Grocery shopping is a task based activity.
Often times we will walk into an aisle and play out a heuristic script which leads us to select the same product that we always have.
Searching for that product is a process of elimination guided by familiar signals such as the shape and colour of packaging.
In these circumstances, for a product attempting to build market share, disrupting this process and gaining a shopper’s attention is no mean feat.
The mere fact that our attention is focussed on a task and a preconceived target item means that we do not attend to other products on the shelf even when they are in our line of sight.
This is clearly evident from the world famous selective attention test performed by Simons & Chabris (1999) below:
But if this is the case, just what can a manufacturer do to increase the chances of successfully gaining a shopper’s attention?
In their publication Inattentional Blindness, Arien Mack of the New School for Social Research and Irvin Rock of the University of California describe a series of experiments which may at least help.
In these experiments Mack & Rock’s subjects were first asked to fix their gaze on a point at the centre of a computer screen (fixation point) and were then momentarily (for 200 milliseconds) shown a cross and asked which line making up the cross was the longest, thereby creating a task based focus for attention not unlike the target of a shopper’s purchase intent on a shelf.
In some cases an additional object termed the Critical Stimulus was also introduced alongside the cross and within the subject’s field of vision. Following exposure, subjects were asked if they recalled seeing anything other than the cross on the screen and in a significant number of cases it was found that the additional object had gone completely un-noticed in the same way that the gorilla goes un-noticed in Simons & Chabris’s video.
However Mack and Rock take things a step further in an attempt to identify which properties will make it more or less likely to capture attention.
The results are interesting
In one set of experiments, the cross is positioned in the centre of the screen (the subjects fixation point) whilst the critical stimulus is positioned away from it but still within the Parafovea (2.3 degrees from the fixation point) and so well within the field of vision (diagram A). This was compared to an alternate situation where the Critical Stimulus was positioned on the fixation point and the cross in the Parafovea (diagram B).
The results at first seem counterintuitive. If the Critical Stimulus is positioned on the point of fixation (diagram B), then surely more people will notice it? But the opposite seems quite clearly to be the case. The fact that subjects are forced to move their point of fixation towards the cross in order to complete the task of estimating which axis of the cross is longest actually makes them far less likely to report the presence of the Critical Stimulus.
This has potentially significant implications for the position of products on a shelf since if brands hoping for uplifts in sales are paying a premium for an optimum eye level position in the planogram in the attempt to attract more attention, then this may be money unwisely invested as shopper’s searching for their recognisable brand may be less rather than more likely to see the other product as a result.
This is not to say that a brand which is the target of a shopper’s search is not better placed in a premium location as it will be found more quickly, but for those products that a shopper is not looking for, the eye level is buy level mantra may not necessarily apply.
Shape and Colour
To establish the degree to which shapes and colours are perceived and therefore attract attention Mack and Rock went on to conduct a series of experiments in which the shape and colour of the Critical Stimulus were varied.
Alongside being asked if they had noticed anything other than the cross on the screen, those subjects who said they had done so were asked to recall either the shape or colour of the Critical Stimulus dependent upon what was being examined within the given experiment.
Additional experiments under conditions of divided attention (when the subject was asked to both evaluate the longest axis of the cross and assess the shape / colour of the Critical Stimulus) and full attention (when the subject was asked to report the shape / colour of the Critical Stimulus alone) were conducted for comparative purposes.
The results showed that the ability of subjects to report the shape of a Critical Stimulus even when they recalled seeing it (it had caught their attention) in the inattentive experiment was very low and no better than chance, but when prompted to pay attention to the shape in the divided and full attention scenarios this rose significantly.
The result suggests that the shape of an object does not determine its ability to be perceived in a situation of inattention and therefore its ability to attract attention is low.
In contrast subject’s abilities to report the colour of a Critical Stimulus were considerably better under inattentive conditions and much better than chance.
Consequently in situations of inattention the perception of colour and its ability to attract attention are shown to be much stronger.
