The Role of Customers= Arousal For Retail Store - Results From an Experimental Pilot Study Using Electrodermal Activity As Indicator

Andrea Groeppel-Klein, European University Viadrina
Dorothea Baun, European University Viadrina
ABSTRACT - As reported in different empirical studies based on insights of environmental psychology, visual merchandising and interior design of store environments must evoke an optimum level of customers’ arousal. However, valid verbal measurement of arousal is difficult to determine: Traditional interviews are mostly done after the shopping trip through a store or a particular part of the store so that customers have to remember their emotions. That means using self-reporting methods only allow to measure activation and/or emotions with a time-lag. Moreover, the validity of verbal scales that are intended to measure a psychophysiological response must be called into question. Conversely, electrodermal activity (EDA) is considered to be a valid and also very sensitive indicator that clearly responds to the smallest variation in arousal. Latest technical development offer larger storage capacity, thus allowing telemetric measurement of electrodermal activity which in turn makes field experiments in retail stores possible.
[ to cite ]:
Andrea Groeppel-Klein and Dorothea Baun (2001) ,"The Role of Customers= Arousal For Retail Store - Results From an Experimental Pilot Study Using Electrodermal Activity As Indicator", in NA - Advances in Consumer Research Volume 28, eds. Mary C. Gilly and Joan Meyers-Levy, Valdosta, GA : Association for Consumer Research, Pages: 412-419.

Advances in Consumer Research Volume 28, 2001     Pages 412-419

THE ROLE OF CUSTOMERS= AROUSAL FOR RETAIL STORE - RESULTS FROM AN EXPERIMENTAL PILOT STUDY USING ELECTRODERMAL ACTIVITY AS INDICATOR

Andrea Groeppel-Klein, European University Viadrina

Dorothea Baun, European University Viadrina

ABSTRACT -

As reported in different empirical studies based on insights of environmental psychology, visual merchandising and interior design of store environments must evoke an optimum level of customers’ arousal. However, valid verbal measurement of arousal is difficult to determine: Traditional interviews are mostly done after the shopping trip through a store or a particular part of the store so that customers have to remember their emotions. That means using self-reporting methods only allow to measure activation and/or emotions with a time-lag. Moreover, the validity of verbal scales that are intended to measure a psychophysiological response must be called into question. Conversely, electrodermal activity (EDA) is considered to be a valid and also very sensitive indicator that clearly responds to the smallest variation in arousal. Latest technical development offer larger storage capacity, thus allowing telemetric measurement of electrodermal activity which in turn makes field experiments in retail stores possible.

The present paper delivers insights on arousal theory and presents empirical results from a pilot study using EDA to measure arousal. An experiment comparing two retail stores with different environmental settings was conducted.

SHOPPING ENVIRONMENT AND AROUSAL

Fierce competition and saturated markets in retail business make it more and more important for retailers to gain competitive advantage over rivals in order to attract and keep customers. The store atmosphere is playing a major role in this context.

An activating store atmosphere is necessary to evoke positive feelings and approach behavior. However, high orientation pleasantness is necessary, otherwise the store atmospher is perceived as cluttered and chaotic by the consumers and negative emotions and avoidance are the result.

Environmental psychology is a special field of psychology modeling the influence of diverse environments (e.g. buildings, rooms, landscapes, or other environments of human beings) on emotion and behavior (Mehrabian 1978, 1976). We can gain knowledge from both cognitive and affective approaches of environmental psychology on how store environments affect consumers’ arousal and emotions during their shopping trips. However, as we shall see later, empirical findings so far have not brought out clear results on how arousal and shopping behavior are related. This might at least partly be due to the measurement method.

COGNITIVE APPROACHES OF ENVIRONMENTAL PSYCHOLOGY AND CONSUMERS’ AROUSAL

The central question of cognitive approaches to environmental psychology concern the ability of individuals to perceive, realize and remember environments. Findings of brain research, perception theory and gestalt theory can help explain the memory representation of spatial information, the so called "mental maps" (Ittelson 1977, Russell and Ward 1982, Golledge 1987).

