by Giulia Pecoraro
Aim of the experiments: detect the impact of beer in-store layout and shelf designs on consumer attention and purchase decision.
This research presents a scenario that we are going to define as “scenario 1” (or “virtual scenario”).
Protocol scenario 1
- Galvanic skin response (GSR),
- Facial coding,
- Pc monitor.
- For the eye tracking: the areas of interest (AOI) within the heat map, the time spent in every AOI, fixation sequences.
- For the GSR: the peaks measured by the galvanic skin response.
- For the facial coding: interpretation of facial emotion.
20 subjects have to be enrolled on a voluntary base. They have to be divided in two groups with the same number of participants (Group A and Group B). Each participant have to fill in and sign an informed consent form prior to the participation in the study.
Creation of the planograms shown in the video clips:
Two video clips were created in order to perform a randomization of the beers on the shelf. The positions used on the shelf follow the logic for how real products are placed on shelves in stores. The two planograms (resolution: 4.8 megapixel) are made up of a sample size of 60 bottles representative of 20 brands. By randomizing the products, it is possible to observe if the amount of attention received by the product is related to its position on the shelf and the participant’s purchase decision. In order to perform the test, two planograms with different product positioning were showed for 20 seconds each to two different groups of participants: Planogram 1- Group A; Planogram 2- Group B.
Eye tracker, galvanic skin response and facial coding registrations of 20 subjects watching a short video clip of 53 seconds compose the whole dataset. The subjects are divided in two groups with the same number of participants (10 each) and watch two different video clips. The subjects are not aware of the aim of the recording, and they only know to pay attention to the material showed on the screen during the entire 53 seconds. Each video clip is made up of two different parts: a calibration part consisting of a video clip showing a ball bouncing around the screen (20 seconds), and the experiment part consisting of an image of a beer planogram (20 seconds). After the biomarker registrations, each subject is asked to fill out a questionnaire on Google docs. The questionnaire consists of demographic, attitudinal, consumer, behavioural and package design questions. The hypothesis is that the position of the beer on the shelf has an influence on the consumer’s attention and purchase decision.
- Choose a quiet room to carry on the experiment. Try to keep noise from the surrounding environment at a minimum.
- Lightening condition: avoid direct sunlight (if the room has any windows, close the blinds) as sunlight contains infrared light that can affect the quality of the eye tracking measurements. Do not use overhead light. Ideally use ambient light. Remember not to overlit the room.
- Temperature: the ideal laboratory temperature is between 23-26°C.
- Make sure to place all system components on a table that does not wobble or shift.
- The eye tracker should be mounted below the computer monitor.
- The webcam should be mounted on the top of the computer monitor.
Equipment Mounting and Recording Condition Control:
- Invite the participant to sit on a comfortable chair in front of the monitor
- To collect the eye movement, switch the eye tracker on.
- Check that the eye tracker is being correctly acquired by verifying on the eye tracker software.
- To collect the facial expressions, switch the webcam on.
- Check that the facial coding is being correctly acquired by verifying on the facial coding software.
- Clean the skin of the participant’s non-dominant hand with a chlorhexidine antiseptic solution to disinfect it and to remove the most superficial lipid layer that has accumulated on the skin.
- To collect the GSR, place two electrodes on the second and third fingers of the participant non-dominant hand. Place the electrodes on the palmar side of the second phalanx.
- Check that the GSR is being correctly acquired by verifying the presence of the proper waveform on the software interface.
- Instruct the participant, equipped with the recording instruments, to watch a short video clip during which the signal recordings take place. Furthermore, ask the participant to limit any movement and to stay as relaxed as possible for the duration of the video clip.
- Start the video clip 1 for the participants of group A, and video clip 2 for the participants of group B. The first scene of both the video clips is created to calibrate the biomarker instruments. The second scene is the effective experiment whose results must be analysed.
- At the end of the video clip, remove the GSR electrodes from the respondent.
- Administer the questionnaire to the respondent by opening the Google docs link.
 Tobii® Technology, Eye tracking as a tool in package and shelf testing, p.8:
“To be able to compare whether or not the position has an impact one would typically show the pictures to two different groups of similar people; one group would see the product in position A and one group would see the product in position B”.
Tobii® Technology, Tobii Eye Tracking, An introduction to eye tracking and Tobii Eye Trackers, pp.7-8:
“Before an eye tracking recording is started, the user is taken through a calibration procedure. During this procedure, the eye tracker measures characteristics of the user’s eyes and uses them together with an internal, physiological 3D eye model to calculate the gaze data. This model includes information about shapes, light refraction and reflection properties of the different parts of the eyes (e.g. cornea, placement of the fovea, etc.). During the calibration, the user is asked to look at specific points on the screen, also known as calibration dots. During this period several images of the eyes are collected and analyzed”.
 iMotion, Eye tracking-The complete pocket guide,p.23.
 Butler JM, Johnson JE, Boone WR. The heat is on: room temperature affects laboratory equipment–an observational study. J Assist Reprod Genet. 2013;30(10):1389-1393. doi:10.1007/s10815-013-0064-4
 Tobii T60XL Eye Tracker, Widescreen eye tracking for efficient testing of large media, p. 2.
A wide screen is recommended for eye tracking shelf testing, the 24-inch screen is the best option given that 27″ is the maximum screen size allowed.
 Tobii T60XL Eye Tracker, Widescreen eye tracking for efficient testing of large media, p. 5:
“All precision measurements are done at 60 Hz sampling rate and a distance of 65 cm (26”)”.
 Boucsein, W. et al. Publication recommendations for electrodermal measurements. Psychophysiology. 49, 1017-1034 (2012).