A Comparative Usability Evaluation of User Interfaces for Online Product Catalogs

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A Comparative Usability Evaluation of User
Interfaces for Online Product Catalogs

• Ewa Callahan Jürgen Koenemann
• Presented by Xiaohong Bao

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Introduction

• A comparative study of the usability of
  hierarchical structure and Infozoom
• The increase in electronic commerce creates a
  need for Electronic Product Catalogs (EPC).
• Navigation problems are the second most cited
  reason for not shopping online.

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Introduction ---contd

• The most common catalog interfaces on the web are
  hierarchically organized catalogs.
• Problems
• Confusing
• Items in dropdown menus are not visible
• Lengthy result pages force users to scroll
• Solutions
• Recommendation approach
• Interaction approach

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Evaluation of existing online catalogs

• List of Websites Evaluated (Fall 1999)
• 1. www.autobytel.com 2. www.Auto.de
• 3. www.autoinfo.de 4. Automarkt
• 5. www.auto-shop.de 6. www.autosite.com
• 7. www.autotaal.nl 8. carpoint.msn.com
• 9. www.dadb.com 10. www.faircar.de
• 11. Lycos Decision Guide Cars 12. Mastercar.de
• 13. www.mobile.de 14. www.whatcar.co.uk

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Evaluation results
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Result analysis

• Database size
• Searching mode
• Attribute
• Specifying ranges
• Searching history
• Result pages
• Sorting search results
• Item comparison

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Infozoom introduction

• Based on dynamic queries and fisheye techniques
• Attributes as rows and objects as columns
• Compressed mode and overview mode
• Many ways of searching
• Easy to compare, sort and re-order the results

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Overview Mode
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Compressed mode
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Usability study

• From the feature comparison of Infozoom and the
  hierarchical interface, Infozoom should be more
  efficient
• A comparative usability study to confirm it

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Materials

• A database contains 1690 cars with over 20
  attributes.
• The hierarchical interface was implemented with
  forms in MS Access.

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Hierarchical interface-1
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Hierarchical interface-2
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Hierarchical interface-3
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Participants

• Totally 26 participants
• 15 male and 11 female
• 13 aged 2130 9 aged 3140 one teenager and one
  over 51
• 16 use computers over 10h/week 6 39 h/week 4
  less than 2h/week

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Tasks

• Find Attribute value for given Object
• T1 Does the Jaguar XJR have side airbags?
• Find Database SubSet Attribute Value
• T2 How many different models does the Peugeot
  class 106 have?
• T4 How many cars have the following
  characteristics
• convertible, 100-150 HP, front drive, and cost
  40.000 DM or
• less?
• For given Attribute(s) value(s) Find Object(s)
• T3 Which middle class car is the cheapest one in
  the database?
• T6 Which Funcar has the quickest acceleration?

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Tasks-contd

• Compare Attribute Values for 2 Objects
• T5 Which car has better fuel consumption the
  Audi A6 1.8 or the Volvo S70 2.0?
• Find Database Attribute Value
• T7 How many cars are in this catalog?
• Compare Attribute Values for Subset
• T8 What is the price range (from the cheapest to
  the most expensive model) for the Alfa Romeo 145
  series?
• T9 Is the acceleration of the Mercedes-Benz S430
  Automatic slow, normal, or quick for a car of its
  class?

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Procedure

1. Introduce the purpose and upcoming tasks briefly
2. 5 minutes demo about Infozoom
3. Introduce 9 tasks. After each task, they answer 3
   questions about the satisfaction, perception of
   the time needed, perceived efficiency
4. Summarizing their experience

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Results

• Accuracy
• Completion time
• AVGIZ 19.4 min / AVGHI 27.7 min
• Navigation
• Ease of use IZ 5.5 / HI 4.9 over 7
• Efficiency IZ 5.0 / HI 4.8
• Satisfaction
• Comfortable IZ 5.15 / HI 5.23
• Fun IZ 6.3 / HI 5.0
• Overall satisfaction IZ 6.38 / HI 5.38

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Completion rate and accuracy
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Observations

• Users strategies
• Critical incidents --- breakdown and things that
  went especially well
• Users comments

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Hierarchical interface

• Dislike look for desired information from main
  menu
• Be lost on pages that looked like
• Be annoyed by the long pull-down menus and
  lengthy result pages
• Be confused about the default values and
  attributes visible
• Be inpatient about no car matched

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Infozoom Interface

• Feel overload at the first glance
• Hard to choose appropriate search strategy at the
  beginning
• Difficult to double-click on the small sectors if
  selecting objects on the screen

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Conclusion

• Both EPCs interfaces were rated highly, but
  Infozoom was rated higher in overall performance
• Infozoom supports choice by attribute searching
  strategy better
• Infozoom interface has easy learnability