2002 PhD. Core Exam: Part 1
MIS Dept, Univ. of Arizona, Tucson, AZ
Tuesday, May 28, 2002
Venue: Room 214, McClelland Hall
Time: 9:00 AM – 1:00 PM
INSTRUCTIONS: (Please read them carefully before you begin the exam)
1. The exam will begin promptly at 9:00 a.m. and end promptly at 1:00 p.m. No extensions are allowed.
2. This exam consists of 6 questions. You are required to answer all of them. Please allocate roughly
30 minutes per question and leave some time for checking your answers.
3. Each question is worth 100 points.
4. For each question, state your assumptions clearly.
5. If you are writing by hand in a blue book, please answer each question in a separate blue book. If
you are using a word processor, please make sure that you start each new question on a new page.
You are allowed to use combinations of the blue book and a word processor file for answering
questions.
6. At the top of each question that you answer, please identify two things:

The number of the question that you are answering and

The code name given to you at the beginning of the exam. Do not write your real name
anywhere on the exam, and use only your code name.
7. Please make two (2) diskette copies of the files containing your answers if you are using a word
processor. Please turn in both diskettes, along with your blue book answers and the exam questions,
to the proctor at the end of the exam.
8. You are allowed to take a restroom or lunch break only if no one else is already taking one. You
should get the proctor’s consent before taking a break, and also inform him as soon as you return
from your break.
9. If you are using a word processor, please make sure that you save your answers frequently. It is your
responsibility to ensure that you do not lose work.
10. The exam is CLOSED BOOK. Accessing the web on the computer is NOT allowed and will be
severely penalized.
11. Some questions have multiple parts. Make sure you answer all of them and number them properly.
12. You have been provided with MSWORD and POWERPOINT.
GOOD LUCK!!
1
Question 1: This question is about various ways to locally interconnect computers. (100 points)
A. (10 points) Consider a set of computers that are connected by communication channels that each
connect exactly two computers, and every computer is connected to every other computer. What kind
of network is this?
B. (10 points) Describe briefly an advantage of this kind of network vs. an Ethernet LAN which makes
use of a Hub or a Switch. Hint: think about security and privacy.
C. (10 points) For N computers, how many connections do you need? Every time you add a new
computer to this type of network, how many new connections do you need?
D. (15 points) Explain how LAN technologies, developed in the 1960s and 1970s, reduced the costs
from the type of network we are talking about in parts 1A through 1C. Explain what new kind of
competition this introduced among the computers and the issues this raises that LAN standards must
address.
E. (15 points) Describe collisions in a typical wired Ethernet LAN. What defines a collision? How can
they happen given that this LAN uses CSMA? What happens once a collision occurs? How does the
standard try to prevent subsequent collisions between the two computers that caused the original
collision? What happens if the same two computers collide again?
F. (15 points) Describe the key differences between your answer to IE and the situation with wireless
Ethernet LANs broadcasting at 900 MHz. Do the wireless Ethernet LANs use CD (Collision Detect)?
If not, how else can they manage collisions?
G. (5 points) What is the wavelength of the broadcast LAN described in Question 1F. Take the speed of
light to be 3 * 10^ 10 cm/sec. Make sure to write the units of your answer.
H. (10 points) Suppose you have N computers on an Ethernet LAN which uses a hub, and the probability
than any one of the computers might transmit in a given time interval is 0.05. What is the probability
that a collision will occur? You do not need to simplify your answer.
I.
(10 points) Now consider the case of having exactly 4 computers on this LAN. Solve the problem of
1H considering a Switch instead of a Hub with N = 4. The probability that any of them can transmit
is still 0.05. You do not need to simplify your answer.
Question 2: Networking Concepts (100 points)
A. (20 points) What is an Ethernet Repeater? What is the purpose of using it? What layer is this device?
If the original effective length of an Ethernet segment is 500 meters, what is the new effective length
after we use a repeater? Why can't we extend Ethernet segments indefinitely with repeaters? How
many can we use, maximum, between any two Ethernet stations?
