IAT 334 - D102
HEURISTICS ASSIGNMENT:
SUPERSTORE SELF-CHECKOUT
Brendan Lane
Christie Wong
Levona Yim
Patrick Magdua
RESEARCH CONTEXT
WHY SUPERSTORE SELF-CHECKOUT?
Our group chose to evaluate a self-checkout system at a grocery store, an interface with which we are all familiar
but with which we do not interact regularly. To achieve standardized results across all group members, we
specifically chose Superstore, and decided that our goal would be to purchase a produce item from Superstore
utilizing the self-checkout system. We chose this specific task because the purchasing of a produce item
requires more steps than a scanned item - for example, it requires finding the item in a catalogue and then
weighing the item - and thus would allow us to more thoroughly examine the interface’s usability.
NIELSEN HEURISTICS
WHICH HEURISTICS TO CHOOSE?
1 Visibility of system status
Let shoppers know how far along they are and how close they are to finishing
2 Match between system and real world
Grocery shoppers aren’t technical users - ensure they can easily understand the system
3 Recognition rather than recall
Don’t make shoppers remember what they bought, show them what they need
4 Error prevention
Shopping involves money - don’t let users make mistakes with their cash!
5 User control and freedom
Let users navigate freely in the interface, give them the ability to undo/redo
6 Help users recognize, diagnose, recover from errors
If mistakes are made, ensure users can fix them. Again, shopping involves money
7 Consistency and standards
Ensure that the interface looks and behaves the same way across screens
LET’S GO SHOPPING!
EVALUATION TASK WALKTHROUGH
1 What the checkout stand looks like
2 Start screen
3 Press the start button
4 Confirm/deny PC Plus membership
5 Select produce button
6 Select item code or category
7 Select vegetable category
8 Select item
9 Weigh item
10 Place item in bag
11 Pay for order
12 Select number of bags
13 Receive cryptic message
14 Select payment method - cash
15 Pay for groceries
16 Wait for transaction
17 Remove bags from bagging area
18 Receive change
19 Receive receipt
HEURISTIC VIOLATIONS
HOW DID THIS CHECKOUT VIOLATE
NEILSEN’S HEURISTICS?
VISIBILITY OF SYSTEM STATUS
MEDIUM SEVERITY VIOLATION
When trying to find a specific item, there are a lot of steps (category, vegetable, quantity, weight)
and no sense of where we are in the process. We also don’t know where we are in the entire
grocery shopping process.
This isn’t a huge deal because the shopping process is fairly straightforward.
SOLUTION
Use a breadcrumb trail to show users where they’ve been and allow them to more easily navigate
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg 1.48 PRODUCE VEGETABLES
Please select your item from the list below.
Artichokes, Asparagus, Beans, Corn, Peas
Celery, Herbs
Broccoli, Cabbage, Fresh Peppers
Cauliflower, Cucumber
Garlic, Onions Lettuce, Leafy Greens
Mushrooms, Eggplant Squash, Zucchini
Potatoes, Yams
Ethnic Vegetables Organic Vegetables
Subtotal $1.48
Other Root Vegetables Item Not Displayed
Switch Adjust Call Cancel
Language Volume Attendant Order
Back
MATCH SYSTEM AND WORLD
MEDIUM SEVERITY VIOLATION
Fruits and vegetables are categorized in seemingly arbitrary ways, under headings such as
“miscellaneous fruit” which don’t correspond to common language.
This can make finding rarer produce items very difficult, as the navigational paths are not always
logical or straightforward.
SOLUTION
Use sensible headings, alphabetize fruit list, use real world terms
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Plum Black (4040)
0.315 kg NET @ $6.57/kg $2.07
Please select from the categories below.
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg $1.48 Apricots Avocados
Bananas Kiwi Fruit
Lemons Large Lime
Mangos Red Small Papayas
Subtotal $3.55
Switch Adjust Call Cancel
Language Volume Attendant Order
Back
RECOGNITION OVER RECALL
MEDIUM SEVERITY VIOLATION
The interface asks you to define quantity of an item, but removes references to the item so it’s
possible to forget what item you’re currently purchasing.
This can cause a user to type in the wrong quantity or try to go back to ensure that the item they’re
counting is the right one - this costs them time.
SOLUTION
Keep a reference of the item onscreen so the user remembers what item they’re purchasing
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg 1.48
Please type your quantity of Kale and
press “Next”
1 2 3
4 5 6
Subtotal $1.48
7 8 9
0 x
Switch Adjust Call Cancel
Language Volume Attendant Order
Back Next
ERROR PREVENTION
LOW SEVERITY VIOLATION
The starting screen asks users to press start, but the button asking them to use green bags or a
Greenbox has more hierarchy - this can cause users to press the wrong button.
However, users can always add or remove bags at a later time, so this has little severity.
SOLUTION
Ask for users to provide bags at a later time, restrict the start screen to language selection
SUPERSTORE CHECKOUT
WELCOME!
Please select your language to start.
English Français 中文
CASHLESS LANE
This lane accepts:
SUPERSTORE CHECKOUT
WELCOME!
If you have a Greenbox or green bags,
Please select
please place your language
them on toarea.
the bagging start.
English Français
Continue 中国的
CASHLESS LANE
This lane accepts:
USER CONTROL + FREEDOM
LOW SEVERITY VIOLATION
Some of the checkouts are cashless, meaning they don’t accept or dispense cash. They warn the
user about this, which helps prevent errors, but they only provide the user with this warning
message after several steps. This can cause users to waste time if they don’t have cash.
