Study Guide

Field 081: Computer Science
Sample Constructed-Response Assignment

The following materials contain:

Test Directions for the Constructed-Response Assignment

This section of the test consists of one constructed-response assignment. You are to prepare a written response of approximately 300–600 words on the assigned topic. You should use your time to plan, write, review, and edit your response to the assignment.

Read the assignment carefully before you begin to write. Think about how you will organize your response.

As a whole, your response must demonstrate an understanding of the knowledge and skills of the field. In your response to the assignment, you are expected to demonstrate the depth of your understanding of the content area through your ability to apply your knowledge and skills rather than merely to recite factual information.

Your response to the assignment will be evaluated on the basis of the following criteria:

PURPOSE: the extent to which the response achieves the purpose of the assignment
SUBJECT MATTER KNOWLEDGE: accuracy and appropriateness in the application of subject matter knowledge
SUPPORT: quality and relevance of supporting details
RATIONALE: soundness of argument and degree of understanding of the subject matter

The constructed-response assignment is intended to assess subject matter knowledge and skills, not writing ability. However, your response must be communicated clearly enough to permit valid judgment of the scoring criteria. Your response should be written for an audience of educators in this field. The final version of your response should conform to the conventions of edited American English. Your written response must be your original work, written in your own words, and not copied or paraphrased from some other work.

Be sure to write about the assigned topic. You may not use any reference materials during the test. Remember to review what you have written and make any changes you think will improve your response.

Sample Constructed-Response Assignment

Subarea III
Program Design and Algorithms
Read the information below; then complete the exercise that follows.

A computer programmer needs to write a program that will operate a bank's automatic teller machine (ATM). Each of the bank's customers has a checking and/or a savings account. All savings accounts earn interest on the entire balance, while only checking accounts with balances over $1,000 earn interest on the entire balance. Checking accounts have a monthly service fee, while savings accounts do not. To access his or her accounts, a customer enters his or her personal identification number (PIN). Once the PIN has been validated, the customer can choose to make a deposit, make a withdrawal, or transfer funds between accounts. Customers can perform an unlimited number of transfers from checking to savings accounts, but the number of transfers from savings to checking is limited to five per month. The program needs to calculate the interest earned by the accounts and update the balances in each account as necessary. It also needs to update the cash balance of the ATM.

The program needs to store the following data:

Write a response that demonstrates your conceptual understanding of an object-oriented approach to solving this problem, using the principle of inheritance. In your response:

Sample Strong Response to the Constructed-Response Assignment

Please note: The sample response provided below is for review purposes only and should not be used in a response on an operational exam. Use of the exact words and phrases presented in this sample response will result in a score of "U" (Unscorable) due to lack of original work.

The main classes that need to be developed for this application are ATM, Customer, Account, and CheckingAccount and SavingsAccount, which are derived from the class Account.

There would also be a data structure that keeps track of the list of customers.

ATM

Data – keeps track of

Methods – performs the following transactions

Interacts with the Customer and Account classes and the data structure that holds the list of customers

Customer

Data – keeps track of

Interacts with the CheckingAccount and the SavingsAccount classes

Account

Data – keeps track of

Methods – performs the following transactions

CheckingAccount

(derived from Account)

Data – keeps track of

Methods – performs the following transactions

SavingsAccount

(derived from Account)

Data – keeps track of

Methods – performs the following transactions

This program design uses the principle of inheritance by defining a superclass Account with two subclasses, SavingsAccount and CheckingAccount. Both subclasses inherit the data members and functionality from Account and do not need to redefine them. In addition to the members inherited from Account, CheckingAccount would also include the service fee and would override the method in Account to calculate the interest on checking accounts with the appropriate balance. SavingsAccount needs to keep track of the number of transfers from SavingsAccount to CheckingAccount, since the number of transfers is limited to five per month.

Performance Characteristics

The following characteristics guide the scoring of responses to the constructed-response assignment.

Characteristics that guide the scoring of responses
Purpose The extent to which the response achieves the purpose of the assignment
Subject Matter Knowledge The accuracy and appropriateness in the application of subject matter knowledge
Support The quality and relevance of supporting details
Rationale The soundness of argument and degree of understanding of the subject matter

Scoring Scale

Scores will be assigned to each response to the constructed-response assignment according to the following scoring scale.

Score Scale with description for each score point.
Score Point Score Point Description
4  start bold The "4" response reflects a thorough knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is fully achieved.
  • There is a substantial, accurate, and appropriate application of subject matter knowledge.
  • The supporting evidence is sound; there are high-quality, relevant examples.
  • The response reflects an ably reasoned, comprehensive understanding of the topic.
3  start bold The "3" response reflects a general knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is largely achieved.
  • There is a generally accurate and appropriate application of subject matter knowledge.
  • The supporting evidence generally supports the discussion; there are some relevant examples.
  • The response reflects a general understanding of the topic.
2  start bold The "2" response reflects a partial knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is partially achieved.
  • There is a limited, possibly inaccurate or inappropriate application of subject matter knowledge.
  • The supporting evidence is limited; there are few relevant examples.
  • The response reflects a limited, poorly reasoned understanding of the topic.
1  start bold The "1" response reflects little or no knowledge and understanding of the subject matter. end bold 
  • The purpose of the assignment is not achieved.
  • There is little or no appropriate or accurate application of subject matter knowledge.
  • The supporting evidence, if present, is weak; there are few or no relevant examples.
  • The response reflects little or no reasoning about or understanding of the topic.
U The response is unscorable because it is illegible, not written to the assigned topic, written in a language other than English, or lacking a sufficient amount of original work to score.
B There is no response to the assignment.