Question

Spam filters in an email program are similar to hypothesis tests in that there are two possible decisions and two possible realities and therefore two kinds of errors that can be made. The hypotheses can be considered as:

H0: Incoming email message is legitimate.
Ha: Incoming email message is spam.

Suppose an incoming legitimate message is flagged by the spam filter and sent to the spam folder. What type of error did the spam filter make?

Select one:

a. Type II error
b. No error was made
c. Type I error

Answer 1

Option C) Type I error

Explanation:

We are given the following in the question:

`H_0:\text{Incoming email message is legitimate.}\\H_a: \text{Incoming email message is spam.}`

Type I error:

• It is also known as false positive.
• It is the rejection of a true null hypothesis.

Type II error:

• It is known as false positive.
• It is the acceptance of a false alternate hypothesis.

An incoming legitimate message is flagged spam by a spam filter.

Thus, a true null hypothesis that the message is legitimate is rejected and the message is send to spam folder.

Thus, spam filter made a

Option C) Type I error