Several empirical studies of store environments (e.g. Sommer and Aitkens 1982, Grossbart and Rammohan 1981, Bost 1987) give evidence of a significant correlation between the existence of store maps (knowledge about the location of specific products, service centers, escalators, cashier’s zone, etc.) and sentiments regarding shopping convenience. Grossbart and Rammohan draw the conclusion that retailers should study the imparting of verbal and non-verbal information in order to improve the internal maps of consumers. Such "landmarks" can be provided by "merchandising themes" (products that are usually used together are presented side by side in the store and decorated as taken from life), visually striking elements, and clearly separated aisles and product display zones.

Consequently, in order to best achieve orientation pleasantness in retail stores, a most favorable level in stimulation is recommended: a clear and simple structure which is cognitively "relaxing" on the one hand, but highly activating key objects that help to form mental store maps on the other hand (Groeppel 1991, Groeppel-Klein 1998b, Flicker and Speer 1990, Wener 1985).

EMOTIONAL APPROACHES OF ENVIRONMENTAL PSYCHOLOGY AND AROUSAL

Using the Stimulus-Organism-Response (S-O-R) model as theoretic basis, Mehrabian and Russell (1974) developed an emotion dominated model of environmental psychology. Various stimuli (e.g. colors, music, shapes) engender primary emotional responses, which provoke reactions to that environment.

Mehrabian and Russell (1974) characterize an environment by the "information rate", defined as the novelty (the unexpected, surprising, unfamiliar in an environment) and the complexity (the number of elements, motins or changes in the setting) of an environment. The more varied, novel, surprising and animating the environment, the higher is the information rate. Environmental stimuli generate primary emotional reactions of three fundamental dimensions - pleasure, arousal, and dominance. According to Mehrabian and Russell (1974) arousal states the active, excited, stimulated, fidget feeling. "Pleasure" means an individual is joyful and in a good mood. "Dominance" states that you "feel unrestricted or free to act in a variety of ways" (Mehrabian and Russell 1974, p. 19). The response variable can turn out into "approach behavior" (an individual reacts positively to an environment) and "avoidance behavior" (characterized by an aversion to the environment).

The environmental psychology model of Mehrabian and Russell (see figure 1) has been used as theoretical framework for several empirical investigations on point-of-sale (PoS) environments.

Donovan and Rossiter (1982) were the first researchers to apply this model to retail stores. They investigated emotional states produced from three different store environments. For the reaction variable they gathered data on test subjects’ stated behavioral intention (approach B avoidance) by asking for the time people had stayed in the store, the probability that they would spend more money than planned in that particular store, and the likelihood that they would return. Donovan and Rossiter’s findings revealed that both, arousal and pleasure perceived in pleasant store environments determine the following:

+ shopping enjoyment

+ time spent in the store for browsing and exploring

+ willingness to talk to sales personnel

+ tendency to spend more money than originally planned

+ probability to return to the store

FIGURE 1

STUDIES AT THE POS BASED ON THE MEHRABIAN AND RUSSELL MODEL

For neutral or unpleasant stores regression coefficients between arousal and the response variables did not turn out to be significant.

In a second study Donovan, Rossiter, Marcoolyn, and Nesdale (1994) extended the study of Donovan and Rossiter from 1982. Basically, the same methodology was applied. [In the second study the variable "dominance" was not examined because it had not shown significant difference in the first study.] However, only respondents who were not familiar with the store environment were interviewed. Instead of the wide range of stores considered in the first study, only discount department stores were employed in the second study. Pre-measures of reaction variables (estimated spending and time to be spent in the store) were compared to post measures. Arousal and pleasure was measured "during" the shopping experience. "During" here means that the test subjects were interviewed after they had spent five minutes shopping in the store.

The results of this second study show again that the variable "pleasure" predicts the response variables "intended shopping behavior" and also the actual shopping behavior. Contrary to the first study, arusal did not show significant positive effect on the response variables in pleasant store environments. The prediction for unpleasant stores (higher arousal will reduce spending) was found to be significant contrary to results of the first study.

