/*! 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 R4.9. An herb for depression? Does the... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Q R4.9. (page 273)

An herb for depression? Does the herb Saint-John鈥檚-wort relieve major depression? Here is an excerpt from the report of a study on this issue: 鈥淒esign: Randomized, double-blind, placebo-controlled clinical trial.鈥�62 The study concluded that the herb is no more effective than a placebo.

(a) How did the design of this experiment account for the placebo effect?

(b) Why is a double-blind design a good idea in this setting?

Short Answer

Expert verified

Part (a) The placebo effect would occur if the drugs improved their condition.

Part (b) Researchers should also be blinded so they are unable to check out the influence.

Step by step solution

01

Part (a) Step 1: Given information

A placebo is more effective than an herb.

02

Part (a) Step 2: Concept

A placebo isan inactive treatment, sometimes called a 'sugar pill.

A placebo (false therapy) is given to a control group in several investigations. This reduces confusion caused by the placebo effect, in which some patients improve because they expect the treatment to work while receiving an inert treatment.

03

Part (a) Step 3: Explanation

A placebo has been said to be more effective than a herb.

If patients are given a medication that tastes and looks just like Saint John's wort, but it has no effect, it is considered a failure. Patients might believe they were being treated when, in fact, they were not. The placebo effect would occur if the drugs improved their condition.

04

Part (b) Step 1: Explanation

Both the researcher and the volunteers must remain unaware of the treatment they are receiving. Researchers should also be blinded in this case to prevent them from detecting the influence.

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

Technology for teaching statistics The Brigham Young University (BYU) statistics department is performing experiments to compare teaching methods. Response variables include students鈥� final-exam scores and a measure of their attitude toward statistics. One study compares two levels of technology for large

lectures: standard (overhead projectors and chalk) and multimedia. There are eight lecture sections of a basic statistics course at BYU, each with about 200students. There are four instructors, each of whom teaches two sections. Suppose the sections and lecturers are as follows:

(a) Suppose we randomly assign two lecturers to use standard technology in their sections and the other two lecturers to use multimedia technology. Explain how this could lead to confounding.

(b) Describe a better design for this experiment.

Sampling the forest To gather data on a 1200-acre pine forest in Louisiana, the U.S. Forest Service laid a grid of 1410 equally spaced circular plots over a map

of the forest. A ground survey visited a sample of 10% of these plots.12

(a) Explain how you would use technology or Table D to choose an SRS of 141 plots. Your description should be clear enough for a classmate to obtain your results.

(b) Use your method from (a) to choose the first 3 plots.

The Web portal AOL places opinion poll questions next to many of its news stories. Simply click your response to join the sample. One of the questions

in January 2008 was 鈥淒o you plan to diet this year?鈥� More than 30,000 people responded, with 68% saying 鈥淵es.鈥� You can conclude that

(a) about 68% of Americans planned to diet in 2008

(b) the poll used a convenience sample, so the results tell us little about the population of all adults.

(c) the poll uses voluntary response, so the results tell us little about the population of all adults.

(d) the sample is too small to draw any conclusion.

(e) None of these.

The manager of a sports arena wants to learn more about the financial status of the people who are attending an NBA basketball game. He would like to give a survey to a representative sample of the more than 20,000fans in attendance. Ticket prices for the game vary a great deal: seats near the court cost over \(100each, while seats in the top rows of the arena cost \)25each. The arena is divided into 30numbered sections, from 101to 130Each section has rows of seats labeled with letters from A (nearest the court) to ZZ (top row of the arena).

Explain why it might be difficult to give the survey to an SRS of 200 fans.

Effects of binge drinking A common definition of 鈥渂inge drinking鈥� is 5 or more drinks at one sitting for men and 4 or more for women. An observational study

finds that students who binge drink have lower average GPA than those who don鈥檛. Identify a lurking variable that may be confounded with the effects of binge drinking. Explain how confounding might occur.
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Mechanics Maths

Read Explanation

Logic and Functions

Read Explanation

Probability and Statistics

Read Explanation

Geometry

Read Explanation

Pure Maths

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.