Do Metaphors Make Web Browsers Easier to Use

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Do Metaphors Make Web Browsers Easier to Use?

• Article author Elissa D. Smilowitz
• Presented By Ofir Germansky

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Preview
INTRODUCTION MOTIVATION
EXPERIMENT 1 Do Metaphors Aid Performance?
EXPERIMENT 2 Composite Metaphor
CONCLUSION
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What Is A Metaphor ?
INTRODUCTION
Metaphor (Britannica)figure of speech that
implies comparison between two unlike entities,
as distinguished from simile, an explicit
comparison signaled by the words like or as.
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Example, Connected Acyclic Graph presented as a
tree
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Metaphors and Technology

• Metaphors are widely use in many user
  interfaces of todays computer.
• Software designers are using metaphors in a
  variety of software from operating system to
  information retrieval application.

Explorer metaphor describes a tool for searching
files
The mail metaphor for sending a message over the
WWW
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• Technological advances have created more and
  more realistic description of these metaphors.
• However, the technological improvement doesnt
  ensure the utility of the psychological effect of
  the metaphor.

TV/VCR metaphor for media player old VS new Is
the new easier to use ?
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Motivation

• The advantages of metaphor in the design of user
  interface are the same in education.
• In education giving students a comparison can
  help them learn.

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Comparison Example 1 Electricity is like water
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Comparison Example 2 Storage location as
buckets
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Effectiveness of metaphors

• Research has shown that many programming
  constructs in a programming language could be
  learnt more easily when they were presented in
  the context of a concrete metaphor.

A concrete metaphor ACCELERATOR is used to
create a shortcut (like CtrlS) to a UI menu in
MFC Visual C application.
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Educators in many domains believe that students
can import conceptual relations and operations
from one domain to another.
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An open question How to use metaphors?

• Research has demonstrated that there may be great
  value to teaching about existing computer systems
  through the use of metaphor. Yet, little research
  has been conducted as to how to design a user
  interface around a metaphor.
• Question Do metaphors provide the same
  advantage in the domain of user interface design?

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Metaphor in current UI

• In desktop operating systems, routine file
  management tasks become familiar operations on
  familiar objects such as getting a folder from a
  file cabinet .

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• These systems frequently carry the metaphor
  even further by displaying documents as paper
  from the file (directory) which is taken out from
  the cabinet (hard disk), and showing simultaneous
  activities in separate places like stacks of
  papers on a real desktop.

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Lack of research
Many guidelines encourage the use of interface
metaphors and many interface metaphors are
employed today. But there is a lack of research
in the following subjects

• The effects of metaphor on users performance
  with a computer system.
• Is it beneficial to use a metaphor .
• how to design the most effective metaphor.
• what characteristics enhance the power and
  utility of interface metaphors.

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Main goals of this research

• Understand how metaphors can improve users
  performance.
• Identify the characteristics of metaphors that
  make them more useful.

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Introduction for the experiments

• This series of experiments demonstrates a
  performance advantage provided by UI metaphors
  compared to non metaphoric interfaces.
• The findings also identify some of the
  characteristics that contribute to the
  effectiveness of a metaphor.  

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Application domain for the experiments

• The World Wide Web was chosen as the application
  domain in which to study UI metaphors.
• Several alternative user interfaces were designed
  based on the task of searching the World Wide Web
  for information.
• Thus, the following studies also provide a
  practical direction for the design of an
  effective metaphoric interface for exploring the
  Web.

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Some notes about those experiments

• The article is quite old, approximately 10 years
  old, in the time when the WWW wasnt so popular.
• The computer used for this test was 486, which is
  the predecessor for the Pentium I machine
• The Software application for searching
  information in the WWW is Mosaic, which is the
  predecessor to the Microsoft internet explorer
  which is based on NCSA Mosaic.
• Still it can be used as a model for people who
  are non-WWW-literate.

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EXPERIMENT 1DO METAPHORES AID PERFORMANCE ?
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Introduction
The experiment goals are

• Establish if metaphors do in fact improve users
  performance.
• Find out how to create a UI metaphor.
• Find the relation between the subjects of
  education (and linguistics, philosophy) to a
  UI metaphor. Because there is a lot of
  work in those subjects about metaphor which might
  help us create and use a UI metaphor.