Donovan, Rossiter, Marcoolyn, and Nesdale (1994) wonder whether the differences between the results of the first and the second study might be due to the minor changes in the experimental design. Yet, the verbal scale might also be a reason for distortion. The authors report that for some customers it had been difficult to relate items like "aroused-unaroused", "jittery-dull", and "frenzied-sluggish" to their experienced feelings. Another problem might be that in the 1994 study as well as in the previous study, the item "relaxed" was applied to measure both, the pleasure and the arousal variable.

Flicker and Speer (1990) employed a renovated store as the experimental store and another, not renovated store as the control store for their study. They used the same scale for arousal and pleasure as Donovan and Rossiter did for their study in 1982. No significant relation was found between arousal and the response variables (avoidance B attraction; intended B actual behavior), neither for the control store nor for the experimental store.

Van Kenhove and Desrumaux (1997) also tested the Mehrabian-Russell model on behalf of pleasure-arousal and impacts on approach and avoidance behavior in seven large retail stores (clothing, furniture, and garden centers) in Belgium. Subjects not familiar with the stores were interviewed five minutes after entering the store. Van Kenhove and Desrumaux applied Donovan and Rossiter’s original scales on pleasure, arousal, approach and avoidance behavior, translated into Dutch. These researchers found a clear importance of arousal for all three behavioral variables. However, exploratory and maximum likelihood confirmatory factor analysis revealed that a large number of the original items from the pleasure/arousal-scale are not good indicators to measure pleasure and arousal. Van Kenhove and Desrumaux come to the conclusion "that careful inspection of the items selected to test the pleasure/arousal approach-avoidance relationship is needed" (p. 364). Nevertheless, these researchers summarize that this relationship could be of high interest for retailers.

Investigations of Groeppel-Klein (Groeppel-Klein, 1998a, 1997) in Germany revealed, that a store atmosphere that evokes pleasure, a relaxed mood state, and dominance results in a positive value-for-money assessment, and a positive attitude towards the interior design. Also, the duration of staying in the store is extended and consumers rate their intention to come back with a higher probability. Thus, the interior design on the one hand needs to bring about arousal, but on the other hand it shall not exceed an optimum level resulting in a frantic mood.

SUMMARY AND RESEARCH QUESTIONS

Summarizing the results of these studies one can conclude that the variable "arousal" plays a major role. Thus, the "right mix of stimulus factors" is crucial for retailers. Yet, the question arises whether the items of the arousal scale are good indicators. In all studies mentioned, verbal scales were used to indicate arousal. Ar the differences between the results of the studies at least partly due to the applied scales?

The most important question is how to measure the arousal evoked from a specific environmental setting with a higher validity than verbal scales, to determine:

+ whether arousal influences emotional states (that means emotions play a mediating role for the response variables) and

+ whether there is a difference between consumer behavior in higher and in lower arousing store environments.

A look from a psychophysiological perspective on the construct "arousal" and the association with emotional constructs such as "pleasure" leads to the conclusion that verbal scales might not be an appropriate way to measure arousal.

FIGURE 2

THREE DIMENSIONAL MODEL ON AROUSAL

A PSYCHOPHYSIOLOGICAL PERSPECTIVE: INSIGHTS FROM AROUSAL THEORY

Unidimensional concepts of arousal theory describe the Reticular Activating System ([RAS], which comprises the sensoric inflow, the Reticular Formation [RF], as well as cortical, hypothalamic, and thalamic areas) as the fundamental component for the formation of arousal (Boucsein 1992, 1997). The RF is a complex network of fibers and cell bodies in the core of the brain stem. It is involved in the filtering process of sensory information from the central nervous system (e.g. from visual, haptic, acoustic stimulation). According to these theories, all sensory and motor nerve fibers can enhance general arousal of the RF via collaterals. The RF in turn can indistinctly activate large parts of the central nervous system, generating general activity and reactivity. Thus, an increase of inner or outer stimuli might lead to a higher activation and attention, whereas habituation to these stimuli lead to de-activation and tiredness (Boucsein 1997).

