(dis)comfort questionnaires

Many questionnaires

There are many questionnaires on comfort and discomfort each having their own advantages and disadvantages. Also, the application field and the usage in different design stages have influence on the preference for a questionnaire. For instance the selection of a questionnaire in an exploration phase, where humans have much time to think about options might differ from the one which has to be completed every 10 minutes in a specific testing situation.

Experts’ opinion

In a recent study, 55 experts that visited the International Comfort Conference in 2019 gave their opinion on (dis)comfort questionnaires that are mentioned in the scientific literature. The paper is accepted for publication the journal Work and has the title PCQ: Preferred Comfort Questionnaires for Product/Service Design. The authors are: S Anjani, M Kühne, A Naddeo, S Frohriep, N Mansfield, Y Song and P Vink. In this new paper, we highlight some major outcomes related to (dis)comfort in seat studies and the total environment, though the research covers more application fields such as hand/tool handle design and feet leg studies.

Seat comfort

The most useful questionnaires for seat studies in the early design phase seems to be the seat elements questionnaire published by Van Veen et al (2015). 55% of the 55 experts were in favour of this questionnaire. It consists of 11 questions.  For studying prototypes two questionnaires were suitable. The two that were mentioned most are: the postural comfort method by Corlett & Bishop (1976) (55% favoured for this one) and again the method of Van Veen et al (2015) (64%). For comparing two products both the Corlett & Bishop (1976) and Van Veen questionnaire were favoured, but another one was added: The Mansfied two-stage method described by Sammonds et al. (2017). For evaluating an end product the Van Veen et al (2015) and Sammonds et al. (2017) method were again chosen.

The Van Veen et al. (2015) questionnaire used a 9-point Likert scale for the answers and the 11 questions are:
1.How much would you like to have this seat?
2. How do you assess the comfort of this seat?
3. How do you evaluate the overall comfort of the backrest?
4. How do you evaluate the overall comfort of the seat pan?
5. Does this seat assist your physical well-being?
6. How do you like the mobility of the seat pan?
7. How do you like the mobility of the backrest?
8. How do you like the overall mobility of the seat?
9. How do you like the support of the seat pan?
10. How do you like the support of the backrest?
11. How do you like the overall support of the seat?

In the Corlett & Bishop (1976) questionnaire the participant has to rate discomfort in different body parts at the following body map:

Some authors use a scale for different levels of discomfort per body part.

The Sammonds et al. (2017) questionnaire consists of two stages (see figure below). First the scores for the body parts have to made and then the overall discomfort has to be scored.

Environmental comfort

The most useful questionnaires for environmental comfort in the early design phase could not clearly be defined. All scores were below 50%. Perhaps this might not be so relevant as for various environmental factors guidelines are available. For studying prototype environments, comparing two environments and evaluating environments the Multi factorial methods – cross modal matching ISO 20882 was favoured by 64% of the 55 experts.  This method is not freely available and can be bought from International Organization for Standardization (ISO). Two methods also mentioned for all situations are the ‘simple comfort score’ (used for instance by De Lille, et al, 2016) and the method to measure auditory comfort of Fields et al. (2001).

The method of Fields et al. (2001) is specific for one aspect of the environment and is well described in this paper. The method of the Lille et al (2016) is asking participants to rate their comfort on a scale from 1-10. (1=no comfort at all and 10=extreme comfort). She asked that several times during the flight and could see the pattern in different phases of the flight.

Smell experiment in research fuselage

Part of the project is the construction of a comfort model including all relevant factors, and defining the best way to measure them. In order to discover this, several experiments will be carried out on separate comfort factors or different comfort factors together, in order to reveal their interrelation. One of those experiments on the relation between smell and comfort, was carried out at the Boeing 737-500 aircraft fuselage available at TU Delft, as depicted above.