Design for Intuitive Use - Marsh and Setchi - 2008

8/9/2019 Design for Intuitive Use - Marsh and Setchi - 2008

1/6

Design for intuitive use: a study of mobile phones

A. Marsh, R. Setchi

School of Engineering, Cardiff University, Cardiff CF24 3AA, UK

Abstract

This paper explores the field of design for intuitive use by researching existing ideas and conducting an

experimental study to determine if mobile phones are currently viewed as intuitive to use. In the context of this study,

design for intuitive use is defined as the seamless alignment of cognitive expectation with interface actuality. The

experiment carried out compares mobile phones produced by two large manufacturers, to determine which areas of a

mobile phone facia are commonly viewed to be used for specific tasks and to investigate which image schemata are

used to perform generic interaction tasks. As indicated by the participants in the survey, the Nokia interface is

currently viewed as being very intuitive to use, and their system of interface design has shaped the consumers

expectations of interaction with mobile phones. The experiments conducted showed that the nearer the top of the

keypad a key is positioned, the more important, or regularly used it is expected to be. The most common image

schemata for interaction as indicated by the participants in the experiments are the vertical and depth schemata.

Keywords: Design for intuitive use, intuitive interactions, mobile phones, image schemata

1. Introduction

The term intuitive is referred to regularly in

design, technical fields and by users of products that

require cognitive interaction. Intuition is defined in [1]

as the power of knowing or understanding something

immediately without reasoning or being taught.

Therefore, a product can be intuitive if its functions are

clear and the methods needed to implement them take

little or no cognitive effort. It is apparent that such

products could bring a substantial competitive

advantage to their manufacturers.Design for intuitive use is used to make a process

more efficient when there is more than one path that

can be taken to achieve the same result. A mobile

phone, for example, that responds to the owners

actions in the desired manner would not need an

instruction manual, would be quick to use and would

allow the customer to use the phone as a powerful tool.

This paper aims to explore existing ideas in the

field of design for intuitive use and determine some of

the factors that make a mobile phone intuitive to use.

The experiments conducted are designed to determine

preferred methods of interaction and investigate how

one interacts subconsciously with the physical

properties of a mobile phone.

The paper is organised as follows. Section 2

outlines current research in design for intuitive use.

Section 3 introduces the experimental procedures

employed and the main hypotheses tested. Section 4

contains results and a discussion of the findings.

Finally, Section 5 concludes the paper.

2. Background

2.1. Intuitive interactionThere is a universal agreement that intuition is a

type of cognitive processing that utilises knowledge

gained through prior experience [2], and intuitive use

of products involves utilising knowledge gained

through other experience(s) [3]. Furthermore, an

application is considered intuitively useable if the

users unconscious application of prior knowledge


2/6

leads to effective interaction [4].

Intuition is a term that should not be applied to the

product itself but instead to the link between interfaceand user. As every user is different, so too will be the

level of intuition between the two. A computer mouse

seems intuitive to all computer users, but the first time

user may still need to be shown how to use it.

However, it would be very rare for that person to need

to be shown again. This would suggest that a mouse

becomes intuitive very quickly and this is perhaps the

ultimate aim of an intuitive interface.

It appears that intuition is learnt over time through

use of technologies, so that intuition as the dictionary

defines cannot exist in a designed interface. Instead, an

interface that can be easily learnt has the appearance of

being intuitive. Therefore, intuition is somethingacquired by people whilst using technology, rather than

a standard of technology with which interaction is

effortless.

The methodological tools developed in the area

include the continuum of prior knowledge [5] and the

continuum of intuitive interaction [6].

The continuum of prior knowledge developed by

Hurtienne [5] shows that prior knowledge acquired

before interaction with the new product comes from a

variety of sources. These are classified into 5

categories: innate knowledge, embodied interaction,

culture, expertise, and use of tools. The higher up the

continuum, the smaller the potential number of userspossessing this knowledge; lower level knowledge is

used more frequently. These are the levels that are

more likely to be applied unconsciously and therefore

intuitively.

The continuum of intuitive interaction developed

by Blackler [5, 6] outlines three principles of creating

an intuitive interface:

1. Use familiar features from the same domain,

2. Transfer familiar things from other domains,

3. Increase redundancy and internal consistency of

function, appearance and location within the interface.