The unidimensional approach would suggest correlation between diverse physical outcomes of arousal such as heart rate, blood pressure, EEG (Electroencephalogram), or EDA (electrodermal activity). Since empirical findings were not consistent with this unidimensional approach, recent efforts yielded towards a more complex arousal theory (Eysenck 1982, Le Doux 1996). Boucsein (1997, 1991), for example, presented a three-dimensional theoretical framework based on neurophysiological insights on arousal and information processing (see figure 2). The model also considers the dependency between arousal and emotion / motivation as well as the effects on central and peripheral psychophysiological parameters. In this model, the first dimension is in accordance with the concept of the unidimensional approach. That means the RF forms the physiological basis of this dimension. EEG (Electroencephalogram) can serve as an indicator. Reults from the first dimension are perceived as general activation with a vigilant feeling and an alert state of mind. The second dimension, the "affect-arousal"-system, comprises primarily emotional components of arousal. Headed by the Amygdala, attention, orienting reflex and overall behavior is enhanced via hypothalamic reactions. The physiological outcome results in phasic cardiovascular (heart rate) and/or tonic electrodermal variations. When it comes to behavior and perception, processes of this second dimension lead to defense and negative emotions. Attention that turns into an orienting reflex may also directly impinge on the third system. This so-called "preparatory activation"-system is basically encompassing motivational aspects of arousal. Expectations are transformed into a ready state for reaction. This part of the system interacts especially with motor and pre-motor activation of behavior, and with positive emotion. Phasic electrodermal amplitude, for example, can serve as an indicator.

For marketing purpose, and especially when testing the impact of in-store stimuli on customers’ arousal and behavior tendency, the "preparatory activation"-system and in part the "affect-arousal"-system (here especially attention and orienting reflex) are of major relevance (Groeppel-Klein 2000, Boucsein 1997).

Arousal is definitely considered as being fundamental to behavior that is related to emotions (Bagozzi, Gopinath and Nyer 1999) and, as previously shown, arousal plays a major role for customers’ interaction with the store environment. Yet, despite diverse methods applied in order to measure arousal, the variable is extremely difficult to indicate in a valid manner. Among the applied methods are verbal scales like the PAD-scale (Donovan and Rossiter 1982), non-verbal scales (e.g. color- and pattern-scale, Meyer-Hentschel 1983), and self-reporting methods. The PAD-scale has been discussed above. The color- and the pattern-scale of Meyer-Hentschel has not yet been implemented often enough to support valid conclusions. Responses from self-reporting methods often suffer from distortion (Vitouch 1997). Another way to approach arousal B but in fact rather measuring emotion B is the observation of non-verbal communication, especially facial features e.g. via FAST [FAST=Facial Affect Scoring Technique] (Ekman, Friesen, and Tomkins 1971) or FACS [FACS=Facial Acting Coding System] (Ekman and Friesen 1978, Bekmeier 1989) or the use of picture scales that represent specific emotional states (Groeppel and Bloch, 1990).

In contrast to these methods, psychophysiological measures such as heart rate, EEG and EDA are the most valid indicators, since willingly influencing test results is almost impossible.

Electrodermal activity in general "is regarded as a sensitive and valid indicator for the lower arousal range, reflecting small, mostly cognitively conditioned variations in arousal." (Boucsein 1992, p. 263). Contrary to the heart rate, the EDR points to even the very smallest psychological change (Boucsein 1992). It is thus delivering the most sensitive indicator of arousal that might potentially be relevant to behavior. EDR can therefore deliver a valuable contribution to further research on the consumers’ arousal induced shopping behavior.

ELECTRODERMAL ACTIVITY AS PSYCHOPHYSIOLOGICAL INDICATOR FOR AROUSAL

The human skin basically consists of two layers, the dermis and the epidermis. The epidermis is located at the surface and consists of epithelial tissue. This layer is more callous, the closer to the surface. The comparatively thicker and deeper lying dermis consists of taut, fibrous connective tissue. Underneath the dermis lies the subcutis, which contains the secretory part of the sweat glands, fatty tissue, and vessels that supply the body surface (Boucsein 1992).

