Scales of Measurement

1.

A researcher examines whether scores on a homework assignment are influenced by whether

background music is soft, loud, or absent.

a.

What is the independent variable?

b.

Is the independent variable manipulated or not manipulated?

c.

How many levels are there for the independent variable?

d.

What is the dependent variable?

e.

What is the scale of measurement for the dependent variable?

2.

A researcher compares freshmen, sophomores, juniors, and seniors with respect to how

much fun they have while attending college (1=no fun at all, 7=maximum amount of

fun).

a.

What is the independent variable?

b.

Is the independent variable manipulated or not manipulated?

c.

How many levels are there for the independent variable?

d.

What is the dependent variable?

e.

What is the scale of measurement for the dependent variable?

3.

In the criminal justice system, a defendant is innocent until proven guilty. Therefore, the

null hypothesis is: “This person is innocent.”

a.

In this case, what would be the Type I error?

b.

In this case, what would be the Type II error?

c.

Which do you think is the more costly error? Why?

4.

In one famous study (Rosenhan, 1973), eight healthy volunteers (“pseudopatients”)

presented themselves to psychiatric hospitals. They told the admissions officers that they

had been hearing voices. Except for this one lie, they answered all other questions

truthfully. All pseudopatients were admitted to the hospitals, where they ceased to

pretend they were hearing voices (in other words, they behaved ‘normally’). None of the

pseudopatients were detected as sane. Rosenhan argued that the staff at the hospitals

seemed to be operating under the null hypothesis that patients in a psychiatric hospital are

insane.

a.

In this study, did the hospital staff commit a Type I or Type II error in calling

sane patients insane?

b.

Which would be the more costly error? Why