Beverage Vending Machine Comparisons

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Beverage Vending Machine Comparisons Powered By Docstoc
					Evaluation Project                                             Interactive Media ‘04

                              Beverage Vending Machine
                                     Evaluation Project
                     Maébh Costello, Celeste Bergin, Michelle Noonan

    The coffee vending machine chosen for evaluation for this project was
determined to be a good example of a product that was designed for functionality
only. Due to innovations in design areas, more innovative features must reinforce
functionality. It was these aspects of modern interaction design that were applied in
the evaluation of this project.

                                     Project Research
    Before actually evaluating the project it was decided to look into how similar type
machines were designed. The study group visited several food/beverage
establishments, taxi companies, and shopping areas to make comparisons to similar
products. Photographs were taken of other vending machines to assist in the
evaluation process. The next step was to search companies with similar products on
the Internet, which was successful in terms of comparing similar usage types of
machines and selection design.
    By looking at a variety of vending machines a list of user-friendly features was
developed. These features include:
       Large LCD screen with good contrast between text and background
       Adequate button size for user‟s fingers to make selection
       User‟s preference choices near the basic selection
       Visual categorization through use of colour
       Readability of text
       Pictorial representation of product selection
       Organization of information that is simple and clear to follow
       Graphical symbols to give direction of steps
       Height level of dispenser near user‟s waist that provides easy access
       Coin return does not require bending or stooping
       Minimal written directions
       Good drip system for dispenser area for spillage

Evaluation Project                                             Interactive Media ‘04

                                     Targeted Users
    The main users targeted for this study were guests to the college, students, staff,
and faculty since they are the ones most likely to use the machine to obtain a
beverage. For ergonomic and anthropometric reasons we chose a specific range of
users to complete our task analysis. A selection of users was based on height,
gender, culture, and job or role (i.e. students, office support, security, and English

                                Initial User Observations
    Initial observations were made of the users interacting with the machine‟s
interface. This allowed the group to view the natural use of the machine (user
oblivious to observation). Detailed notes were compiled using this method to pinpoint
design issues in terms of users‟ interaction with the machine interface. This process
allowed the group to identify critical stages of interaction of the machine and define
requirements for a user task list.

                                      Task Analysis
    In order for the user to receive a beverage from the vending machine he or she
must complete a series of simple tasks. They must do the following steps in order to
do so:
         1.     Be able to find information if needed to operate machine
         2.     Insert coins
         3.     Adjust the strength of the beverage
         4.     Select sugar if desired
         5.     Press the desired selection
         6.     Remove change if necessary
         7.     Remove beverage from dispenser

    Users were given has much time as needed to complete these tasks. This is to
determine the usability of using the beverage vending machine without outside
assistance. It is assumed that all the instructions that they will need will be available
through the vending machine interface. These seem like simple steps but will the
design of the machine support the ease of these straightforward tasks?

Evaluation Project                                            Interactive Media ‘04

                               User Interaction Process
    Initially users approached the unit and examined the menu possibilities. The
menu system on this machine model has not proven to be user-friendly as indicated
by users who “think aloud.” For example, the user would search the menu to
determine which step to do first – insert money, make selections, or make extra
preference selections. It was also noted that users who “think aloud” made the
comment that they were not sure when the dispensing was finished and had to
“queue” to get the beverage. Difficulties with these aspects of the vending machine
add an air of confusion. This is due to a several issues:

    1. Cluttered menu layout
    2. Badly displayed instructions
    3. Repetitive logo illustration
    4. Visual mapping disorientation
    5. Product feedback
    6. Lack of visual consistency
    7. Menu selection constraints

    Users acknowledged via surveys that they viewed the machine as an
uncomplicated product. However, usability studies, video footage and photographic
references show and outline the product usability as poor.

                            Results of User Questionnaire

       80% of users visually navigated the machine interface by mapping, affordance
        and memory.
       Average user interaction time was 52 seconds.
       The most confusing aspects of the menu interface were found to be: Selection
        Method, Sugar and Extra Sugar, Strength.
       The machine LDC screen was found to be „Useful‟ by 70% of users.
       Half of all users were unaware of the pricing of each beverage.
       All users reported the company logo easier to read that the actual selection
        menu and prices.
       All users said they would like a pay by notes and coin system.
       90% of users were unaware when their beverage was ready for removal.
       Only 10% users noted the beep noise that indicated that the beverage was
        ready for removal.