SOLUTION
Ask the user if they have cash right away
SUPERSTORE CHECKOUT
WELCOME!
This machine does not accept or
Please select your language
dispense any cash. to start.
Continue?
English Français 中国的
Yes No
CASHLESS LANE
This lane accepts:
USER CONTROL + FREEDOM
LOW SEVERITY VIOLATION
Keypads lack backspace buttons, meaning that every keypad error requires users to completely
clear the keypad rather than correct a small mistake. It is a minor frustration, but one that strips
control away from the user.
SOLUTION
Give users the option to correct errors rather than clear the entire field
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg 1.48
Please enter the number of bags you
wish to purchase and press “Next”
1 2 3
4 5 6
7 8 9
Subtotal $1.48 No bags 0 x
Switch Adjust Call Cancel
Language Volume Attendant Order
Back Next
USER CONTROL + FREEDOM
HIGH SEVERITY VIOLATION
Occasional lack of a back button to allow users to go back a step. This is especially baffling
considering that the button exists in some screens but is completely absent in others. This can
cause major frustration and confusion if the user needs to go back a step.
SOLUTION
Have a consistent and visible back button at every step
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg $1.48
Please scan your next item or select an option below.
$1.48 Large/Long Items Produce/Bakery/Other Items
Subtotal
Redeem Coupons Reduced Price Items
Pay For My Order
Switch Adjust Call Cancel
Language Volume Attendant Order
Back
USER CONTROL + FREEDOM
MEDIUM SEVERITY VIOLATION
There are a lack of language options - in Richmond, why do only English and French exist when
there is a large Chinese-speaking population?
The system caters to Canada’s national languages rather than the languages that the users would
actually speak. People who have trouble speaking English lose control due to language problems.
SOLUTION
Offer logical language options given the cultural context of the store
SUPERSTORE CHECKOUT
WELCOME!
Please select your language to start.
English Français 中文
CASHLESS LANE
This lane accepts:
ERROR RECOVERY
HIGH SEVERITY VIOLATION
In multiple cases, we had error messages arise that don’t tell users what’s wrong. They simply ask
for the user to wait for an attendant, or ask them to wait with the option of calling an attendant,
but the messages confuse users by not helping them recognize errors.
SOLUTION
Have error message clearly explain the problem, and provide them with logical options
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg 1.48
Please enter the number of bags you
Please wait... wish to purchase and press “Next”
The system needs a moment to
process your order.
Call an attendant if this process is1taking 2 3
too long or if you have a question.
4 5 6
Call
Attendant 7 8 9
Subtotal: $1.48 No bags 0 x
Switch Adjust Call Cancel
Language Volume Attendant Order
Back Next
ERROR RECOVERY
HIGH SEVERITY VIOLATION
We found that if we there was no easy or visible way to remove an item from our shopping cart if
we no longer wanted it. We had to call an attendant if this problem arose, defeating the purpose of
the self-checkout, taking control away from the user, and preventing them from correcting their
mistake on their own.
SOLUTION
Give users a series of options when then tap on an item, including the option to remove the item
from the shopping cart
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Plum Black (4040)
0.315 kg NET @ $6.57/kg $2.07
Please Scan,Select a category, or Enter
in the 4-digit code of your next Item
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg $1.48
You’ve Selected...
1 2 3
Plum Black (4040)
4 5 6
0.315 kg NET @ $6.57/kg $2.07
$2.07
7 8 9
Call
Delete Continue
Attendant
Done 0 x
Fruits/Nuts Vegetables
Subtotal: $3.55 Pay Order
Produce Large/Long
Bakery/Other Items
Switch Adjust Call Cancel
Language Volume Attendant Order
Back Next
ERROR RECOVERY
MEDIUM SEVERITY VIOLATION
Users can’t proceed to the purchasing stage if they have items on the scanning area. Once this
error is committed, there is very little feedback given to users to tell them what to do. This can lead
to frustration and unnecessary confusion at the end of the shopping process.
SOLUTION
Give users a clear error message telling them what is wrong and how they can rectify the situation
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg $1.48
Please scan your next item or select an option below.
Cannot proceed to payment!
Please remove items from scanning
area and place them in bagging area,
then press continue.
Continue
$1.48 Large/Long Items Produce/Bakery/Other Items
Subtotal
Redeem Coupons Reduced Price Items
Pay For My Order
Switch Adjust Call Cancel
Language Volume Attendant Order
Back
CONSISTENCY AND STANDARDS
HIGH SEVERITY VIOLATION
The number of options on the bottom left-hand corner changes from step to step. Furthermore,
some options are switched out with others with no warning. This leads to an inconsistent set of
options that cannot always be accessed - most notably, many screens lack the ability to go back a
step or cancel an order.
SOLUTION
Provide users with a consistent set of options which they can make use of, and instead of removing
and switching out items, grey out the ones that cannot be used at that time
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg $1.48
Please scan your next item or select an option below.
$1.48 Large/Long Items Produce/Bakery/Other Items
Subtotal
Redeem Coupons Reduced Price Items
Pay For My Order
Switch Adjust Call Cancel
Language Volume Attendant Order
Back
SUPERSTORE CHECKOUT
1. Scan Items 2. Payment 3. Done
Zucchini Green (4067)
0.690 kg NET @ $2.14/kg $1.48
Please place items in the bag.
$1.48 Large/Long Items Produce/Bakery/Other Items
Subtotal
Redeem Coupons Reduced Price Items
Pay For My Order
Switch Adjust Call Cancel
Language Volume Attendant Order
Back
THANK YOU!
