user interface design -- an experimental study

American Society For Cybernetics Washington DC, 27 - 30 October 2005.

User Interface Design -- An Experimental Study

John Pourdehnad, et al.

Ackoff Center for Advancement of Systems Approaches (ACASA)University of PennsylvaniaPhiladelphia, Pennsylvania


User Interface Design -- An Experimental Study

Barry G. Silverman1

John Pourdehnad1

Gnana Bharathy1

Melanie C. Green2 Joyce A. Salisbury3

1Ackoff Center for Advancement of Systems Approaches (ACASA), University of Pennsylvania2Department of Psychology, University of Pennsylvania3Market Research, General Motors Corporation -- GM


Introduction

Americans are going online to conduct such day-to-day activities as business transactions, personal correspondence, research and information gathering, and shopping.

It is no longer good enough to rely on generalized visual library and hypermedia principles to support all these activities as if they were the same.

There has been little time to study these designs and how they impact consumers.


The Challenge

It is vital to develop a better understanding of how web designs facilitate consumer needs (or not), and to assess the role of individual differences and whether designs that reflect such differences provide improved service.

There are many consumer-oriented websites, yet the science of website design is relatively immature.

There are few scientific principles upon which to base such designs, although many designs are used in practice.


The Research

A number of different approaches to user interface design improvements were considered.

Of the various possible approaches to human computer interface (HCI) design, the most common practice in the past, and to a great extent today, is to assume one uniform user group with similar characteristics, needs, and preferences.

– This approach usually requires an iterative design procedure to minimize the differences between users and the system.

Another design approach is to assume different user groups with different characteristics, needs, and performances who will be using the system.

– This approach requires a careful examination of the population in order to identify such groups, as well as different interface modules for the same service/product.

The approach taken in this study was to assume a null hypothesis that there are no differences among the users (although our belief is the opposite) and to try to disprove that theory. For this purpose, the following research tasks were embarked on:


Research Tasks

Development of a model to study HCI (this entailed creating a structured model of the intended user),

Development of instruments for measurement, Validation of the instruments, Application of instruments to test the model, Analysis of the results obtained through the application of the

model, and, Development of recommendations for the use of the model.


Development Of A Model To Study HCI

We examined individual differences that were relevant to human computer interaction. Furthermore, we investigated possible methods of evaluating these differences.

These differences can be categorized as:– Physiological: Cerebral Hemisphericity, Vision, Hearing, and

Mobility/Dexterity

– Psychological: Intelligence, Cognitive Style, and Personality

– Sociocultural: Language, Culture, and Environmental From the above list we have determined that the most important

category for the current ACA website challenges is the Psychological


Furthermore, we decided that an examination of cognitive differences was in order, based on initial findings from secondary research (literature review) that suggest that they are the most significant with regards to human computer interaction.

However, in our research and consultation with subject matter experts, we found that Need for Cognition, rather than cognitive style, can be a vital factor.

Need for cognition (NFC) is an individual difference measuring how much people like to think. It is a motivational variable, and should not be confused with cognitive ability or intelligence

The dynamic that we were overlooking was preference (motivation) to purchases; specifically, the differences between those individuals characterized as Utilitarian (focusing on practical aspects of a purchase) vs. those characterized as Lifestyle seeking (wanting to convey a particular image or impress others through a purchase).

Development Of A Model To Study HCI (Continued)


With these two dimensions, it was possible to hypothesize a two-by-two matrix with the following four quadrants or cells: – Low Need for Cognition/Utilitarian Oriented,

– Low Need for Cognition/Lifestyle Oriented,

– High Need for Cognition/Utilitarian Oriented, and

– High Need for Cognition/Lifestyle Oriented.