Furthermore, each principle is linked to a set of

terms. Principle 1, for example, is compared toinfluencing the interface with body reflectors,

population stereotypes and features from existing

products in the same domain. Principle 2 relates to the

use of metaphors and familiar functions from other

domains. Principle 3 involves using visual and audible

feedback, and providing different ways of doing things

so that both novices and experts, and older and younger

users, can use the same interface easily and efficiently.

Keeping internal consistency allows users to apply the

same knowledge and metaphors throughout the

interface.

Similarly, Hurtienne [4] devises a number of

principles through which to design an intuitiveinterface. These include: suitability for the task,

compatibility, consistency, gestalt laws (how the mind

groups similar elements to an entity, based upon shape,

colour, size and brightness of the elements), feedback,

self descriptiveness, and affordances.

2.2. Cognitive ergonomic: image schema and gestalt

lawsAn image schema is a mental pattern that

recurrently provides a structured understanding of

various experiences. Image schemata can be used

literally, to describe objects or actions, ormetaphorically as a source domain to provide an

understanding of other experiences.

Johnson [7] describes image schema as a dynamic

pattern which functions somewhat like the abstract

structure of an image and thereby connects up a vast

range of different experiences that manifest this same

recurring structure. His list of schemata consists of

twenty seven individual schemata, including centre-

periphery, containment, cycle, path, force, link, part-

whole, scale, and verticality schemata.

Much study of image schema stems from research

in linguistic expressions. The words used to describe

especially metaphorical features, act as a gateway tothe structure the brain has composed to store the

information. It is important to note that the term

image in image schema is not an image that can be

drawn or be shaped in a three dimensional world. An

image schema does not have the rigidity or specificity

of a picture or structure, but consists of parts that can

be flexed and sculpted in an infinite number of ways,

sometimes interacting with other image schema, to

align with perceptions, images and events.

Recently, Hurtienne and Israel [8] suggested the

application of image schemata and their metaphorical

extensions in the design of intuitively usable interfaces.

On creating an interface, its perceived structure shouldtry to fit in as closely as possible to the minds image

schemata. It would appear that the most relevant

schemata for an interface are the cycle schema, path

and end of path schema and verticality schema, whilst

the ergonomics of the interface (e.g. buttons, etc.) will

apply to link schema, force schema and scale schema

(especially with touch sensitive control).

Further studies indicate that the so called gestalt

laws can be applied to image schema [9]. Gestalt is a

German word meaning configuration or pattern.


3/6

Theorists reject the assumption that organization is the

product of learned relationships, but argue that

perception itself is a basic experience. The approachfocuses on the idea of the mind grouping elements to

perceive objects. Generally there are five laws from

which others stem: proximity, similarity, closure,

symmetry and common fate. The gestalt laws are often

applied in product design. Buttons, for example,

grouped together are perceived as having similar

functions.

These theories indicate that to teach a mind how to

use something, it is the information presented to it that

will determine its success. Going further, the success of

this information resulting in the correct cognitive

response lies in the similarity of the image schema

formed whilst receiving information and the imageschema used to implement interaction. Image schemata

are flexible structures for the mental organisation of

experiences and comprehension.

3. Experimental procedures and hypotheses

3.1 Questionnaire

The current style of phone sales from a high street

network store typically offers a free mobile phone

handset when a pay monthly tariff is purchased. These

tariffs typically last for 12 or 18 months and after this

time, a new tariff is sold, normally resulting in a newhandset. Therefore, the vast majority of the population

is expected to have owned their phone for a short

period of time and to have had a number of phones in

the past.

This style of selling results in the user making their

way through a high number of phones in a relatively

short period of time and also forces them to potentially

learn a new interface every year or so. The user may, to

make things easier, repeatedly choose the same phone

manufacturer to replace the old handset whilst new

technologies, appearances and styles are most probably

the main factors that would cause the user to choose a

new phone manufacturer. Users may have the ability tobe in contact with the new handsets from peers, so

when it is time to choose a new handset, the buyer may

have already done a little market research and have

made the decision for their new phone before walking

into the store. The factors discussed here will become

apparent, or disproved by the correlations between the

handset currently used and those that have been used

before.