B. (20 points) Describe the key similarities and differences between Bridges and Repeaters. At what
layer are Bridges? Do they have NIC cards? Do the hosts on the LAN “see” the Bridge or is it
invisible to them? Describe how the bridge does “frame filtering”. What kinds of frames does it not
pass between Segments? What is the startup behavior of a Filtering Bridge? (hint: at startup, all the
Forwarding Tables in the bridges are empty).
2
C. (10 points) Describe and define the acronym VPN. Describe a business or university scenario where
you would want to use it.
D. (20 points) Describe and define the acronym LDAP and Access Control Lists and how they come into
play when considering VPNs. What layer is the LDAP protocol at? How do programming languages
make use of LDAP? Describe the basics of the LDAP data structure.
E. (15 points) Distinguish between a Connection-Oriented and Connectionless paradigm. Which one
has an analogy to the USA postal system? Give 2 examples of a Connection-oriented Public
Switched Data Network (PSDN) and 1 example of a Connectionless PSDN.
F. (15 points) Why does the TCP/IP Protocol software design create a need for DNS? In other words,
why do we need DNS; how does the DNS protocol make day-to-day work easier for people? What
does the DNS acronym stand for? What layer is it at? What is the name of the special records DNS
uses in conjunction with e-mail? What special records alias one domain name to another?
Question 3: Trees for DBMS and data mining: (100 points)
A. Please define a B-tree of Order 2 and draw a B-tree example with sample records. Explain why Btrees are often used in relational DBMS. (30 points)
B. Please present the data structure and algorithm used in the ID3 inductive learning method. (30 points)
C. Please present a business problem that is suited for using ID3. Please explain the characteristics of
your problem and the steps (for your business problem) involved to perform your knowledge
discovery task. (40 points)
Question 4: Internet Search Engines: (100 points)
A. Please define “spamming” in Internet search engines. Describe one example of spamming and
suggest a way to detect it. (30 points)
B. Please present an architecture and its related technical components for creating a B2C (business to
customer) product storefront. Choose and describe your own product or service. (30 points)
C. Please describe the similarities and differences between an Internet search engine (e.g., Google) and a
B2C product storefront (e.g., Amazon.com). What are the roles of data mining for both applications?
(40 points)
Question 5: Relational normalization (100 points)
1. The following relational schema represents the logical design for the Comfort Inn hotel chain. Please
examine the functional dependencies and the current table structure. State clearly the highest normal form
for each of the current tables. Explain why it is in that normal form and the problems (if any) associated
with the current design. Decompose the relations to take care of these anomalies and show the process of
your conversions. Remember to mark the primary key in the new tables, and show that the problems you
pointed out earlier no longer exist. Please write down any assumptions you make.
Hotels (Phone, HotelNo, HotelName, StreetAddress, City, Zip, State, NumberOfRooms)
Guests(HotelNo, RoomNo, GLastName, GFirstName, ArriveDate, LeaveDate, NoOfBeds, RatePerDay,
OtherCharges)
3
Facilities(HotelNo, Facility, ChargeToUse)
Employees(EmpId, SSN, ELastName, EFirstName, Address, StartDate)
EmployeePosition(EmpId, Designation, Salary)
HotelNo  HotelName, StreetAddress, City, Zip, State, NumberOfRooms
Phone  HotelNo
HotelNo, RoomNo  NoOfBeds, RatePerDay
HotelNo, Facility  ChargeToUse
GuestId  GLastName, GFirstName
HotelNo, RoomNo, ArriveDate, LeaveDate  GuestId, OtherCharges
EmpId  SSN, ELastName, EFirstName, Address
SSN  EmpId, ELastName, EFirstName, Address
EmpId, StartDate  Designation, Salary
EmpId, Designation  StartDate, Salary
Question 6: Business rules (100 points)
What are the different types of business rules that can be expressed in an ER model? Give an example of
each and clearly explain why it is important to capture these business rules during conceptual design.
What is the impact of each rule on the implementation and operation of the database?