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Introduction Graphics in metaphor

• In a graphical user interface,
  it is commonly assumed that UI
  metaphors are carried
  both by
  the terminology and graphics.
• many people incorrectly assume that a UI metaphor
  cannot exist without the presence of graphics.
• While it may be that the metaphor is much more
  compelling and apparent if incorporated into the
  interface graphics, it is certainly not a
  defining characteristic of a metaphor.
• Examples of non-graphic metaphor are the DOS
  commands copy, delete and etc.

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Subjects

• Forty undergraduate students at New Mexico State
  University participated in partial fulfillment of
  an experimental credit requirement in
  introductory psychology.
• All subjects had used a computer mouse before but
  none had prior experience with any World Wide Web
  browser.
• The forty subjects were
  randomly divided between
  each of
  four experiments.

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Materials

• The experimental paradigm was based on the
  Mosaic software application used to search for
  information on the World Wide Web.
  

All subjects performed tasks on an HP Vectra
486/66 XM personal computer with a VGA
resolution color monitor.
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• Terminology
• for the two non metaphoric experiments was based
  completely on Mosaics function names.
• for the two metaphor experiments was based on a
  library metaphor.
• The library domain was chosen because its primary
  function of searching for information is
  analogous to the primary task performed in Mosaic
  that of searching for information on the World
  Wide Web.

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Function labels used in No-metaphor and
Metaphor experiments
                        
                      
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Design

• There were four experiments which differed
  in the interface terminology
• Subjects in first experiment saw library metaphor
  terms along with icons representing a library.
• Subjects in the second experiment saw the
  metaphor terms but with no icons.
• Subjects in the third experiment didnt see the
  metaphor terms but saw icons.
• Subjects in the forth experiment didnt see
  neither metaphor terms nor icons.

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Example task in experiment with metaphor
With icons
Without icons
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Example task in experiment without metaphor
With icons
Without icons
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Tasks Structure

• All subjects performed 3 blocks of 10 tasks per
  block.
• Task structure was identical across all three
  blocks
• the specific tasks were slightly different.
• Task order within block and block order were
  randomized.

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Measure

• Three dependent measures were collected for each
  subject
• 1. Task time
• task time was measured in seconds from the start
  of the task until the completion of the task.
• 2. Number of errors
• number of errors, was calculated by subtracting
  the minimum possible number of mouse clicks to
  successfully complete the task from the actual
  number of times the subject clicked the mouse
  button on an icon or label.
• 3. Task completion
• the task completion dependent variable was based
  on successful completion of the task. If a
  subject exceeded 25 clicks on a particular task,
  the task would be terminated and the subject
  would be allowed to move on to the next task.
• An experimental session lasted between 30 minutes
  and 1 hour.

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Procedure
Before the experiment

• Subjects were asked to fill out a questionnaire
  which asked about their computer background.
• Subjects were then given written instructions
  about the computer tasks they would be
  performing.
• All subjects were shown a picture of what the
  computer interface would look like.

• Subjects in the two metaphor experiments were
  told that the metaphor is based upon a library,
  and thinking about a library would help them to
  search for information.
• Subjects in the two no-metaphor experiments were
  told that the basic task was to search for
  information.

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During the experiment

• The subjects performed a series of thirty tasks
  on the computer.
• Subjects read the task in an area on the computer
  screen and then tried to figure out how to
  perform the task.
• When subjects correctly performed the task they
  would be given auditory and visual feedback, and
  allowed to continue to the next task.
• If a subject exceeded 25 clicks on a given task,
  they were shown a message to that effect and
  allowed to continue to the next task.

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Completion of the experiment

• Upon completion of the thirty tasks, subjects
  were asked to fill out a questionnaire concerning
  their preference for the interface and
  terminology.
• Subjects in the two metaphor experiments were
  also asked to rate how much the metaphor
  helped them perform the task.

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EXPERIMENT 1 RESULT AND DISCUSSION
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Performance Measures

• In total, each subject completed 3 blocks of 10
  tasks in one of four experiments.
• Statistical model used for the measures
• ANOVA (analysis of variant)
  tests for significant differences between
  means.
• Chi-Square
  test for Independence between
  groups.

