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CS 5100 Foundations of AI

Assignment 4:
Creating a Sandwich Ordering System
Value: 10%


In this assignment, you will design and develop a sandwich ordering system. The system you develop will
take in a typed customer request for a sandwich, engage in a dialog with the customer to clarify details,
and then print out the complete order. For simplicity we will ignore details about cost. The system does
not really have to make the sandwich either!

The goal in this assignment is to get some idea of the logic used and issues involved in understanding
language in a dialog system that does something useful.

Chatbots are becoming common in such situations. See for instance
https://www.business2community.com/marketing-automation/want-to-boost-sales-heres-how-you-
can-with-chatbots-02119068 or https://www.qsrmagazine.com/technology/chatbots-are-changing-
how-customers-order, which give some examples of similar use-cases. However, our emphasis is not on
the highly polished natural language interface you see with a chatbot. Instead, our goal is to have you
concentrate on the logic behind such systems, finding out what information is available in the
customer’s order and what is not, and ensuring you get all the required information from the customer
by asking specific questions. In theory, using the information you put together in this assignment, you
could create a fine chatbot.

You can implement the coding part of this exercise using either Python or SWI-Prolog, as detailed
in Step 3.

Follow the steps below in doing this assignment.

Step 1: Decide on the sandwiches and options

In this step, you will decide what sandwiches and options you offer via your sandwich ordering system.
Customers can only order the sandwiches you offer, and they cannot create a completely new sandwich
from scratch. However, customers have a choice of breads, spreads, options and exceptions (see
examples below), and they can ask for any of these choices with any sandwich they order.

a. Your menu must at least 4 types of sandwiches, one of which has your name in it, such as
“Kim’s Veggie Special”. Decide what ingredients go into each sandwich. Use this information to
make up a description for each sandwich you offer. For example, you may describe “Kim’s
Veggie Special”, as “Swiss Cheese and avocado, with mayo, tomato, lettuce, onion, carrot, and
cucumber”

b. The menu must offer at least 3 options for each choice of bread, spread etc.

https://www.flickr.com/photos/littledebbie11/4055260418/

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c. For inspiration, see something like the Jimmy John’s or Subway pages at
https://resources.jimmyjohns.com/downloadable-files/Jimmy-Johns-Menu-2019.pdf or
https://www.subway.com/en-us/menunutrition/menu/all. These pages will give you some
ideas. Get creative, but don’t make things too complicated !

d. Decide on what you offer, including:

• What kinds of sandwiches you offer (e.g. Veggie Delight, BLT, etc.)
• What the usual ingredients of each sandwich are (e.g. bacon, lettuce and tomato for a BLT)
• What kinds of bread options are available (e.g. rye, wheat, etc.)
• What kind of spread options are available (e.g. butter, mayonnaise (mayo), etc.)
• What options are possible (e.g. toasted or not, “extra cheese”, “salt and pepper”, etc.) and
• What exceptions are possible (“no onions”, “hold the mayo”, etc.)

e. Create a file named README.txt . In that file, create a section titled “Step 1”. In this section,
list the sandwich choices available (including the one named after you) with the description of
each, and the breads, spreads, options, and exceptions offered. For each sandwich, make sure
you list the default value for each of the options such as bread, spread etc. offered.

Step 2: Decide on the logic of the system

In this step, you interact with the customer to get complete details of the sandwich they want. From
each initial customer request, you have to figure out what’s specified. If some details are not specified
by the customer, you should tell the customer what detail you’re looking for, what the options are, and
what the default is. You should then ask the customer to specify the details you require.

It is as if you use the customer input to fill out a form (or data structure) with the following details:

Name of sandwich:
Usual ingredients:
Bread-type:
Spreads:
Options:
Exceptions:

Of these, the name , bread type, and spread are required to be specified by the customer. Options and
exceptions are optional information: they may be specified by customers, but do not have to be. The
usual ingredients are known to the program from the name of the sandwich.

Here’s what we expect your program to do:

a. Have your program greet the customer and ask them what they want to have.

b. If the customer asks for the menu with a request like “What are the choices?”, “What’s on the
menu?” etc., display a menu with the sandwich choices and a description of each. Ask them what
they want to have.

