Question

Authorizing computer users with palm prints. Access to computers, email, and Facebook accounts is achieved via a password—a collection of symbols (usually letters and numbers) selected by the user. One problem with passwords is that persistent hackers can create programs that enter millions of combinations of symbols into a target system until the correct password is found. An article in IEEE Pervasive Computing (October-December 2007) investigated the effectiveness of using palm prints to identify authorized users. For example, a system developed by Palmguard, Inc. tests the hypothesis

\({H_0}\): The proposed user is authorized

\({H_a}\): The proposed user is unauthorized

by checking characteristics of the proposed user’s palm print against those stored in the authorized users’ data bank.

a. Define a Type I error and Type II error for this test. Which is the more serious error? Why?

Short answer

1. Type II error is the more serious

Step-by-step solution

Given Information

The null and alternative hypothesis are given by

\({H_0}\): The proposed user is authorized

\({H_a}\): The proposed user is unauthorized

Type I error

In this case, Type 1 error happens when the user is labeled as unauthorized in spite of authorized.

Type II error

In this case, Type II error indicates that an unauthorized user would be considered authorized.

• An unauthorized may commit significant damage to the data that the security system is designed to defend whereas an unauthorized user presumably has alternative, safe methods of obtaining access.
  Hence, Type II error is the more serious.