1. to 3. Indicate which kind of model best fit(s) the example provided. Each question has at least one correct answer, and some questions may have more than one correct answer.

Kinds of Models

(A) Physical model
(B) Abstract model
(C) Sampling model

1. Model: A radio broadcast describing a military battle in Bosnia.

What it represents: The actual battle

2. Model: Craig's silver 1986 Toyota Tercel.

What it represents: Other 1986 Toyota Tercels.

3. Model: 10 potatoes that you pick out of a bin at the supermarket. After coming home you discover that 2 of these potatoes are rotten.

What it represents: The fraction of rotten potatoes in the bin.

4. Mark all of the following statements that describe physical models.

5. Which of the following statements about models are correct?

6. Which of the following statements about models are correct?

7. Your job at an advertising agency is to evaluate some data the effectiveness of an advertising campaign for the Better Burger fast food hamburger chain. These data were obtained by placing identical full page Better Burger advertisements in Vogue and Newsweek. Each ad had a coupon attached, redeemable for a free hamburger at any Better Burger location. (The coupons placed in Vogue and Newsweek could be distinguished with a very small mark, so you could tell which magazine a given coupon came from.) To analyze these data, you determine what percent of the Vogue coupons were returned, and what percent of the Newsweek coupons were returned. Because a higher percent of the Vogue coupons were returned for free hamburgers, you recommend that all future advertisement be placed in Vogue. You justify this recommendation by stating that the data suggest that an ad placed in 10,000 copies of Vogue will produce a greater number of future hamburger sales than an ad placed in 10,000 copies of Newsweek. The conclusion of this study involves use of the two models listed below. For each model, choose one answer among the eight following options that best explains what it represents. In deciding between possible answers, use the above description of how the model was used as your guide.

(A) The people who returned Newsweek coupons.

(B) Everyone who ate at Better Burger while these advertisements were running in Vogue and Newsweek.

(C) Everyone who purchased a copy of Vogue while the advertisement was running.

(D) Everyone who purchased a copy of Newsweek while the advertisement was running.

(E) Everyone who would purchase a Better Burger hamburger in response to a future advertisement you plan to run in Vogue.

(F) Everyone who would purchase a Better Burger hamburger in response to a future advertisement you plan to run in Newsweek.

(G) This model was not used in analyzing these data.

7. Model: The people who returned coupons from Vogue.

This model represents:

8. and 9. After graduation, you are hired by Jim's (a local restaurant chain), to manage their restaurant on the corner of Ben White and I-35. You want to please future customers, so you put postcards (pre-stamped) out on the tables. The postcards have several questions, including "Were the restrooms clean?", and "Would you like us to serve a wider selection of salads?" After 2 months, only 53 postcards have been returned to you, even though you know that the restaurant served 20,546 people during this 2 month period. 52 of those responding thought the restrooms were clean, and 1 didn't. And 34 of those responding thought that Jim's should not serve a wider variety of salads, and 19 thought Jim's should. Based on these responses, you decide that to satisfy the customers who will be coming to the restaurant, it is not necessary to make any changes in either the restrooms, or in the salads you serve. The above study involves use of the two models listed below. For each model, choose one answer among the eight following options that best explains what it represents. In deciding between possible answers, use the above description of how the model was used as your guide.

(A) All the customers that were served in the last two months.

(B) All future customers.

(C) All former customers.

(D) The percent of customers during the last two months that responded to a survey.

(E) The percent of customers during the last two months who thought the bathroom was clean.

(F) The percent of customers during the last two months who thought that Jim's should serve a wider selection of salads.

(G) The percent of future customers who would respond to a postcard survey.

(H) This is not a model.

8. Model: The 52 people who responded

9. Model: The 20,546 customers that Jim's served in the last two months.

10. Mr. Canton, a wheeler and dealer in [Texas real estate (A)], declares bankruptcy, much to the consternation of his many creditors. [The statement that Mr. Canton submits to the Bankruptcy Court (B)] when he declares bankruptcy summarizes his debts, assets and the litigation he is involved in. At the first meeting of creditors, Mr. Canton gives [sworn testimony regarding numerous details of his finances (C)]. (He blames his problems on his former business partner, who, conveniently enough, died recently.) Because of the bankruptcy, Mr. Canton must submit [a photocopy of his bank statement (D)] to the U.S. Trustee's office each month, and must also report on any other changes in his financial status. After [many months of delays (E)], [various legal subterfuges (F)], and increasing attorney's fees, the [Bankruptcy Court (G)] confirms a [plan of reorganization for Mr. Canton (H)]. The plan is a legally binding contract between Mr. Canton and his creditors, and it states how he is going to arrange his finances so as to pay back his creditors.

Mark all non-trivial models of Mr. Canton's financial condition (past, present or future) that are mentioned in the preceding paragraph.

11. Mark all of the following statements that describe abstract models.

 

Table of contents
Chapter 4. Models are Building Blocks in Every Scientific Approach
Chapter 5. All Models are False. But Some are Still Useful


Copyright 1996-2000 Craig M. Pease & James J. Bull. All rights reserved.
301d@bull.biosci.utexas.edu