent years. However, CATA questions do not enable product developers to identify consumers’ preferred intensity of a sensory attribute directly, and for this reason just-about-right (JAR) questions are sometimes used together with questions that quantify attribute presence and/or intensity. Using JAR questions, consumers have to describe each of the samples in terms of each specific attribute, typically: 1 = ‘Not enough…’, 3 = ‘Just about right’, and 5 = ‘Much too…’. Past research has suggested that co-elicitation of hedonic and JAR responses bias the hedonic data. This undesired effect could extend to the case where JAR questions are used concurrently with hedonic and CATA questions. In seven studies (N = 762) across seven product categories no such evidence was found. Additionally, there was some evidence pointing to an increase in product discrimination based on hedonic and CATA responses. Preliminary data indicated that the inclusion of JAR questions in product tests also eliciting hedonic and CATA responses did not negatively affect consumers’ perception of the task, which, on average, was still regarded as easy and not tedious. Future research is required to validate the findings across more varied experimental settings.     

Comparison of best–worst and hedonic scaling for the measurement of consumer wine preferences

Background and Aims:  Best–worst scaling (BWS) is compared to standard hedonic scaling for measuring consumer wine preferences. BWS is a relatively new method for producing ratio-level scales and has gained recent attention for application in sensory research, but has not been applied to wine.
Methods and Results:  Regular wine consumers (112) evaluated eight designed wines with both scaling methods in an intra-subject design over two test periods. The methods did not result in comparable product liking results. The eight wines could almost be differentiated on an aggregated level with hedonic ratings ( P  = 0.076); there was no significant difference with BWS. Latent class analysis was used to identify two clusters, which differed on the preferences for the designed sensory components. The BWS design had to be split into several blocks, so no complete individual measures were available, which prevented analysing heterogeneity for this method.
Conclusions:  BWS needs more wines to be assessed per person in order to discriminate between red wines and to allow modelling of consumer preference heterogeneity. Respondents would have to accomplish complete individual BWS designs, which requires repeated exposure to the same set of wines over several tasting sessions.
Significance of the Study:  This study demonstrates that BWS is not as suitable for sensory consumer preference measurement of red wine as hedonic rating. While BWS has shown a higher discriminative ability for different products and in non-sensory research, the factors of alcohol, tannin and memory fatigue make it less practical for red wine sensory measurement compared to hedonic rating.     

Comparison of discriminability of common food acceptance scales for the elderly

This study was aimed to compare four commonly used methods for evaluating consumer acceptance (the 5-point and the 9-point hedonic scales) and preference (the ranking scale and the best-worst scaling) in terms of their ability in discriminating samples and perceived ease of use by the elderly. Elderly (n = 100) and young adult (n = 100) consumers participated in this study. Each consumer evaluated five commercial orange juice samples in duplicate for hedonic rating and preference rank separately and then evaluated ten sets of three samples for the best-worst scale, following the balanced incomplete block design. Nonparametric tests were employed as normality of data was violated. A significant sample effect was observed in all four methods (P < .001). Discriminating power of the best-worst scaling was more pronounced in the elderly than in the young adults; however, the best-worst scaling was easy to use for the young adults than for the elderly.     

RATA questions are not likely to bias hedonic scores

Concurrent elicitation of hedonic and sensory information from consumers helps to identify the sensory attributes that drive consumer preferences. However, there is a risk that asking consumers about specific sensory characteristics can bias their hedonic responses. This research extends previous work by investigating if concurrent use of rate-all-that-apply (RATA) questions, a variant of CATA questions is associated with bias of the hedonic scores. RATA questions extend CATA questions by requiring consumers to also rate the intensity of the terms that are applicable for describing samples (‘high’, ‘medium’ and ‘low’). In eight consumer studies (n = 560) across five product categories there was no evidence of concurrent use of RATA questions influencing hedonic scores. When RATA questions were used concurrently with a hedonic question there was a strong tendency for greater hedonic discrimination between samples (5 of 8 studies). This suggested that the discriminative capacity of the hedonic question was increased by inclusion of the RATA question, a result that could be attributable to the RATA question increasing consumers’ engagement and attention to the task. Further research is required to confirm this result and tentative explanation.     

Characteristics of formed Atlantic salmon jerky

Abstract: Smoked salmon (Salmo salar L.) processing may generate large amounts of small pieces of trimmed flesh that has little economic value. Opportunities exist to develop new added‐value foods from this by‐product. Brining was compared with dry salting for the production of formed salmon jerky‐style strips that were then smoked. The formulations also contained brown sugar and potato starch. Salted samples had higher salt concentrations and required less force to break using a TA‐XT2 Texture Analyzer. Brined samples contained more fat and were darker, redder and more yellow than the salted samples. Processing concentrated omega‐3 fatty acids compared with raw salmon, and the brined jerky had the highest omega‐3 fatty acid content. A panel of 57 consumers liked the appearance and aroma of both samples equally (approximately 6.7 for appearance and 6.3 for aroma on the 9‐point hedonic scale. Higher acceptability scores for taste, texture, and overall quality were given to the brined product (6.7 to 6.9 against 6.2 to 6.3). Practical Application: Salmon trim from smoking facilities can be utilized to produce a jerky that is a good source of omega‐3 fatty acids, simultaneously adding value and reducing the waste stream.     