The questionnaire published in [10] also contains a

set of questions designed to find out how mobile

phones are used. It is hypothesised that calls will rank

the highest score for use, and the camera will score

highly as well. It is not expected that internet and e-mail will have high scores as these are still relatively

new technologies for the mobile phone and most

people will have a computer linked to far faster internet

at home. Games also, are expected to score low, simply

because the youthful users, less than 17 years of age,

have not been included in this survey due to ethical

reasons.

The awareness and ability sections of the

questionnaire will unveil how confident users feel

about their current phone. Phones with a high

awareness score may have an open feel to their

interface, where most of these features will be on

display at the same time, increasing awareness, mostprobably in the main menu field. A high score will

naturally appear if the user actually uses all the features

of their phone. In theory, the ability score should not

exceed the awareness score, as awareness must be

present before one can have the ability to use a feature.

There may however be some confusion here and

perhaps pride also, where the user may rank their

ability to use all the features they regularly use. The

ease of learning ones current phone is a direct score

for specific manufacturers and will be analysed as

such. If the hypothesis of most phones being owned for

1 or under years is true, then this question holds a great

significance as the early learning stages may still befresh in the users mind.

3.2 Experiments

The experiments involve a visual test with two

schematics of simplified button configurations; one

based on the Nokia system, and the other, based on the

Sony Ericsson system (Fig. 1), which also holds

similarities to the Motorola and Samsung systems

along with the iPod. The test is videoed with a digital

camera. The aim is to determine what keys, or areas of

the mobile phone facia are most commonly viewed to

be used for specific tasks and to investigate if there areany consistencies with the methods required for

existing phones and these schematics.

Participants are informed about the scene in front

of them: You have in front of you a simple schematic

of a phone facia. The visuals, key notation and screen

interface are entirely that of your choice. You are

currently at your home screen with a locked keypad.


4/6

Fig. 1. Nokia and Ericsson schematics used in the test.

The participants are then asked to perform the

following tasks, on each configuration one at a time,

using the schematics in any way they saw fit.

1. Unlock the key pad.2. Press the menu button;

3. Open the text message folder and select write

new message.

4. Go back to the home screen.

5. Key in the number 07856.

6. Delete the 6 and type a 2.

7. Delete all 5 numbers.

8. (Are you at the home screen?)

9. Find your contacts.

10. Scroll down 5 names.

11. Scroll up 3 names.

12. Call this number.

13. Hang up.14. Lock the key pad.

The results from this task are used to determine

any consistency in the areas used for locking and

unlocking the keypad, menu, select, back, number

keys, delete and scroll down, scroll up, call and hang

up.

It is hypothesised that there should be no problems

with typing of numbers due to the repeated constant

standards of these keys being placed at the base of the

keypad with the ordering of 1 top left and 9 bottom

right with *, 0 and # along the bottom row. The Nokia

schematic may cause more inconsistencies than the

Sony Ericsson schematic as the only variable in theformer is position, with identically sized and shaped

keys, thus removing most of the gestalt laws. The

results from this test may therefore indicate broad

similarities in desired positions of keys only.

Having the round shape in the top central position

of the Sony Ericsson schematic bares a far closer

resemblance to the items from which this schematic has

been derived, and may cause initial recollection of past

experiences with such items. If this is the case, it would

be expected that each test on this schematic will result

in similar patterns of interaction.

This schematic has a clear divide of the regular

shaped keys at the bottom from those above. Thisfactor leads to a hypothesis of the bottom keys being

used only for number typing whereas the top group will

be used for interface manipulation, without any cross

over. It will be interesting to see how many people use

the circular shape as a wheel, in a similar manner to

the iPod. None of the mobile phones widely available

on the current market use this system, but the iPod has

become such an iconic example of a portable electronic

device that some subjects must make this link.

4. Results and discussion

A total of 46 completed questionnaires werereturned and analysed. Only one of these participants

did not own a mobile phone. The average was 28 years

of age. There was a fair spread of age range; however

the greatest number of responses was from those in the

21-24 age range. On average, each user had owned 5.5

phones in their time. Text messaging had 33% of the

score for use of the mobile phone, and calls had 32%.