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Measures taken

• Number of errors
• Task time
• Task completion

Effect discussed

• Icon effect
• Metaphor effect

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1) number of errors (in each task)
Statistical analyze using ANOVA

• In general, Subjects using the metaphor interface
  made fewer mistakes than subjects using the non
  metaphor interface.

The effects of metaphor and icon on number of
errors.

• The Icon did not make any significant effect.

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• The metaphor performances, on average were always
  better than the non metaphor.
• The effect of metaphor was uneven In some tasks
  the metaphor improved performance more than
  others.
• All subjects showed improvement over the blocks

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2) Task Time measure Statistical analyze
using ANOVA

• Shows similar pattern of result .

• subjects performed tasks faster in the metaphor
  experiments than in the no-metaphor experiments

• Again, subjects showed improvement over time

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3) task completion Statistical analyze using
Chi Square

• Chi Square analyses were performed on each of the
  factors the metaphor, the task and the block.
• Task completion was measure as binary value,
  1success, and 0failure.
• The results of the analysis show that the effects
  of metaphor on task completion also depended on
  the particular task.

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a) Icons Effect

• The use of icons didnt improve
  performance in any of the dependent
  measures.
• This suggests that the inclusion of icons does
  not appear to have neither negative effect nor
  positive effect.
• Future research needs to be performed to better
  understand this lack of icon effect.

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b) Metaphor effect

• All three dependent measures showed a similar
  pattern of results, suggesting that the use of a
  metaphor provides a large advantage in initial
  performance.
• it appears that the effect of the metaphor is
  provided through the terminology and not at all
  through the graphics.

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Metaphor effect unequal effect

• Because each task is different, the effect of the
  metaphor on some tasks is greater than on other.
• Here is an example of great effect
• The task Make it easy to get back to
  this place in the book/document later
• Requirement from the metaphor subject
• Click on the icon which was labeled
  bookmark.
• Requirement from the non-metaphor subject
• Click on the icon which was labeled
  hotlist.

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• Task Results
• Subjects took significantly less time to complete
  the task.
• Subjects made fewer errors on the task.
• There was a greater number of subjects who
  successfully completed the task.

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Preference Measures

• Subjects completed a post-session questionnaire
  in which they answered questions about their
  preference for the experiment in which they
  participated.
• Subjects were asked to rate the ease of use of
  the interface from 1 to 5.
• ANOVA were conducted on the answers to each
  question.
• When asked how easy to use their interface was,
  subjects using a metaphoric interface gave a
  higher score than those with a non-metaphoric
  interface (2.03 vs. 3.03)

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Subject rate of ease

• Subjects were shown a picture of each of the four
  experimental experiments and were asked to rank
  order the four experiments from the easiest to
  participate in to the hardest.
• An analysis of the results reveal that most
  frequent order was
• 1(easiest) - metaphor with icon
• 2 - metaphor without icon
• 3 - without metaphor with icon
• 4 (hardest) - without metaphor without icon.

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Preference Measures results

• The preference measures demonstrate a pattern of
  results consistent with the performance data,
  from the analysis we know that
• Subjects perceived the metaphoric interface as
  significantly easier to use than the non
  metaphoric interface.
• Subjects did not perceive a difference of
  difficulty or ease due to the use of icons.
• As hoped for the results were consistent.

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EXPERIMENT 2COMPOSITE METAPHORES
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Introduction

• The experiment investigates the characteristics
  that contribute to the effectiveness of a UI
  metaphor - specifically the integrality of the
  metaphor.
• A composite metaphor is a combination of
  metaphors that are not necessarily related to
  each other but together represent the structure
  of the system.
• Composite metaphors are common in user interfaces
  and frequently advocated by user interface
  designers.

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Example of composite metaphor We Want To Learn
About Computer System
A Computer System has the following components
We use A Collective Of Objects Which Create A
Composite Metaphor Which Used To Learn About The
Computer System
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Single metaphor Vs. Composite metaphor

• Sometimes, mismatched or incomplete
  correspondence between the source and the target
  domains in a metaphor comparison is addressed by
  composite metaphors.  