Direct and indirect hedonic scaling methods: A comparison of the labeled affective magnitude (LAM) scale and best–worst scaling

Affective or hedonic measurement is a cornerstone of sensory science, because it provides critical information about individuals’ likes and dislikes for different products. Therefore, it is not surprising that debate about hedonic scaling is ongoing and that new methodology for hedonic scaling emerges regularly. The present research adds to this body of knowledge by comparing best–worst (BW) scaling, a choice-based methodology, with a direct scaling method, the labeled affective magnitude (LAM) scale. We begin with a literature review of direct and indirect scaling methods and then present two empirical studies that compare best–worst and LAM scaling. The key finding is that neither scaling method is superior to the other. However, what tentatively emerges is that choice of scaling method needs to be made in the context of the nature and complexity of the study to be conducted, the nature of the respondents, and the nature of the test samples themselves. With numerous criteria influencing the choice of hedonic scaling methodology, we advocate that researchers be explicit about the criteria that underlie their empirical work.     

What do we learn from comparing hedonic scores and willingness-to-pay data?

Consumer preferences for different variants of a given food product can be directly obtained with hedonic measurements or revealed with willingness-to-pay measurements. The aim of this paper is to present a comparison of the data collected using these two types of measurements on four data sets collected in our laboratory for different food products (bread, cooked ham, cheese and orange juice). This comparison was conducted at two levels (global and individual) and was based on two criteria: discrimination between variants and consistency in variant ranking. For the four data sets, hedonic measurements and willingness-to-pay measurements were collected for each participant in a ‘full information’ condition, i.e. in a condition where participants tasted each variant associated with extrinsic information. To reveal consumer willingness-to-pay, the BDM mechanism was used (Becker, DeGroot, & Marschak, 1964), which consists in real sales at a random price. Aggregate results were similar for the two measurements. In addition, in two out of four studies, willingness-to-pay measurements led to slightly higher discrimination between variants than hedonic measurements. At the individual level, more inconsistencies were found. This result is in line with previous studies. Nevertheless, participants were more consistent concerning the most-liked variant than concerning the least-liked variant. Our results also showed that hedonic score distributions did not reveal any cut-off point below which consumers chose the no-purchase option; this cut-off point largely depended on individuals and products.     

Temporal aspects of hedonic and intensity responses

The present study investigated temporal aspects of hedonic responses. The focus was on the hedonic response in itself and on the time-course of the hedonic response as compared to the intensity response. Analogously to time–intensity (TI) scaling, we used temporal scaling for intensity and pleasantness aspects of taste. Twenty four subjects were instructed to focus on and continually rate either the intensity or the pleasantness of three different concentrations of an orange lemonade stimulus in a within-participants design. As was expected, the latency and the time to maximum of the intensity response were shorter than the latency and time to maximum of the hedonic response. Unforeseen, the intensity response lasted longer than the pleasantness response. These results suggest that initially the processing of the intensity and pleasantness aspects is in serial and later on may be in parallel. Our study confirms that, as was suggested by Taylor and Pangborn [Journal of Sensory Studies 4 (1990) 241–247], time–hedonic scaling can be performed.     

Questionnaire Design: Carry‐Over Effects of Overall Acceptance Question Placement and Pre‐evaluation Instructions on Overall Acceptance Scores in Central Location Tests

Question placement and usage of pre‐evaluation instructions (PEI) in questionnaires for food sensory analysis may bias consumers’ scores via carry‐over effects. Data from consumer sensory panels previously conducted at a central location, spanning 11 years and covering a broad range of food product categories, were compiled. Overall acceptance (OA) question placement was studied with categories designated as first (the first evaluation question following demographic questions), after nongustation questions (immediately following questions that do not require panelists to taste the product), and later (following all other hedonic and just‐about‐right [JAR] questions, but occasionally before ranking, open‐ended comments, and/or intent to purchase questions). Each panel was categorized as having or not having PEI in the questionnaire; PEI are instructions that appear immediately before the first evaluation question and show panelists all attributes they will evaluate before receiving test samples. Postpanel surveys were administered regarding the self‐reported effect of PEI on panelists’ evaluation experience. OA scores were analyzed and compared (1) between OA question placement categories and (2) between panels with and without PEI. For most product categories, OA scores tended to be lower when asked later in the questionnaire, suggesting evidence of a carry‐over effect. Usage of PEI increased OA scores by 0.10 of a 9‐point hedonic scale point, which is not practically significant. Postpanel survey data showed that presence of PEI typically improved the panelists’ experience. Using PEI does not appear to introduce a meaningful carry‐over effect.     