The implication for packaging design here is that colour is a significantly more important feature to concentrate upon than is shape when attempting to attract a shopper’s attention.
One example of how this works this may be the black bleach bottles which appeared on supermarket shelves several years ago. At this time I recall conducting an in-store eye tracking project in which these vividly contrasting products commanded a significant amount of visual fixation.
Black bleach bottles contrasting with the typical whites and blues
This however is not to say that shape is not important once attention has been gained, but purely on the basis of attracting attention, colour would seem to be a significantly more powerful mechanic.
The colours used for different types of products in different aisles also provide us with more general cues which help us navigate our way around the supermarket. Rather like the picture below where the combination of black blobs in total provide us with an image of a Dalmatian dog so the combinations of colours in a supermarket aisle signal to us which aisle we are in. This is perhaps at its most pronounced for ketchup where a huge bank of red bottles often referred to in the business as “The Red Wall” tells us exactly what is down that aisle.
But attracting our attention is only one part of the process. Once a product has our attention it needs to close the sale.
In closing the sale, packaging must also communicate to us something of relevance that allows us to determine if the product is what we want. So whilst for instance a red milk bottle may stand out extremely well and attract our attention it is unlikely to close the sale since in the context of milk, red packaging does not give us the right signals about the product it contains.
We don’t on the whole tend to spend very long in selecting a product once we are standing in front of a supermarket shelf, a matter of seconds is not uncommon and certainly more than a minute is unusual.
Given this limited window of opportunity we therefore need to find the right medium through which to communicate the benefits of our product.
In his book The User Illusion, Danish Physicist Tor Norretranders describes the amount of information that as humans we are able to perceive through our sight, touch, hearing, smell, taste etc… in any given second. This he calls the bandwidth of our senses and he expresses each bandwidth in computer terms, likening sight to the bandwidth of a computer network whilst at the other end of the spectrum, taste is compared to a pocket calculator.
Bandwidth of our senses – Tor Norretranders
Crucially, we are not consciously aware of much of the information that is perceived by our senses (only the small white dot in the bottom right corner of the diagram above can be consciously perceived in any given second). But that is not to say that we do not process, respond and react to all the information that is processed by our subconscious.
Because reading is by nature a conscious activity our ability to process and comprehend text is extremely limited in comparison to visual information, and so the use of colours, imagery and carefully chosen words which act as metaphors for more detailed and compelling concepts are the order of the day on the supermarket shelf.
There is an entire science called Semiotics devoted to the study of the cultural meaning of signs, symbols and colours; and packaging designers must tap into this to communicate by the most effective and visual means possible the reasons why we should buy a product.
Let’s take another example, this time from the cheese aisle. Cheese is a product where connotations of quality are strongly linked to a sense of artisan craftsmanship and heritage. So the packaging design for the cheese shown below uses a number of devices to convey this impression of the product to the shopper. The use of a burgundy red colour has connotations with something regal and perhaps special and this is further enhanced by the use of gold. The name itself also acts as a metaphor for heritage and perhaps expertise which has gone into its manufacture.
Our considerations when buying products in a supermarket will inevitably vary according to the nature of the product we are buying. As such the design elements used in packaging for different types of products vary to reflect this.
So what can we learn from all this when we are attempting to design packaging which will give our products the best chance of success in a highly competitive environment such as a supermarket aisle?
- If you’re the underdog think twice about paying a premium for a central position on the fixture – it may actually do you a disservice and being close but not bang on centre may be good enough.
- Whilst packaging shape is potentially important further down the line to communicate benefits it may not be that important in attracting attention in the first place so make colour a first priority.
- Consider the dominant packaging colours in the category and choose something that will stand out from the crowd.
- Ensure your packing colour is relevant though – no-one wants to buy red milk.
- Consider the semiotics of you packing, your choice of palette and imagery are more quickly interpreted than text in the short time that you have to communicate and can speak a thousand words.