Question

11) a. In a designed​ experiment, what are the experimental​ units?
b. If the experimental units are​ humans, what term is often used in place of experimental​ unit?
a. Choose the correct answer below.

A.
The group receiving placebo
B.
The group receiving the specified treatment
C.
The individuals or items on which the experiment is performed
D.
The experimental conditions

12) In a designed​ experiment, there is one factor with four levels. How many treatments are​ there?

Choose the correct answer below.

A.
There are four treatments.
B.
There are sixteen treatments.
C.
There is one treatment.
D.
There are three treatments.

13) A magazine reported on the​ "... treatment-emergent adverse events that occurred in​ 2% or more patients treated with a new medicine and with incidence greater than placebo in the treatment of​ depression, OCD, or​ bulimia." In the​ study, 2434 patients took the new medicine and 1396 patients were given placebo. Identify the a. treatment​ group, b. control​ group, and c. treatments.

a. Which of the following is the treatment​ group?

A.
The 2434 patients who took the new medicine
B.
The new medicine
C.
The 1396 patients who took placebo
D.
The placebo
E.
The 3830 patients who took part in the study

A​ driver's ability to detect highway signs is an important consideration in highway safety. In his​ dissertation, S. Younes investigated the distance at which drivers can first detect highway caution signs. This distance is called the detection distance. Younes analyzed the effect that sign size and sign material have on detection distance. Drivers were randomly assigned to one combination of sign size​ (small, medium, and​ large), and sign material​ (1, 2, and​ 3). Each driver covered the same stretch of highway at a constant speed during the same time of​ day, and the detection​ distance, in​ feet, was determined for the​ driver's assigned caution sign. Complete parts​ (a) through​ (e) below.

a. Identify the experimental units. Select all that apply.

A.
the time of day
B.
the sign material
C.
the drivers
D.
the detection distance
E.
the sign size
F.
the driving speed

       
14) In a​ study, the effects of the mane of a male lion as a signal of quality to mates and rivals was explored. Four​ life-sized dummies of male lions provided a tool for testing female response to the unfamiliar lions whose manes varied by length​ (long or​ short) and color​ (blonde or​ dark). The female lions were observed to see whether they approached each of the four​ life-sized dummies. Complete parts​ (a) through​ (e) below.

a. Identify the experimental units. Choose the correct answer below.

The mane colors
The mane lengths
The male dummies
The female lions

15) In an​ experiment, the effect of using either a conventional or experimental mouthwash was investigated. Eighteen female and 18 male preschoolers were selected. Within each gender​ group, nine were randomly assigned to the conventional mouthwash and the remaining nine to the experimental mouthwash. After each subject rinsed with the assigned mouthwash​, a dental plaque index was measured. The higher the dental plaque​ index, the greater was the amount of plaque on an​ individual's teeth.
a. Is the statistical design described here a completely randomized design or a randomized block​ design? Explain your answer.
b. If the statistical design is a randomized block​ design, what are the​ blocks?

a. What kind of design is​ described?

A.
The experiment is a randomized block design because the experimental units​ (the students) were first blocked by gender and then randomly assigned to the treatments​ (the different kinds of mouthwash​).
B.
The experiment is a completely randomized design because the experimental units​ (the students) were all randomly assigned to the treatments​ (the types of mouthwash​).
C.
The experiment is a completely randomized design because the experimental units​ (the mouthwashes​) were all randomly assigned to the treatments​ (the genders of the​ students).
D.
The experiment is a randomized block design because the experimental units​ (the students) were first blocked by mouthwash and then randomly assigned to the treatments​ (gender).
E.
The experiment is a randomized block design because the experimental units​ (the mouthwashes​) were first blocked by the gender of the students and then randomly assigned to the treatments​ (the mouthwash ​type).
F.
The experiment is a randomized block design because the experimental units​ (the mouthwashes​) were first blocked by mouthwash type and then randomly assigned to the treatments​ (the genders of the​ students).

Answer 1

The experimental unit is the physical entity which can be assigned, at random, to a treatment.

11)

The experimental​ units are,
C.
The individuals or items on which the experiment is performed

12)

The treatments are equivalent to the levels of factor.

A.
There are four treatments.

13)

a.

The treatment​ group is,

A.
The 2434 patients who took the new medicine

The experimental units are
C.
the drivers

       
14)

The experimental units is,
The female lions

15)

The kind of design is​,

A.
The experiment is a randomized block design because the experimental units​ (the students) were first blocked by gender and then randomly assigned to the treatments​ (the different kinds of mouthwash​).