4
2002 PhD. Core Exam: Part 2
MIS Dept, Univ. of Arizona, Tucson, AZ
Wednesday, May 29, 2002
Venue: Room 214, McClelland Hall
Time: 9:00 AM – 1:00 PM
INSTRUCTIONS: (Please read them carefully before you begin the exam)
13. The exam will begin promptly at 9:00 a.m. and end promptly at 1:00 p.m. No extensions are allowed.
14. This exam consists of 6 questions. You are required to answer all of them. Please allocate roughly
30 minutes per question and leave some time for checking your answers.
15. Each question is worth 100 points.
16. For each question, state your assumptions clearly.
17. If you are writing by hand in a blue book, please answer each question in a separate blue book. If
you are using a word processor, please make sure that you start each new question on a new page.
You are allowed to use combinations of the blue book and a word processor file for answering
questions.
18. At the top of each question that you answer, please identify two things:

The number of the question that you are answering and

The code name given to you at the beginning of the exam. Do not write your real name
anywhere on the exam, and use only your code name.
19. Please make two (2) diskette copies of the files containing your answers if you are using a word
processor. Please turn in both diskettes, along with your blue book answers and the exam questions,
to the proctor at the end of the exam.
20. You are allowed to take a restroom or lunch break only if no one else is already taking one. You
should get the proctor’s consent before taking a break, and also inform him as soon as you return
from your break.
21. If you are using a word processor, please make sure that you save your answers frequently. It is your
responsibility to ensure that you do not lose work.
22. The exam is CLOSED BOOK. Accessing the web on the computer is NOT allowed and will be
severely penalized.
23. Some questions have multiple parts. Make sure you answer all of them and number them properly.
24. You have been provided with MSWORD and POWERPOINT.
GOOD LUCK!!
5
QUESTIONS 7 and 8 BELOW ARE BASED ON THE FOLLOWING NARRATIVE OF A BUSINESS
PROCESS SYSTEM
The following is a description of a TO-BE process for a music store planning to sell CDs online. The
Internet Sales System will have a database of basic information about the CDs that it can sell over the
Internet similar to the CD database at each of the retail stores. Everyday the Internet sales system will
receive an update from the distribution system that will be used to update this CD database. Some new
CDs will be added, some will be deleted and others will be revised (such as have a new price). The
electronic marketing (EM) Manager will also have the ability to create and update the information. The
sales system will also maintain a marketing database of materials about each CD that will enable online
users to learn more about them. Vendors will be encouraged to email marketing materials (music reviews,
links to Web sites, artist info, sound clips) that promote their CDs. The EM manager will go through the
emails and determine what information to place on the web. He or she will add this information to a
marketing materials database (or revise it or delete old information) that will be linked to the Website.
Customers will access the Internet Sales System to look for CDs of interest. Some customers will search
for specific CDs or CDs by specific artists whereas other customers want to browse for interesting CDs in
certain categories (e.g. rock, jazz, classical). When the customer has found all the CDs he or she wants,
the customer will check out by providing personal information (including credit card) and order
information. The system will verify the customers credit card info with an online credit card center and
either accept the order or reject it. Every hour or so, the orders will be pulled out of the order database and
sent to the distribution system. The distribution system will handle the actual sending of the CDs to
customers; however, when CDs are sent to customers (via UPS or mail), the distribution system will
notify the Internet sales system, which in turn will email the customer. Weekly reports can be run by the
EM manager to check the order status.