Evaluation Project                                             Interactive Media ‘04

       A large majority of users (80%) were unhappy with the cup dispensed with the
       70% of users reported that the hygiene of the machine would affect their
        purchase of a beverage.
       All surveyed stated that they could not view what was occurring in the drip
        tray area of the machine, from a standing position.
       All users reported that they were unhappy with the after sale service of their
    Surveyed users reported the product to be average in terms of usability. Even
though 80% of users visually navigated the machine interface by mapping,
affordance and memory, the average user interaction time with the machine is 52
seconds. Evidence indicated that even though users are previously aware of
product, usage time is not very inefficient.

                               Video Analysis of Users
    For the most part users of the beverage vending machine were able to walk away
with something to drink from the machine as indicated from the video footage. The
time it took to actually take the drink depended on their knowledge of how the
machine worked, their ability to find the information to make their selection, the type
of drink selected, and in one case the ability to understand the written language of
    Analyses of the video footage indicate a number of common difficulties with using
the beverage vending machine. The observed difficulties among users are:

       Ability to locate directions with ease and/or navigate visually without reading
       When to make a pre-selection, i.e. extra sugar or strength
       Feedback from the machine when it recognizes that a selection has been
        made by the user
       Necessity of bending down or stooping to see if beverage has been
       Necessity of bending down or stooping to collect change or drink
       Careful removal of cup from dispenser due to a flimsy container
       Necessity of holding cup near the top due to heat
       Length of time for product to dispense
       Occasional malfunction of machine with no number available for assistance
       Cleanliness of dispensing area was an issue

Evaluation Project                                            Interactive Media ‘04

These key points of issue with the beverage vending machine are features that can
be addressed through designing an easier user interface that can be more attractive
and interactive.

                            Functions and Feature Analysis
    The most confusing aspects of the menu interface were found to be with the
selection method, sugar and extra sugar, and strength.

        1) Selection Method
        The drink selection process was confusing to novice users. The user must
        first add strength and sugar to the beverage before selecting a drink option as
        reflected in the instructions below. This aspect of the menu confused users as
        they were initially selecting a beverage first, consequently missing the
        opportunity to adjust their beverage to taste.
                Step 1. Insert coins
                Step 2. Adjust strength if required
                Step 3. Select sugar if required
                Step 4. Press desired drink selection
        This occurrence is mainly due to badly displayed instructions and poor menu
        interface options.
        2) Sugar and Extra Sugar
        The add sugar and add extra sugar options were overlooked by many users.
        Users reported this to be due to a badly menu arrangement and display.
        3) Strength
This feature was designed to allow the user to adjust their beverage selection to their
personal taste by strengthening the beverage of choice. 60% of users did not utilise
this function, as they did not know what it was.

Screen Display
    A large majority of users surveyed revealed that they found the LCD display
screen helpful. But when quizzed about the feature in more detail, a range of
difficulties were found:
       A larger is screen required
       Needs to be placed at an average eye level
       Larger visible screen text

Evaluation Project                                            Interactive Media ‘04

More detailed instructions, via the display screen, are needed to guide the user
through the process.

Menu Selection Buttons
    Adult male and female anthropometrics figures do not comply with the size of the
button features on the menu. The button measurements are far too small for user-
friendly usage. The buttons in this machine were also doubled functionally as they
hosted the price details of the beverage it represented. On the menu consol area the
button features were over-shadowed considerably by company logo displays

Price List
    The price list for the menu selection is positioned on the actual selection buttons,
as stated above. This listing system proved to hinder and confuse the users, as half
were unaware of pricing while using the machine. All of them in the user test had to
lean towards the machine and squint to read the price details.

    It was determined that visual consistency in the text and graphic layout was
poorly designed. In terms of consumer graphic navigation, this machine rated very
low. The company logo is featured 18 times on this machine, taking up a large
proportion of the products visible surface. It proved to be a confusing element with all
users tested in the usability study. All of users reported the company logo easier to
read than the actual selection menu and prices. It is needless to say that this type of
design concept is very mediocre and hindering in the usage of the interface.

