/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q. 84 In the experiment of the precedi... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Q. 84 (page 268)

In the experiment of the preceding exercise, the subjects were randomly assigned to the

different treatments. What is the most important reason for this random assignment?

a. Random assignment eliminates the effects of other variables such as stress and body

weight.

b. Random assignment is a good way to create groups of subjects that are roughly

equivalent at the beginning of the experiment.

c. Random assignment makes it possible to make a conclusion about all men.

d. Random assignment reduces the amount of variation in blood pressure.

e. Random assignment prevents the placebo effect from ruining the results of the study.

Short Answer

Expert verified

Option b is correct answer: Random assignment is a good way to create groups of subjects that are roughly equivalent at the beginning of the experiment.

Step by step solution

01

Given Information

We need to find out reason for random assignment to different treatments in preceding exercise.

02

Explanation

In an experiment, random assignment is used to assign people to the control and treatment groups by chance. This procedure ensures that the groups are equal at the start of the investigation, making it safer to assume that the treatments are to blame for any differences observed by the experimenters at the end. As a result option b is correct answer.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Growing in the shade- The ability to grow in shade may help pine trees found in the dry forests of Arizona to resist drought. How well do these pines grow in shade? Investigators planted pine seedlings in a greenhouse in either full light, light reduced to 25% of normal by shade cloth, or light reduced to 5% of normal. At the end of

the study, they dried the young trees and weighed them. Identify the experimental units and the treatments.

Side effects Even if an experiment is double-blind, the blinding might be compromised if side effects of the treatments differ. For example, suppose researchers at a skin-care company are comparing their new acne treatment against that of the leading competitor. Fifty subjects are assigned at random to each treatment, and the company鈥檚 researchers will rate the improvement for each of the 100subjects. The researchers aren鈥檛 told which subjects received which treatments, but they know that their new acne treatment causes a slight reddening of the skin. How might this knowledge compromise the blinding? Explain why this is an important consideration in the experiment.

You wonder if TV ads are more effective when they are longer or repeated more often

or both. So you design an experiment. You prepare 30-second and 60-second ads for a

camera. Your subjects all watch the same TV program, but you assign them at random

to four groups. One group sees the 30-second ad once during the program; another sees

it three times; the third group sees the 60-second ad once; and the last group sees the

60-second ad three times. You ask all subjects how likely they are to buy the camera.

Which of the following best describes the design of this experiment?

a. This is a randomized block design, but not a matched pairs design.

b. This is a matched pairs design.

c. This is a completely randomized design with one explanatory variable (factor).

d. This is a completely randomized design with two explanatory variables (factors).

e. This is a completely randomized design with four explanatory variables (factors).

Funding for fine arts The band director at a high school wants to estimate the percentage

of parents who support a decrease in the budget for fine arts. Because many parents attend

the school鈥檚 annual musical, the director surveys the first 30parents who arrive at the

show. Explain how bias in the sampling method could affect the estimate.

Foster care versus orphanages Do abandoned children placed in foster homes do better than similar children placed in an institution? The Bucharest Early Intervention Project found statistically significant evidence that they do. The subjects were 136young children abandoned at birth and living in orphanages in Bucharest, Romania. Half of the children, chosen at random, were placed in foster homes. The other half remained in the orphanages. (Foster care was not easily available in Romania at the time and so was paid for by the study.) What conclusion can we draw from this study? Explain your reasoning.

See all solutions

Recommended explanations on Math Textbooks

Probability and Statistics

Read Explanation

Applied Mathematics

Read Explanation

Mechanics Maths

Read Explanation

Calculus

Read Explanation

Discrete Mathematics

Read Explanation

Logic and Functions

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.