Question 7: (100 points)
Context Diagram
6
Functional Decomposition Diagram (Shown are 2 levels below Level 0)
A. Draw the Level 1 DFD showing interaction between processes in Level 1 of the diagram above. (30
points)
B. Illustrate the Control Flow on the above DF diagram for the following scenario: (NOTE: You may
need to develop additional levels of DFDs or integrate multiple ones for the following)
a. Processing a Customer order – (order placement through to order management) (8 points)
b. Failure notification to Manager & Customer (Non-availability of CD in inventory) (7 points)
C. Convert the above analysis into the following:
a. Identify Key objects, their methods. (at least 2 for each) (25 points)
b. What is the relationship between the above methods and the processes in the DFDs? (10 points)
c. Draw Activity (and/or) State diagrams to illustrate the scenarios in B and also highlight which key
objects may be involved. (20 points)
Question 8: (100 points)
A. Suggest a possible architecture to convert the above analysis into an implementation. For the
architecture, You need to show the following:
7
a. A list of components and for each component outline the elements of analysis that they may
contain and their functionality. (18 points)
b. A layout of the components – illustrate the control flow between the components (20 points)
c. List four qualitative properties that may be required for the overall sales system. (12 points)
d. Evaluate the style on the above properties by considering the Order processing scenario described
above. (10 points)
B. The CIO of the Music company requires the development of a strategy to implement the system with
the ability to innovate in the future, accommodate new technology, low cost overall and minimize risk
if possible. Suggest a lifecycle using one of the architectures you describe above. For each lifecycle
phase, say in a couple of lines what happens. (40 points)
Question 9: Case Study (100 points)
Assume you have just been given an opportunity to do a case study to answer some of the research
questions you posed in your 611b paper, or a phenomenon that you would like to investigate.
a) Give three (3) examples of different kinds of case studies and briefly describe the differences
between them. (10 pts)
b) Describe your case study.
(40 pts)
c) What kind of sample would you select for you study and why?
(10 pts)
d) Describe how you would go about building a theory using case study? What steps would you
take to ensure that your research is of high quality? (30 pts)
e) What are the strengths and weaknesses of doing case research?
(10 pts)
Question 10: Empirical research (100 points)
a) Why is it so important to have comparisons when conducting empirical research? Give an
example of what happens when you do not have a comparison. (35 pts)
b) According to Martin ("Doing Psychology Experiments") and others, the major advantage of a
factorial experiment is that we can study interactions. What is an interaction? Why do
interactions help in theory building? (30 pts)
c) Having read and discussed Baron & Kenny ("The Moderator-Mediator Variable Distinction in
Social Psychological Research"), what is a moderator variable? What is a mediator variable?
Give an example of each. (35 pts)
Question 11: (100 points)
A. (40 Pts.) Describe your dissertation topic or preliminary paper even if it is hypothetical. The write-up
should be in the form of an elevator speech. It should be no longer than about 30 seconds or 1 page in
length. The speech should include a description of the overall or general problem and the specific
problem you are going to solve. Your answer should reflect that you understand what makes up a good
research problem and you know how to present what you are researching.
In the 696A class we discussed the importance of having a good chart, figure or graphic.
8
B. (20 Pts.) Why is a good chart, figure or graphic important?
C. (20 Pts.) List the characteristic of a good chart, figure or graphics.
D. (20 Pts.) Give an example of an effective graphic, chart or figure. You can use a graphic from your
dissertation topic or your favorite graphic from another class.
Question 12: (100 Points)
A. (42 Pts.) Listed below are biases that often occur in experiments and research projects. Define (4 Pts.)
and give an example (3 Pts.) of:
(1.)
(2.)
(3.)
(4.)
(5.)
(6.)
Truth Bias
Hindsight Bias
Visual Bias
Availability Bias
Recency Bias
Order Bias
B. (28 Pts.) The following statement is based upon the book Fortune Sellers by William Sherden:
Predicting the future is easy if it is done right! Why? Discuss.
C. (30 points) All of the names listed in the chart below are well known contributors to the field of MIS,
Computer Science, Management or Economics. What is each researcher known for (be specific); what
organization is he/she affiliated with; also, where did he/she receive his/her graduate education? An
example is provided for you. (30 points).
Person
(Example) Sudha Ram
Points per name = 2
1. Lynda Applegate
Research Area
Data Base Systems
1 point
Current Organization
University of Arizona
½ point
Graduate Education
University of Illinois
½ point
2. Peter Chen
3. Eric Clemons
4. Gordon Davis
9
5. Gerry Desanctis
6. Sarah Kiesler
7. John King
8. Don Knuth
9. Stuart Madnick
10.Wanda Orlikowski
11. Herb Simon
12. Hal Varian
13. Andy Whinston
14. Joe Valacich
15. Robert Zmud
10