                                   Payment Method
Coin Slot
    The coin slot on the machine is not explained or even sign posted. Nevertheless,
users‟ familiarity and memory of this payment method meant that no issues were
founded here.

Additional Feature
    The spare change factor of the vending machine proved to be an issue with a
large proportion of or users. All of users said that a note payment method should be
incorporated into the machine.

Evaluation Project                                           Interactive Media ‘04

Change Button
    The change button was not utilised by any of the testers. When quizzed about
this feature the users reported the feature as an unnecessary part in the product
design. Due to the fact that the change is automatically dispensed as soon as an
option on the menu is selected.

Change Indicator
    The change indicator consists of an orange LED positioned to the left of the coin
slot. The instruction and explanation of this feature is placed directly below the coin
slot. The positioning in this case is acceptable, but the description details are very
badly displayed. The text is in a small font, coloured white on a grey background.
These factors combine to displayed bad instructions.

Coin Collection
    The coin collection point on this machine is positioned at the bottom right hand
corner. All of users were recorded bending down drastically to retrieve their change.
For ergonomic reasons small, average and tall men and women were chosen to take
part in the usability testing. This aspect proved that the coin collection point is
positioned at a very impractical vantage point

    The main instructions for the machine are placed to the lower left of the LCD
screen and consist of white text on a black background. The instructions themselves
are easily understandable. The instructions appear twice on the machine; however
users still found them hard to locate and use affectively.
    On the instructions situated beneath the LCD screen on the unit, the information
is presented in five different languages, English, Italian, French, German and
Spanish. This is a helpful element on the machine but this is the only place other
languages are used; every other text-based aspect is presented in the English
    Instructions for the payment method are also present. Yet these instructions only
go as far as to inform the user which coin denomination the machine accepts.

Evaluation Project                                                Interactive Media ‘04

                        Distribution Point and Drip Tray Area

Drip Tray
    All of those surveyed revealed that they could not see what was occurring in the
drip tray area of the vending machine. This factor proved to be substantial in the
evaluation of this product, as this is one of the fundamental actions of the process
involved in usability. Many complications were incurred due to this design flaw.

    When a beverage is vended it is released into a holder for the user to retrieve the
hot drink. However, due to poor visibility, users found that spillage occurs, as they
have to bend down to view what is happening in the drip tray area. All end products
from these vending machines are hot drinks; it is needless to say those spillages are
harmful to the user.

                                  Removal of Purchase
    The correct way to remove the drink from the dispenser is to squeeze the plastic
cup as you pull it outwards. These instructions are not displayed anywhere on the
unit. With this factor in addition to the poor visibility issue spillages are a given.
    Operation completed, 90% of users were unaware when the process was
complete and were unsure as to when to remove the drink. The machine does
indicate its completion by beeping in sequence however only 10% of our users
noticed this.
    Through the usability test it was noticed that when removing the cups from the
distribution area, users were holding them at the very top. This is due to the lack of
correct insulation in the plastic cups. 80% said that they would prefer a cup with a lid.
Styrofoam was the most popular cup material selection.

    This beverage vending machine is restricted to vending hot drinks only. Still basic
design flaws are present within the machine distribution of these hot items. Users‟
tests have highlighted the fact that 80% of users experienced spillages while
removing their selected item from the machine. This is due to 3 basic design errors:

        1) Distribution drip tray area placed too low down on the machine, disabling
           user to visualise what was occurring.

Evaluation Project                                              Interactive Media ‘04

        2) To remove a beverage from the machine the user must first squeeze the
           cup slightly to remove it from the distribution point. However this function is
           not explained anywhere on the machine. The cups utilised in this vending
           machine are light plastic. This cup is inadequate when dealing with hot
Although not life threatening, when dealing with hot substances certain standards
must be met.

    A high percentage of users (70%) described the drip tray area as dirty. 80% of
these report that an unhygienic and dirty machine would stop them from using it. Due
to the spillage factor (outlined above) the surrounding floor area of the machine was
dirty and grubby. The hygiene of the selection menu was also a factor. Due to the
faded and unclear condition of labels made the machine „look‟ unsavoury.