The final third was split between all other uses

displayed in the questionnaire. Nokia dominated the

past market share with 49%. Sony Ericsson and

Motorola shared the runner up spot, holding 15% of

past sales. However, of currently owned phones, Nokia

and Sony Ericsson share the top spot with 32% eachand Samsung took the third spot with 16% as Motorola

dropped to forth with 12%. Participants gave

themselves average scores of 3.4, 3.2 and 3.6 of a

possible 5, for phone awareness, ability to use all

features and ease of learning current phone

respectively.

74% of all questionnaires were completed by

persons less than 24 years of age. Therefore, the results

are primarily indicative of the perceptions of students

in this age range. This generation has grown up

surrounded by technology from a relatively young age,

with their ownership of their first mobile phone at an

average of 13 years of age. The student will have ahigh social use of their mobile phone, the possibility of

higher peer pressures to keep up to date with styles and

technology, a fair amount of free time, but less free

cash flow and are open and perhaps naive to special

marketing techniques, which are used to target the

student customer base. In contrast, results from a

working business person would differ greatly from the

student results with less free time, so probably more

calls than texts, higher specification, the ability for

more expensive handsets and business tariffs, perhaps


5/6

even paid for by the employer. The results gathered

from older generations can be used as a slight

comparison, but no claim is made that the perceptionsof these generations are properly represented.

Almost 60% of those asked said they still used

instruction manuals. This question was asked before

the mention of a mobile phone, but the results indicate

that either the user is not willing to trust their existing

ability with technology, or the majority of devices are

still too complicated to use on first experience. This

suggests that there is much scope for improvement in

the way technology presents the way it should be

interacted with, removing the need for instruction

manuals.

Mobile phones have been used by those asked for

an average of 6.8 years, with an average of 5.5 phonesbeing owned in this time. This positively correlates

with the result of 55% of the participants having owned

their current phone for less than 1 year and a total of

87% for 2 years or under. This result follows an

exponential decay profile, showing that future sales of

mobile phones have the opportunity to continue to soar

as they are currently doing so. If this influx of new

phones to the population continues, they will have an

even greater effect on shaping how one interacts with

technology than this study will show.

The average score of 3.4/5 (70%) for phone

feature awareness is a good score, but with the low use

scores for the newer features, this suggests that amobile phone is still essentially a speech and text

communicator between individuals. Over half of the

sample gave themselves, perhaps modestly, a score of

4/5 for their ability to use the features available. This

suggests that phones are generally well mastered by the

sample, however, all five participants to give a score of

1 for this question was less than 24 years of age, and

all owned a Nokia mobile phone. Nokia did however

score a remarkable 4.7/5 score for ease of learning

the current phone. Sony Ericsson had the only two 1/5scores for ease of learning, but overall scored a second

place average of 3.4/5.

Eight subjects took part in the visual experiment.

On average, the experiment took a total of 10 to 15 min

for the participant to complete. All of them carried out

the tasks on both schematics. The Nokia schematic had

a success rate of 50% for the correct interaction being

carried out for the respective task. The Sony Ericsson

scheme achieved 61%. Fig. 3 and Fig. 4 show the

results for tasks unlock the keypad and press the

menu button, where the colour scheme and the

numbers indicate how many participants have used the

same pattern. All results are published in [10].It has been shown that the nearer the top of the

keypad a key is positioned, the more important, or

regular to use it should be. These buttons are currently

used to interact with the software of the phone, whilst

the number pad should be exclusively used for number

and text and positioned on 12, identically sized and

shaped keys in a 3x4 arrangement. Future mobile

phone design should keep this system to appear to be

intuitive to use. Unlocking and locking a keypad

should involve two keys, at opposite ends of the

keypad, adapted from the Nokia system and menu

should be located top left or top centre. This key

should also double up as the select key when in a menumode. There is no preferred side to locate a back

button, but it should not be placed in a central position.

The function of a delete key should be clearly marked

as there is no preferred choice of position for this

function. Scrolling should be given a top central

position, with a vertical alignment. Call should always

be on the left hand side and hang up on the right.

