/*! 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. R4.8 Does the herb St. John鈥檚 wort ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Q. R4.8 (page 288)

Does the herb St. John鈥檚 wort relieve major depression? Here is an excerpt from the report of one study of this issue: 鈥淒esign: Randomized, Double-Blind, Placebo-Controlled Clinical Trial.鈥� The study concluded that the difference in effectiveness of St. John鈥檚 wort and a placebo was not statistically significant.

a. Describe the placebo effect in this context. How did the design of this experiment account for the placebo effect?

b. Explain the purpose of the random assignment.

c. Why is a double-blind design a good idea in this setting?

d. Explain what 鈥渘ot statistically significant鈥� means in this context

Short Answer

Expert verified

a. As, it gave some patients a pill that should have no effect at all but looks, tastes, and feels like the Saint-John鈥檚-wort. These people think that they are being treated, but in fact, they are not. So if they get better, this would be a case of the placebo effect.

b. The purpose of this random assignment was to create two groups of subjects that are about the same in the beginning of the experiment. As this reduces bias in the conducting of the experiment.

c. Double-blind is when neither the patient or experimenter know what treatment is given. The subject should not know which treatment they are receiving so that the researchers can measure how much placebo effect there is. But the researchers should also be blinded so that they cannot influence how they measure the results.

d. 鈥淣ot statistically significant鈥� means in this context that the difference in improvement between the two groups was not large enough to rule out potential chance variation resulting for random assignment of the variables.

Step by step solution

01

Part a. Step 1. Explanation

As, it gave some patients a pill that should have no effect at all but looks, tastes, and feels like the Saint-John鈥檚-wort. These people think that they are being treated, but in fact, they are not. So if they get better, this would be a case of the placebo effect.

02

Part b. Step 1. Explanation

The purpose of this random assignment was to create two groups of subjects that are about the same in the beginning of the experiment. As this reduces bias in the conducting of the experiment.

03

Part c. Step 1. Explanation

Double-blind is when neither the patient or experimenter know what treatment is given. The subject should not know which treatment they are receiving so that the researchers can measure how much placebo effect there is. But the researchers should also be blinded so that they cannot influence how they measure the results.

04

Part d. Step 1. Explanation

鈥淣ot statistically significant鈥� means in this context that the difference in improvement between the two groups was not large enough to rule out potential chance variation resulting for random assignment of the variables.

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

Supplements for testosterone -As men age, their testosterone levels gradually decrease. This may cause a reduction in energy, an increase in fat, and other undesirable changes. Do testosterone supplements reverse some of these effects? A study in the Netherlands assigned 237men aged 60to 80 with low or low-normal testosterone levels to either a testosterone supplement or a placebo.

Explain why it was necessary to include a control group in this experiment.

Seed weight (2.2) Biological measurements of the same species often follow a normal distribution quite closely. The mean weights of seeds of a variety of winged beans are approximately normal, with a mean of 525milligrams (mg) and a standard deviation of 110mg.

a. What percent of seeds weigh more than 500mg?

b. If we discard the lightest 10%of these seeds, what is the smallest weight among the remaining seeds?

You want to take a simple random sample (SRS) of 50of the816students who live in

a dormitory on campus. You label the students 001to816in alphabetical order. In the

table of random digits, you read the entries

9559294007697693354772450166328119414873

The first three students in your sample have labels.

a.955,929,400.b.400,769,769.c.559,294,007.d.929,400,769.e.400,769,335.

Weight? Wait what? Marcos asked a random sample of 50mall shoppers for their weight. Twenty-five of the shoppers were asked directly and the other 25 were asked anonymously by means of a 鈥渟ecret ballot.鈥� The mean reported weight was13 pounds heavier for the anonymous group. Explain why the two means are so different.

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.
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Geometry

Read Explanation

Logic and Functions

Read Explanation

Applied Mathematics

Read Explanation

Statistics

Read Explanation

Decision 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.