Example abacus is like Computer they both
make calculation, we used integral metaphor, but
the metaphor is incomplete
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We now create a composite metaphor to complete
the metaphor
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The effect of mismatches between base and target
domain

• Composite metaphor may help to minimize the
  amount of mismatches between the base (metaphor)
  and target domain. But are mismatches so bad ?
• Perhaps, it is better to preserve the overall
  structure of the target domain by designing the
  interface around a single metaphor (integral) ,
  rather than a composite.
• If the overall structure is important it is
  better to use Integral metaphor, despite the
  mismatches between the two domains. Because the
  result should be better.

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Different approaches taken by researcher about
what kind of metaphor to use

• There appears to be some controversy amongst
  researchers and user interface designers as to
  whether it is better to use an integral metaphor
  or a composite metaphor

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• 1. Some researches suggest composite metaphors
  can be useful, by helping the learner generate
  more and different kinds of conclusions about the
  nature of the target domain.

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• 2. Others argue that analogical mappings from
  multiple source domains can help people more
  efficiently create a single description in which
  the metaphor mappings are integrated and
  abstracted into a more direct representation of
  the target domain.

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• 3. Others claim it is better to use many
  different conceptual models, each one simple,
  each making a different point than one overall
  model which does not fit perfectly.

Example many simple model to one target
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• 4. In contrast to the others, some argue that it
  is better to design the UI metaphor around a
  single integral structure, relying on the
  systematicity principle, which states that
• A predicate that belongs to a mappable system
  of mutually interconnection relationship is more
  likely to be imported into the target

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Lets see a mappable system of mutually
interconnection relationship
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This experiment attempts to establish

• whether an integral metaphor is superior to a
  composite metaphor in terms of users
  performance.
• which type of metaphor is most effective in UI
  design
• who's right in the controversy review ?
• Whether or not it matters that those theories are
  drawn from areas such as education ?
• This experiment could provide a clear direction
  for UI design beyond the current generalization
  that metaphors are beneficial.

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Pilot Study

• A pilot study was conducted to enable
  development of a composite metaphor
  based on experimental data, which
  will be used in our
  experiment.
• The need An alternative metaphor, which will
  be combined with the library metaphor to create a
  composite metaphor. The chosen
  alternative travel metaphor
  Reason searching the web is analogical to
  traveling from place to place.
• Performance measures on the library and travel
  metaphors were used to select the tasks to be
  combined in the composite metaphor.  

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The pilot study propose

• The primary propose of the pilot study was to
  develop a composite metaphor which will replicate
  the performance advantage shown by the library
  metaphor.
• For some task it seems more natural to use travel
  metaphor, than library. Thus by combining the two
  metaphors, we expect that the composite will
  improve the performance of the integral metaphor.
• For example, it seems more natural to think about
  a photo album than a translator to a save as
  function.

Travel function
Original Mosaic function
library function
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The result of the pilot test

• The result of the pilot test shows us that
  not all metaphors are beneficial the
  travel metaphor did not show a performance
  advantage compared to its non metaphoric control.
  

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Subjects

• Thirty New Mexico State University students
  participated.
• They were compensated either by receiving 5.00
  payment or partial fulfillment of an experimental
  credit requirement in introductory psychology
• The same characteristics as in first experiment
  were used as criteria for participation.

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Materials and Procedure

• The same experimental paradigm as was
  used in Experiment 1 was used in this
  experiment.
• Subjects were randomly assigned to one of the
  three experiments
• Integral library metaphor.
• Integral travel metaphor.
• Composite metaphor (mix of library and travel).
• Interface elements in the composite metaphor
• Half were identical to the interface elements in
  the integral library metaphor.
• Half were identical to the interface elements in
  the integral travel metaphor.

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Function labels for each experimental experiment.
Notes the terminology for the 2 composite
functions labeled counter-balanced depends on
the task. For example in travel metaphor task the
counter-balanced functions will be Go
Forward and Backward
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integral library metaphor experiment
integral travel metaphor experiment
composite metaphor experiment
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EXPERIMENT 2 RESULT AND DISCUSSION
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Performance Measures

• In total, each subject completed 3 blocks of 10
  tasks in one of three experiments
• Integral library metaphor.
• Integral travel metaphor.
• Composite of library and travel.
• The measures taken
• Task time - average time to complete a task.
• Average number of errors.
• 3) Average rate of successful task completion.