Development Of A Model To Study HCI (Continued)

LL HL

HULU

Lifestyle

Utilitarian

Low Need forCognition

High Need forCognition


Formulation Of The Hypothesis To Be Tested

In summary, we would like to confirm whether the web users could be segmented into one of four cells in the matrix shown above

In order to test this, we have formed the following hypotheses:

Null Hypothesis(H0):

Alternative Hypothesis

(Ha):

There is no statistically significant difference in the need for cognition and preference function scores of the people between the four classes (quadrants). That is, the variances within the classes are not significantly smaller than the variance between the classes

There is a significant difference in the need for cognition and preference function scores of the people between the four classes (quadrants). That is, the variances within the classes are significantly smaller than the variance between the classes.


Development Of Instruments For Measurement

As a measure of Need for Cognition, we used the Need for Cognition Scale in Petty et.al. (1984): 1. I would prefer complex to simple problems.

2. I like to have the responsibility of handling a situation that requires a lot of thinking.

3. Thinking is not my idea of fun.

4. I would rather do something that requires little thought than something that is sure to challenge my thinking abilities.

5. I try to anticipate and avoid situations where there is likely a chance I will have to think in depth about something.

6. I find satisfaction in deliberating hard and for long hours.

– For the preference function dimension, there is no existing instrument. Instead, we had to construct our own questionnaire that would allow us to identify an individual’s preferences that form the basis for their purchasing decisions based on their orientation towards utility or lifestyle.


Lifestyle Oriented Need for Feeling (LF): someone with a high need for emotional attachment to a product.

Need for Form (LF): someone with a high need for aesthetics and style.

Need for External Status (LE): someone with a high need to feel wanted, loved, and cared for by a peer group.

Need for Internal Status (LI): someone with a high need for approval, good opinion, and

regard

Utilitarian Oriented Need for Function (UF): someone who focuses on the actions and activities assigned to, required of, or expected of a product.



I purchase things I love (LF) I want to be liked by others (LI) I buy things that I like, regardless of current trends (UF) I often purchase things I don't need (UF) I compare myself to others (LE) What you think of yourself is reflected by what you wear (LI) I choose products based on look and feel (LF) I'm not as concerned about fashion as I am about wearability (UF) I like to impress my peers (LE) I like form over function (UF) I like belonging to groups or organizations (LE)



Survey

GM then administered the on-line survey to the following groups of potential customers: – Group I consisted of 112 participants of 2 general GM online communities

(CCO/CCOC) set up to conduct market research. They are new vehicle shoppers and are approximately 50% male and 50% female, with half under the age of 45 and half 45 and older. The sample is all from the Los Angeles, California area., and

– Group II consisted of 69 consumer, also part of a GM online community (CEO), who are interested in cutting edge technology, alternative fuels, hybrid vehicles, or the environment. This group has higher income and more education that the traditional new car shopper.

– The sample is also skewed approximately 75% male. In addition, the participants in this group are willing to pay at least $35K for a hydrogen-powered vehicle at the point of recruitment. Half live within 100 miles of Los Angeles, CA and the other half live within 100 miles of Philadelphia, PA (with a few outliers)


Results

Results of the Survey for Group I

14

24

34

44

54

64

18 28 38 48 58 68 78 88

Need for Cognition

Pre

fere

nce

Fu

nc

tio

n

Low Need for Cognition / Utilitarian Oriented

High Need for Cognition / Utilitarian Oriented

Low Need for Cognition / Lifestyle Oriented

High Need for Cognition /Lifestyle Oriented


Results

Results of the Survey for Group II

14

24

34

44

54

64

18 28 38 48 58 68 78 88

Need for Cognition

Pre

fere

nce

Fu

nc

tio

n

Low Need for Cognition / Utilitarian Oriented

High Need for Cognition / Utilitarian Oriented

Low Need for Cognition / Lifestyle Oriented

High Need for Cognition /Lifestyle Oriented


Number Of Subjects Categorized Into Each TypeUsing Short Survey

Typology

# of Subjects

Group I Group II

LU 20 36

LL 43 10

HL 32 22

HU 9 1

Total # of Subjects 104 69


Application of the Model to Solve the Problem

Differentiating the Web Interface based on Typology By studying the unique needs of individuals in each cell, six design

criteria were identified and, based on the secondary research, requirements for each website interface were developed.