West African sorghum beer fermented with Lactobacillus delbrueckii and Saccharomyces cerevisiae: shelf‐life and consumer acceptance

The fermentation profiles, shelf‐life and consumer acceptance of traditional West African sour sorghum beer (pito) fermented with pure commercial starter cultures of lactic acid bacteria (L. delbrueckii) and yeast (Saccharomyces cerevisiae) were evaluated. The beers from this ‘pure culture’ approach were compared with the spontaneous fermentation of pito wort. Lactic acid formation, pH change and extract utilisation were monitored during fermentation. Lactic acid content was used as a measure of sourness to establish the spoilage level of over‐sourness. Further, regression models relating sourness to the time the drink was kept were used to predict the shelf‐life. Consumer acceptance of the product was evaluated using a novel nine‐point hedonic scale. The pure culture and traditionally fermented beers followed similar lactic acid and fermentation profiles but strain‐specific differences were observed. Similar levels of pH, lactic acid level and extract utilisation were achieved. An improvement in shelf‐life of two days was found over traditionally fermented pito. There was no statistical difference between the two pito products for overall liking and taste. However, there was a preference for the aroma of the pure culture pito. It is suggested that the use of pure cultures will facilitate the scale‐up of pito production. © 2019 The Institute of Brewing & Distilling     

Hedonic scaling: A review of methods and theory

In recent years, interest in measuring hedonic responses has grown tremendously in both basic psychophysics and applied food and consumer research, resulting in the development of several new hedonic scaling methods. With these developments have come questions about theoretical and practical differences among the methods. The goal of this review is to compare and contrast these different approaches for the purpose of aiding researchers in selecting the most appropriate scaling method for their specific measurement needs. The review begins by addressing fundamental issues in scaling methodology, including the role of context effects, then moves on to describing and discussing the development of various types of hedonic scales, their specific properties, and their potential advantages and disadvantages.     

Are consumer profiling techniques equivalent for some product categories? The case of orange‐flavoured powdered drinks

Taking into account consumers’ perception in new product development has been regarded as a key strategy to developing more successful food products. In this context, consumer profiling techniques have increased their popularity in the last decade. The aim of the present work was to compare four consumer profiling techniques (sorting, projective mapping, intensity scales and check‐all‐that‐apply questions) in orange‐flavoured powdered juice drinks. A consumer study was carried out with 200 regular consumers of the category, which were divided into four groups. Each group used a different methodology to evaluate seven commercial powdered drinks. After completing the task consumers were asked to rate its difficulty on a nine‐point hedonic scale. Results showed that the four evaluated methodologies were able to identify differences in consumers’ perception of the sensory characteristics of the drinks, providing similar information. However, the application of CATA questions and intensity scales was regarded as easier for consumers. Advantages and disadvantages of the evaluated methodologies are discussed.     

A new approach to measuring Overall Liking with the Many-Facet Rasch Model

The 9-point hedonic scale is the most common hedonic rating scale used to provide an assessment of overall liking. Studies have shown that consumer judgements of overall liking could be influenced by their ratings of the liking of flavour, texture, aroma or appearance. However, this is not directly taken into account when using the holistic variable of overall liking. A new approach is proposed for measuring overall liking that is firstly based on initially considering what sensory characteristics (attributes or modalities) defines the latent sensory construct of OVERALL LIKING. The aim of this study was to develop a single measure of Overall Liking that incorporates the relative importance of liking ratings from different sensory characteristics by applying a Many-Facet Rasch model to produce interval-scaled estimates of Overall Liking. A homogeneity test found significant differences (p < 0.01) between the Rasch means estimates of the cured 10 hams that were evaluated by a consumer panel (n = 90), with the two different definitions of the Rasch measure of Overall Liking. No significant differences were found when comparing Rasch measures with raw scores using an intrablock BIB ANOVA and Durbin test. The degree of Relevance, shown on a Many-Facet Wright map, indicated the extent which a variable contributed to the measure of Overall Liking. Of the 10 sensory attributes used for the Individual Attribute Measure, Hardness and Juiciness contributed the most, while Sweetness and Typical Flavour contributed the least. However, the modalities used in rating the Likings of Overall Flavour, Texture, Aroma and Appearance contributed almost to the same extent to Overall Liking in the Total Attribute Measure. The Wright Map also showed that the categories on the 9-point hedonic scale were unequally spaced and the distance between them became increasingly larger the further away from the central category of ‘Neither like nor dislike’.