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• The analyses on each measure were broken into two
  sub- analyses, which compared between
• 5 tasks that used the the library interface
  elements in the composite experiment VS
  the corresponding tasks in the integral library
  experiment.
• 5 tasks that used the the travel interface
  elements in the composite experiment VS
  the corresponding tasks in the integral
  travel experiment.
• The reason enable identical tasks to be
  compared to each other under two experiments.

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1) Task Time Measure
The effect of metaphor on mean task time for
library tasks and travel tasks.
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1) a. Task Time on the 5 tasks using the
library metaphor, Statistic analysis using ANOVA.

• Average task time was significantly longer for
  the composite library tasks and the integral
  travel metaphor than the same tasks performed in
  the integral library experiment.
• The mean task time

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Observations for the results

• These findings show that the overall context of
  the UI metaphor matters.
• Integral metaphors are easier to use than
  the composite metaphor.
• Although the same task is given to both the
  integral library metaphor and composite metaphor,
  and should be preformed in exactly the same way,
  the composite was worse than the integral.

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1. b) task time on the 5 tasks using the
travel metaphor Statistic analysis using ANOVA

• Average task time comparing travel metaphor and
  composite metaphor didnt reveal significant
  difference.
• Again comparing the travel and composite metaphor
  to the library metaphor shows significant
  difference.
• The mean task time

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Observations for the results

• There are some composite metaphors that
  are better than some integral metaphors.
• The poor performance shown by the composite
  metaphor may have happened because
  the composite metaphor diluted the positive
  effect of the good metaphor (library metaphor).
• If the metaphor is weak (travel metaphor) then it
  doesnt matter whether we mix it with another
  metaphor (composite), or not (integral).

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Task Time Dependent Measure Conclusions

• These results suggest that
• when the metaphor is good (Library metaphor)
  integral metaphors are better than composite
  metaphors.
• when the metaphor is bad (Travel metaphor)
  it does not matter whether we use the
  integral or the composite.

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• Possible explanations for this finding
• mixing the metaphor in the composite
  experiment, resulted in the dilution of
  the metaphor.
• the mix with the good metaphor resulted in bad
  composite metaphor.
• the mix with bad metaphor resulted in minimizing
  the poor performance of the poor metaphor

• the performance on the integral
  travel metaphor had reached the
  boundary (floor effect) and could
  get no worse.

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2) Error Dependent Measure3) Task Completion

• ANOVA was performed on the average number of
  errors.
• Chi-Square analyses performed on the number of
  task completion
• Both revealed a similar pattern of results to the
  task time measure.
• The chi-square analysis showed a significantly
  lower rate of task completion of the library
  tasks in the composite metaphor experiment
  compared to the same tasks in the library
  metaphor experiment.

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Preference Measures

• Subjects also completed a similar
  post-session questionnaire as was administered in
  the previous experiment.
• ANOVA were conducted on the answer of each
  question, which asked about the ease of use.
• On average, subjects rated the library metaphor
  as easiest to use and most helpful.

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Preference Measures Summary

• These results are consistent with the findings of
  the performance data.
• This shows that people prefer good integral
  metaphor over composite or poor metaphor.
• The subjects result showed that for a good
  metaphor, it is better to use an integral
  metaphor than a composite metaphor.
• However, in choosing a composite metaphor it may
  be beneficial to select various metaphors that
  are related in some way.

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CONCLUSION
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The results

• The results of these experiments support the
  belief that UI metaphors can facilitate the use
  of software.
• Not all metaphors are good.
• the metaphor advantage appears to be carried in
  the terminology and not in the icons (graphics).
• It is not known if these results generalize to
  the latest variation on graphical user interfaces.

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What next ?

• The next question is what are the characteristics
  of a good metaphor.
• Experiment 2 shows that the integral metaphor is
  superior to the composite, yet it didnt answer
  what makes a good metaphor.
• Further research is needed to address these
  issues of what are the fundamental qualities or
  characteristics of a good metaphor.

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Guidelines How to design user interface

• Designing an interface around a metaphor can
  provide substantial benefits in the users use of
  the software.
• The function labels (terminology) carry much of
  the weight in conveying the interface metaphor to
  the user, and therefore should be carefully
  chosen.
• When possible, use an integral metaphor rather
  than a composite metaphor.
• Note Icons while visually appealing, dont
  appear to effectively convey the metaphor.

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