                                   After Sale Service
    No contact information appears on the machine in the case that a problem should
occur. Users have reported that this is a very irritating factor. Many users reported
that when a problem occurs, e.g. machine steals money, their frustration is taken out
on the machine. This frustration can take the form of screaming, cursing or even
physical contact (kicking the machine).
    This product is a good example of human feeling in relation to system/product
usage - e.g. one individual asked to take part in the study refused as they felt that
that particular machine „was out to get them‟. In the few times that the individual had
used the machine it did not vend the selected item or stole the money inserted into it.

    A number of ergonomic issues where identified with this vending machine.

        1) All the user spectrum participants had to bend down to retrieve selected
        2) This bending down aspect also occurred when retrieving change from the
        change collection point.
        3) All surveyed revealed that they could not visually see what was occurring in
        the distribution area of the machine.
        4) Cups were insufficient for the task of holding hot beverages as they did not
        protect the user from the heat element of their selected drink.

Evaluation Project                                             Interactive Media ‘04

         5) User confusion led individuals to leaning and squirming in indecision and
         puzzlement. This aspect can be easily viewed on the accompanying video
         footage for this paper. Users bent their spines in compromising ways.
         6) The insert coin facility also proved to be very un-ergonomic.

     The more experienced users that took part in the usability study completed tasks
from memory. Consumers are used to vending machines having very bad user
interfaces, so they are unaware of the negative issues surrounding this product. This
beverage vending machine complies with the standard layout of conventional
vending machines where the coin input slot and menu interface are positioned at the
top of the machine. The drip tray and coin collection slot are positioned at the bottom
of the unit. These facts also allow users to build a memory of usage when using the
product. Conventional designs, for example, ATM machines and toiletry machines,
allow this „pre-training‟. This affordance of previous knowledge use is a leading factor
in users‟ navigation skills on this particular vending machine.

     Upon completing the data analysis of the usability of the beverage vending
machine it was concluded that a reworking of the user interface and physical
characteristics would be effective to facilitate operation. Areas of improvement would
be in the organization of the information needed to complete the process and the
physical approximation of the dispenser and change return. Input from the users
indicated that they would prefer a different type of cup in terms of material due to
heat radiance and durability. All these ideals for the redesign process are
incorporated into the prototype proposal.

                                   Redesign Proposal
Menu System
     Push the technology of the product into the contemporary century. Use a large
touch screen menu to incorporate all menu possibilities:
        Menu selection
        User preferences, e.g. add sugar

Evaluation Project                                               Interactive Media ‘04

        Change return
        User instructions
        Operation process indications
        Effective advertisings
        Various options for text readability e.g. increased text size options
        Various language options (consistent to whole process)
        After sale service details
        Touch screen button must be large and concise.

Product Internal Architecture
     Rearrange the product architecture to allow for a complete product redesign from
the inside out. The research completed for this project depicts that the re-design of
these features are not restricted in any way. By redesigning the machine in this
method, it affords a more effective end product.

Target Users
     The machine must be designed with all users in mind.

         1) The external interface and interaction elements for the consumer users.
         2) The vending machine maintenance issue must be made user friendly for
         ease of preservation and upkeep.
         3) The issue of stocking up the machine with consumer products must be
         made effective and efficient.
     90% of individuals who are responsible for stocking revealed that the biggest
vending error factor is due to bad stocking and placement of products within the

Product Hygiene
     The hygiene factor proved to be a very important element to consumers. With this
in mind certain concepts must be kept in mind for the redesign. Minimal visible spilt
lines and joins on the front surface area. The less nooks and crannies there are for
germs and dirt to breathe in, the better. An effective drip tray design must be
incorporated into the design as a number of issues were found in this area.

Payment Method
     The advised payment method would take both coin and paper money. All of the
payment features should be positioned at an ergonomically comfortable level. No

Evaluation Project                                            Interactive Media ‘04

bending involved. The payment method instructions would be displayed on the touch
screen interaction menu.

Beverage Holders
     A more eco friendly cup material that has the ability to insulate the hot beverage
must be incorporated into the machine. A high percentage of users reveal that they
would like a lid to cover their beverage.

Beverage Distribution
     A new beverage distribution method must be integrated, one that does not hinder
the user and complies with safety standards.