Based on the characteristics developed for each cell, four mockups were designed whose overall aesthetic and usability should attract, satisfy, and retain the users in each designated cell, though this remains to be more fully evaluated by future research. – For that, as mentioned earlier, we propose to use focus groups to

collect assessments of and refinement ideas for the design mockups presented in this section.

The merits of the four different mockup designs were preliminarily examined and as a result three new web user interface options were developed for possible structures including screenshots and a brief description. – It is possible to demonstrate that with any of these options a user can

obtain the necessary assistance in selecting a vehicle while providing valuable information to the organization.


High Need for Cognition (H):

An individual who is highly analytical and enjoys being presented with a lot of data and the opportunity to process that data. It seems reasonable to conclude that these people prefer charts and graphs.

Low Need for Cognition (L):

An individual who focuses less on analytical tasks and prefers not to be overrun with data. It is likely that these people prefer pictures and audio representations.

Lifestyle Oriented or High Preference Function Score (L):

Someone who believes that the value of a thing depends on how it reflects the person's values and preferences.

Utilitarian or High Preference Function Score (U):

Someone who believes that the value of a thing depends on its practical usefulness.

Design Tailored Interfaces To The Cognition Needs And Preference To Purchases


Guidelines for User Requirement

Categories Low Cog/Utilitarian Low Cog/Life Style

High Cog/Life Style High Cog/Utilitarian

Text or pictures Pictures Pictures Charts Charts

Options presentation Traditional Options Collection of Products

Graph of Value Graph of Options

Persona preference Comedy/Wacky Alien (Alf)

Secret Agent Butler/Celebrity (Paul Newman)

Abstract Narrator (Hal 9000)

Complexity Sorting info/nonlinear Presented info/linear

Presented info/linear Sorting info/nonlinear

Final action Place car in virtual “garage”

Drive car away/get in

and go

Have car delivered Add car to garage

Preferred imagery - classic look- pictures of the product in

use

- extreme look- pictures of

gaudy and sexy people posing with

product

- art/design look- customization of product- prefer to see car in

intended environment

- non artsy look- cut-through diagrams of

product


Differentiating The Web Interface Based On Typology

By studying the unique needs of the individuals in each cell, we hope to create four website interfaces whose overall aesthetics and usability will attract, satisfy, and retain the users in each designated cell.

If this is successful, we will confidently be able to create an “adaptable” website that will effectively cater to all potential audiences.

To this point we have mockups of all of the different cells. Our framework follows the guidelines laid out in Table below:


Introduction Pages For Each Type


The Low Cognition/Lifestyle


The High Cognition/ Utilitarian


The Low Cognition/Utilitarian


The High Cognition/ Lifestyle


Development Of Recommendations For The Use Of Models

Option #1: This option entails the use of a survey technique and the immediate direction of a visitor to the HCI that corresponds to the appropriate cell based on the survey. Upon completing the survey, we envision that a visitor would be directed to the appropriate introduction page and follow along with one of the enclosed sets included in previous slides.

Option #2: This option would present the visitor with all four options for each step along the way and would allow the user to select the desired interface for each step along the way. This method calls for a display much like that seen above for each step in the process from Introduction to a final analysis of one particular vehicle.

Option #3: This option is based on an extension of what we have seen recently on such services as America Online and MSN. This option allows the user to use the designated interface as prescribed by some survey or self-selection technique, but also allows the individual to switch to one of the other available options in the event that they choose to do so, yet does not force a choice at each step.


Further Research Questions

To undertake additional research to support the premise that different categories of individuals should be presented with different interfaces;

To develop an improved way of determining the user’s profile; To determine an exact design for the interface, using focus groups;

and To develop an associated decision support system for each

interface.

user interface design -- an experimental study

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