The epidermis is of great importance to EDA. Although it becomes dryer towards its outside layer as the regularly arranged cells become less tightly packed, there is a permanent insensible perspiration from the dermis via the epidermis even while no sweat gland activity occurs. This hydration depends on external and internal factors and leads to good electric conductivity of the skin, thus making it possible to measure it by means of two electrodes attached to the skin. The conductivity of the skin is then transmitted to the computer by means of an amplifier. The conductivity of the skin is primarily responsible for tonic EDA, while active membrane processes following upon a nerve impulse bring about phasic EDA which turns into electrodermal reactivity (Boucsein 1992). Following the three dimensional model of Boucsein (1997), phasic electrodermal reactivity (EDR) is the most crucial indicator for research concerning arousal at the point-of-sale.

Basically EDA can be measured via endosomatic or exosomatic recording. While endosomatic recording does not use any external voltage to measure potential differences on the skin, exosomatic recording uses either direct current (DC) or alternating current (AC). Exosomatic recording with direct current is most frequently used to measure either skin conductance (SC, measured in FS [FS=mikrosiemens. Siemens is the unit to measure conductance between two objects.]) or skin resistance (SR, measured in kW [kW=kiloohm. Ohm is the unit to measure resistance between two objects.]). Each of these methods measures both, skin conductance / resistance level (tonic arousal) as well as skin conductance / resistance reactivity (phasic arousal) from the EDA-signal (Boucsein 1992).

For practicability and safety reasons for test subjects, exosomatic recording must strongly be recommended for in-store investigations since endosomatic recording requires one of the electrodes being placed in an "inactive" site on the skin that has been pretreated (so called "skin-drilling"). For exosomatic measurement both electrodes are simply attached to the left palm of right-handed test persons or vice versa for left-handers. (For a detailed description of recording sites see Boucsein 1992).

EXPERIMENTAL DESIGN

The following empirical investigation was conducted in November 1999 and was intended to deliver a first experience in recording EDA at the point-of-sale. A questionnaire was applied in addition for control reasons. Testing the influence of different stimuli settings on arousal was of major interest.

The investigation was conducted in the fruit and vegetable department of two Austrian grocery stores. Both stores belong to the same retail chain and are located in a distance of a ten minutes walk from another. The management of that retail chain pursues different marketing strategies with both stores. For "Store 1" (opened at the beginning of 1999) insights from environmental pschology have been considered. Here, fruits and vegetables are presented in large-scale on broad and deep carriers and are arranged according to colors. Exotic fruits, fresh herbs and flowers are used as eye-catchers. Part of the products are presented on sort of an "island" in the middle. The whole store is spacious and high-ceilinged, and has bright electric light. In our investigation we treat this store as the experimental store. In "Store 2", our control store that was opened in 1974, the same assortment of fruits and vegetables are offered. Quality and prices are exactly equal. However, insights from environmental psychology have not been considered for the store decoration. The light appears less bright. Shelves are put along side the wall and display tables are arranged in a row in the middle of a long and narrow aisle. Contrary to "Store 1", an extraordinary product presentation (for example, by an arrangement according to colors) was not applied.

We hypothesize that the "Store 1" that is decorated according to the principles of environmental psychology would evoke higher arousal than the ordinary "Store 2". That is, customers of "Store 1" would be more highly aroused during shopping than customers of "Store 2".

In the experimental store 15 test persons were asked to do their ordinary shopping in the vegetable department while EDA was registered. [For registration we chose an exosomatic approach applying DC (0.4V) and measuring skin conductance. The technical equipment runs with a 12 bit A/D (analog to digital) converter. We used two Ag/AgCl electrodes filled with a 0.5% NaCl electrode creme. Electrodes were attached to the left palm of right-handers and vice versa. The apparel allows telemetric online registration and is thus suitable for studies at the point-of-sale.] In the control store we collected EDA data from 12 test persons. Test customers were asked to participate right after entering the store. The two electrodes were attached to the palm of those who agreed. Both, the EDA apparel and the telemetric device were either laid in the trolley or put in the test subject’s pocket. The data was transmitted via the telemetric device to the computer that was installed at the end of the fruit and vegetable department for online registration. From that part of the store, we also observed the participants. In both stores the fruit and vegetable section is the first part of the store the test subjects walked through. Before they went on to another part of the store, electrodes were detached and registration stopped. Each individual was then asked to answer a standardized questionnaire. The questionnaire was the same for both stores.

