By Mathieu Turpault, Director of Design at Bresslergroup

As technology evolves, designers are focused more on multisensory design. We're enthusiastic about its potential—but as with anything novel and compelling, there's a tendency for the pendulum to swing too far.

Too many early attempts at designing multisensory products tend to maximize for all or most senses without any consideration of context or of how the different senses relate to each other when people are processing information. (We get it—we had the same tendency of maximizing for all the senses when we first started.) While this is fine as an experiment, it's not appropriate as a product design methodology.

As we've dipped more into multisensory design, we've surveyed the breadth of relevant research being done (and that has already been done) in psychology and human factors. We've compiled a summary of it in our post, Psych for Product Designers: Research To Inform Multisensory Design.

This research has demonstrated that the most effective experiences are designed for perception and not for individual senses. This means that experiences and perceptions are contextual, and sensory research and analysis needs to pass through product designers' user research techniques and methodologies before ending up as product features.

With this in mind, we've created some user research approaches for designers seeking to achieve the right mix of multisensory features:

1. Observe the environment.

Take note with all your senses of the environment and whether aspects of it might obscure sensory cues. We designed a medical product a few years ago for which we optimized for both tactile and audible feedback. It turned out the typical user (a surgeon) often blasts music in the operating room, making the audible feedback pretty meaningless.

2. Test with an eye toward cultural and interpersonal context.

With a different medical product, we tested the integration of audible and tactile feedback. The audible feedback was effective at notifying the user the product was fully assembled. However, this was considered unfavorable in this particular context. The user wanted to be discreet while assembling the device, because that information would alert—and possibly alarm—others in the room. (This can be particularly true for cultures where certain diseases are stigmatized.) The audible feedback made it impossible for him to do so.

3. Build sensory info into your user personas.

Designers are great at including info about demographics, interests, brand preferences, and general form preferences in their user personas. One aspect that's usually left out, even though it is never uniform or constant, is a persona's sensory intake profile. But the way people process stimuli—their ability to see and to hear, their tactile sensitivity—changes with age.

And there are always unique factors—someone who's performed physical work for a long time may have calloused hands and lessened tactile sensitivity; the spectrum of audible frequencies narrows with age, and a very effective audible feedback for younger user groups can be completely ineffective for older user groups.

This is what sensory intake information might look like when added to a user persona

4. Lose your sight (or whatever sense is necessary) to walk in your users' shoes.

We've developed a couple of products for users with low-vision. Senses played into those user personas since we were forced to design for senses (tactile, auditory) that are typically non-dominant. We conducted design exercises with designers wearing macular degeneration goggles. We learned that the functional requirements dictated by this impairment changed our perception of how some of the devices' controls should look. Going into the design exercises, we had a hunch that designing for proper usability would trump designing for aesthetic appeal, but we didn't understand the nuances of that until we sat in the users' shoes.

One note: If you know you're dealing with a wide range of sensory profiles, make sure you test and validate for all—you may be tempted to overplay tactile feedback to suit people with limitations. Test to make sure others don't feel like it's over the top.

5. Lose your sight as a matter of habit.

Train yourself to notice the sensory details by conducting "blind evaluations" of competing products during competitive analysis and of your own products and prototypes. Blindfold yourself or better yet, have some other designers evaluate the products without knowing what they are or what they do, and have them evaluate the products' heft, weight balance, and heat transmissivity.

Designers are trained to think visually, and many designers intuitively note other sensory details, but most don't make quantifying it in a systematic way part of their process. Until you make the effort of analyzing based on what you can't see, you can't fully evaluate these other dimensions.

A multisensory footprint chart developed to map products' multisensory signatures during competitive benchmarking

Think of the extensive training and sensory development that goes into becoming an oenologist or a sommelier. Just by looking, sniffing, swirling and tasting a few drops, a wine expert can recognize the year, vintage, region and more. Designers need to cultivate these abilities in regard to products.

Designers are trained to be visually sensitive, but we need to broaden our abilities. In design schools, in design practice, anytime we are evaluating a product, we should be touching it. (Head to brick and mortar stores to shop for personal items—you're missing the opportunity to become a better industrial designer by shopping online!)

Become A Multisensory Design Sensei

The training, practices, and processes of industrial designers need to catch up with the multisensory product features that are becoming more of an everyday reality as emerging technology travels down the cost curve.

All of the ideas in this post—i.e., beginning to develop sensory acuity in design school, adding sensory dimensions to user personas, incorporating the use of a multisensory footprint chart while competitive benchmarking—are gateways to formalizing a user testing and validation process that encompasses sensitivity to the senses.

Read more at Bresslergroup's Accelerator blog: Psych for Product Designers: Research To Inform Multisensory Design.