Experimental results (Nokia

schematics)

Experimental results (Sony

Ericsson schematics)

Correctly executed task

(Nokia schematics)


(Sony Ericsson schematics)

Fig. 3. Task unlock the keypad.


6/6

Experimental results (Nokia

schematics)

Experimental results (Sony

Ericsson schematics)


(Nokia schematics)


(Sony Ericsson schematics)

Fig. 4. Task press the menu button.

5. Conclusions

This study confirmed that intuitive use involves

the seamless matching of cognitive expectation with

interface actuality.

The participants in the study have shown that

Nokia have set a very high standard of intuitive use

for the mobile phone, that other manufacturers are

trying to match. Even with an unmarked, limited gestalt

arrangement of keys, 50% of all interactions asked to

be carried out on the schema would have been

successful. Sony Ericsson, with a starkly different

scheme, where gestalt laws are far more eminent had

the higher score with a 61% successful interaction rate.However, Sony Ericsson were only given a 3.4/5 score

for ease of learning whilst Nokia have clearly set the

standard with a 4.7/5 score. This early appreciation of

ease of use must have played a key factor in Nokias

early domination of the market, but now other

manufacturers have learnt this fact and are far closer

competitors to Nokia than just a few years ago.

The mobile phone, when used as a voice and text

message communicator, is generally a very successful

product in terms of being easy to use. The majority of

phones are based on one of a few classic styles and

there has been much pressure from the consumer for

these devices to be intuitive to use. However, phonemanufacturers have a delicate time ahead of them as

the era of the mobile phone in a pure sense is over.

New technologies are changing the function of the

mobile phone and currently these new functions appear

to be confusing to use on such a small device. This

justifies research into design for intuitive use in the

future as many different devices, along with their

respective styles of interaction, are fused together into

what is currently the mobile phone.

References

[1] Oxford English Dictionary, Oxford University Press,

2005.

[2] Blackler A. L., Popovic V. and Mahar, D. P.

Empirical investigations into intuitive interaction: a

summary. MMI-Interaktiv, 2007, vol. 13, pp. 4-24.

[3] Blackler A. L. and Popovic V. The nature of

intuitive use of products: an experimental approach, Design

Studies, vol. 24, 2003, pp. 491-506.

[4] Mohs C., Hurtienne J., Israel J. H., Naumann A.,

Kindsmller M. C., Meyer H. A. and Pohlmeyer A. IUUI -

Intuitive Use of User Interfaces. In: T. Bosenick M.

Hassenzahl M. Mller-Prove and M. Peissner (Eds.),

Usability Professionals 2006, Stuttgart, German Chapter der

Usability Professionals' Association, 2006, pp. 130-133.

[5] Blackler A. L. and Hurtienne J. Towards a unified

view of intuitive interaction: definitions, models and tools

across the world, MMI-Interaktiv, 2007, vol. 13, pp. 37-55.

[6] Blackler A. L., Popovic V. and Mahar, D. P.

Towards a design methodology for applying intuitive

interaction, In: Friedman, K., Love T., Crte-Real E. and

Rust C. (Eds.) Proceedings WonderGround: 2006 Design

Research Society Int. Conference, Lisbon.

[7] Johnson M. The body in the mind: The bodily basis

of meaning, imagination, and reason. Chicago: University of

Chicago Press, 1987.

[8] Hurtienne J. and Israel J. H. Image schemas and

their metaphorical extensions: intuitive patterns for tangible

interaction. In: 1st International Conference on Tangible and

Embedded Interaction (TEI'07), Baton Rouge, ACM Press,

2007, pp. 127-134.

[9] Hurtienne J., Weber K. and Blessing L. Prior

experience and intuitive use: image schemas in user centred

design, In: Designing Inclusive Futures, Springer, London,

2008, pp. 107-116.

[10] Marsh A. Design for intuitive use, Final Year

project MMM 130, Cardiff University, UK, 2008.
http://www.springerlink.com/content/v4g55u/?p=5b234894029b47438bf355acf84a6c62&pi=0http://www.springerlink.com/content/v4g55u/?p=5b234894029b47438bf355acf84a6c62&pi=0

Design for Intuitive Use - Marsh and Setchi - 2008

Documents

Transcript of Design for Intuitive Use - Marsh and Setchi - 2008