TABLE 1

TABLE 2

RESULTS FROM EDA MEASUREMENT

Concerning socio-demographic data, no significant differences were found between the two samples concerning age, education, number of persons living in the same household, income and sex.

Prior to statistical evaluation from EDA, parameters have to be extracted from recordings. In order to gain valid parameters, we first excluded all artifacts [Among the most frequently detected artifacts during our measurements were for example turning the trolley too rapidly by using the hand connected to the electrodes, "struggling" to tear off one of the plastic bags for fruits and vegetables, any kind of pressure upon electrodes, or change in intimacy of contact between electrode and skin. In some cases also speech activity occurred and was excluded as artifact. For a detailed description of physiologically produced artifacts see Boucsein (1992).] from the recorded curves. Also the first part of the curves were not rated up to the point where the test subjects were used to the electrodes and their curve showed a consistent level.

For phasic EDA, the amplitude is the most frequently used parameter in order to describe each single reaction (Boucsein 1992; Cacioppo, Marshall-Goodell, and Gormezano 1983). For the calculation of the amplitude, an amplitude criterion needs to be defined: that is, the minimum an amplitude has to show in order to be evaluated as a "true" reaction to a stimulus. The amplitude might otherwise be due to a recording artifact derived from the frequency noise of the direct current (Boucsein 1992). Although signal-to-voice ratio of the applied apparel would allow an amplitude criterion of 0.01FS, we decided to apply 0.05FS in accordance with recommendations in the literature (Venables and Christie 198).

Basically, there are two ways to evaluate overlapping amplitudes: (1) The amplitude of the second reaction is measured from its peak to the extrapolated recovery line of the preceding amplitude; (2) evaluating the second amplitude from its own baseline regardless of the recovery time of the preceding amplitude. The latter method is considered to be standard and sufficient (Boucsein 1992) and was thus preferred in order to gain the amplitudes for our statistical evaluation.

With this paper we want to focus the impact of stimuli in the store environment on arousal. Therefore, when measuring arousal at the point-of-sale, we have two problems to deal with: (1) The test person is not exposed to a single stimuli but to the overall appearance of the store; (2) He/she can look at and approach whatever attracts attention for as long as he/she wants to. That means there is no fixed time a certain stimuli is presented. The first problem is similar to lab-examinations of TV-commercials. We therefore referred to Steiger (1988), who suggests to sum up the amplitudes per person recorded over the total length of the commercial (receiving the total amplitude). When summing up the amplitudes of the test persons produced over their controlled shopping time, we in fact found significant difference in total amplitudes for the two stores by means of a Mann-Whitney U Test [Mann-Whitney U was chosen to replace Independent Samples T-Test for the small samples here are not fulfilling the Normal Distribution assumption.] (see Table 1). This means that the experimental store evokes a higher arousal than the control store.

If each skin conductance response demonstrates special attention of the individual towards an object of its environment, the frequency of responses becomes relevant. Thus, Steiger (1988) also suggests evaluating the frequency of skin conductance responses. Our data shows significantly higher frequency in the response rate of test persons in the experimental store compared to those in the control store. This indicates that the environment of the experimental store provides more information that has potential to attract enough attention to be cognitively processed.

Yet, the second problem mentioned above (different duration of exposure to stimuli) is not solved with these parameters. If a pleasing store atmosphere also leads to a longer duration of stay, there should be a significant difference between both stores concerning this variable. We compared the duration of shopping in the fruit and vegetable section, which is equivalent to the duration of recording and is given on a 1/100-second index base. The mean length of stay is 13,142.33 sec. in "Store 1" and 7,547.83 sec. in "Store 2". The assumption turned out to be true as the Mann-Whitney U Test showed.

Concerning the time problem, one can argue that there should also be a difference in total arousal in a given period of time (arousal per minute). Comparing test subjects’ total amplitude per minute between both stores, the results point into the right direction; however the difference is not significant.

Considering these outcomes, it is fair to assume that once a product is discovered, it evokes higher arousal in "Store 1" than in "Store 2". Compared to the control store, more objects are discovered in the experimental store and the customer stays longer in the fruit and vegetable department. In other words, the experimental store has a higher arousing overall store atmosphere.