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c. The customer should come up with an (initial) request that looks something similar to one of these
(these are only some examples; you can think of so many variations of these):
• Kim’s Veggie please with no onions.
• I want the BLT, Italian bread, with cheese.
• I’d like the Meat Lover’s on rye please, mustard, hold the mayo

Remember that customers can only order the sandwiches you offer, but they have a choice of
breads, spreads, options and exceptions, and they can ask for any of these choices with any
sandwich they order.

d. For example, if a customer just asks for “Kim’s Veggie on whole wheat please with no onions”, you
can imagine a form or data structure with the following details filled-in:
Name of sandwich: Kim’s Veggie Special
Usual ingredients: Swiss cheese and avocado, tomato, lettuce, onion, carrot, and cucumber
Bread-type: Whole wheat
Spreads: mayo
Options:
Exceptions: Onions

In this case, the customer has completely specified what they want. No other details are required.

e. But if some details are not specified in the customer’s initial request, you have to get them to clarify
their choice for each detail that is required. For example, if the customer does not specify any
particular bread for a sandwich, you may say “This sandwich usually comes with Italian bread. Press
return to accept this choice of bread, or choose one of the other alternatives: 1. wheat bread, 2. rye
bread.” Take the customer’s input and fill in the details provided. Decide also how you will respond
if the customer specifies irrelevant options, for example, asking for “No carrots please” even when
the sandwich they order does not have any carrots.

Note:
1. There is no requirement for any fancy UI. I’m expecting you’ll use simple print and read
commands (or the equivalent in Prolog) to interact with the user. Keep it simple!
2. You must have a list of terms that you treat as equivalent. Customers may say veg,
veggie or vegetarian (or mayo or mayonnaise) and you must treat each element in a set
of these terms the same as the other elements in the set.
3. Customers (the polite ones at least!) may use words/phrases such as “Please”, “I’d like”,
“Thanks”, etc., which you must learn to ignore.
4. Phrases like “Hold the onions” or “Hold the mayo” mean “I do not want onions” and
“I do not want mayo”, and you must add any such item(s) to the exceptions list.

f. After all the steps above, you will have complete details for the sandwich the customer is
requesting. Show the details that you have obtained, and get the customer to confirm that all
choices are correctly understood.

g. In file README.txt, create another section, and title it “Step 2”. In that section, provide:
• The list of terms you treat as equivalent
• The list of terms like “Please” etc. that you will ignore.
• The different ways you will allow customers to specify exceptions like “Hold the mayo”.
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Step 3: Coding and testing the system

Once you have decided what your menu options will be, and you have decided on the logic of the
system, you are ready to implement the system in this step.

a. You system should do the following, for each run of the system:

i. If requested, show a menu with the names and types of sandwiches available.
ii. Ask the customer what they want.
iii. Take input from the customer.
iv. Check to see if any details are missing, and if so, for each detail that’s missing,
get the required details from the customer as detailed in Step 2e above.
v. Once you have all the details required, and confirmed with the customer, print
out the details in the format shown in Step 2d above.

b. You can implement this system in Python or SWI-Prolog. Do not use any chatbot package or a
bot framework. You can use any regex package to identify relevant words in the customer’s
input. Make sure you implement what we have defined above, but keep it simple. Name the
main program sandwich (i.e. sandwich.py or sandwich.pl, as appropriate).

c. Do not use any natural language library such as nltk or spaCy – these packages are way more
complex than what is required for this assignment.

d. Important: If you are thinking of using any other package that you think will be useful, check
with us on Piazza before using these packages.

e. In file README.txt, create another section, and title it “Step 3”. In that section, tell us the
programming language you used to implement the system, and list the commands required to
run the system. Also list the files that you wrote to implement this assignment, and write a one-
line description of the contents of each file.

Step 4: Demonstrating the system

In this step, you demonstrate what your program can do, and how it does what it does.
a. In file README.txt, create another section, and title it “Step 4”.

b. Identify 3 examples where the sandwich ordering system takes customer input, and creates
something for the customer based on incomplete specifications for the sandwich. At least 2 of
these examples should be incomplete specifications requiring the system to check with the
customer to get additional details. Run these examples on your system, and cut and paste the
whole interaction for these examples in section Step 4 of README.txt, under subsections titled
Example 1, Example 2, and Example 3.

c. Identify a 4th example where the sandwich ordering system takes customer input, and fails to
create an order for the customer, because the logic of the system does not support something
the customer is requesting. Run this example on your system, and cut and paste the whole
interaction for this example in section Step 4 of README.txt, under a subsection titled Example
4. Explain in 1 or 2 sentences why the system fails in this example.
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Step 5: Submitting the assignment

In file README.txt, create another section, and title it “Step 5”. In this section:

a. Write 1-2 sentences about what the easiest part of the assignment was.

b. Add another 1-2 sentences about the hardest part of the assignment.

c. Finally, add 1-2 sentences about what you learned from doing this assignment.

d. When you have all your files ready, zip up the files into one .zip file named
yourFirstName_yourLastName_Assign4.zip and submit the zip file via Blackboard.

Hope this assignment is a fun and learning experience for you! We will try out a few assignment
submissions in class – remember, your program could be the one selected !