TABLE 3

TABLE 4

TABLE 5

RESULTS FROM THE QUESTIONNAIRE

Basically, EDA measures arousal, but the perceived emotion (cognitively interpreted arousal) that is derived from arousal cannot be indicated from any EDA parameter. We therefore used verbal scales with items on the overall store perception and emotions. In order to measure whether the perceived emotions were more or less positive, we used a German version of Izard’s (1994) positive dimensions of the Differential Emotions Scale (DES). The dimensions are "interest", "surprise", and "joy". For the total sample, both, the total amplitude and the frequency show significant correlation, but only with the item "glad" of the dimension "joy". Another scale on the overall appearance of the store that has been used in several previous studies in order to measure the information rate (Groeppel 1991, 1992) shows significant correlation between the item "varied" and the total amplitude, as well as with the amplitude per minute. There is also correlation on the 90% level between the item "varied" and the frequency of electrodermal response (see table 2).

On a five point disagreement-agreement scale products appeared more "irresistible" to test subjects in the experimental store than in the control store. A product they had picked had more often "suddenly caught their eye". Also test subjects in "Store 1" were significantly more "astonished", "happy", and "amazed" when discovering a chosen product compared to those in "Store 2".

The results of the DES-items and of the items "irresistible" as well as "caught my eye" can lead to the conclusion that a higher arousing store environment can also lead to a higher rate of unplanned and impulse purchases. Results are also in line with the above stated outcome from the frequency index.

CONTROL VARIABLES

From the cognitive approach of environmental psychology we learn that the perceived orientation pleasantness is an important variable. A store with many activating stimuli designed to serve as "landmarks" for cognitive maps should not be perceived as cluttered or chaotic. Therefore, we also measured orientation pleasantness. In addition we controlled the perceived price image of the two stores in order to check whether a store with a pleasant atmosphere and decoration is perceived as more expensive. This would lead to a boomerang for the retailer.

Table 4 shows that concerning the orientation pleasantness and the price image there is no significant difference between the two stores.

In addition, we took a larger sample size in order to control response variables. This sample also included all test persons who had been shopping with the EDA apparatus. The results from a Oneway ANOVA show significant differences in the intention variables "I will return to the shop", "I will recommend the store to others" as well as in the estimated amount spent during the last shopping trip in that particular store (see table 5).

One can summarize that optimum arousal evoked at the point-of-sale can improve the overall perception of the store, lead to a better information processing, extend the duration of stay and thus eventually enhance purchases.

CONCLUSION

The results show that recording EDA at the point-of-sale is a practicable way to measure arousal in a valid manner. The findings confirm hypotheses from environmental psychology and our hypothesis which postulates that the experimental store represents the higher arousing store environment. EDA can thus be a future research method in order to work out visual merchandising themes that evoke an optimum of arousal. EDA recording can also be applied to explore arousal and orienting reflexes derived from different environmental stimuli settings and the arousal potential of elements designed to be visually striking. Verbal scales that indicate arousal can also be validated. Furthermore, EDA records arousal evoked at the point of sale simultaneously to the perception of stimuli during shopping.

However, EDA recording has also limitations, especially concerning the time that is needed in order to collect satisfying sample sizes. Not every consumer is willing to be "connected" to electrodes. Also, as long as a computerized artifact detection is not possible, artifact detection needs to be done manually by screening each single curve. Another restriction is the fact that EDA cannot reveal whether an arousing situation was perceived with positive or with negative emotions, whether a situation was rather pleasing or unpleasing. Verbal control of perceived emotions by a standardized questionnaire is therefore necessary.

Further discussion is needed with respect to suitable parameters calculated from the EDA curves when data is collected at the point of sale.

Larger research samples may reveal the actual role of arousal for shopping behavior. What is the optimum information rate of a store environment, which stimuli can actually serve as eye catchers and which others are more suitable for relaxation in order to prevent a frantic mood? Despite the limitations, EDA seems to be a promising method in order to do further research on these and other open questions related to store environments.

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