Statistics

A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its use and a planned diet for six weeks. The other half of the group is given the same diet without the herb. A nurse at the nutrition center weighs each subject on Friday of each week. Select the potential source of confounding.
A. The placebo effect

B. Method of assignment to treatment and control groups

C. Experimenter effect

D. The study is essentially free of confounding sources


is it B

  1. 0
  2. 0
  3. 13
asked by Amy
  1. I disagree.

    1. 0
    2. 0
    posted by Ms. Sue
  2. An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.

    A dependent variable is the response or measure of results.

    Extraneous variables — other than the independent variable — potentially can affect the dependent variable, so they must be controlled. If possible, you try to keep them constant between the experimental and control group.

    The experimental group receives the independent variable.

    The control group is similar to experimental, except it does not receive the independent variable. Extraneous variables are balanced between experimental and control groups.

    1. 0
    2. 0
    posted by PsyDAG
  3. well it can't be D or A placebo because it refers to the situation in which patients improve simply because they believe they are receiving a useful treatment.

    im left with C

    1. 0
    2. 0
    posted by Amy
  4. How does the experimenter affect the study?

    1. 0
    2. 0
    posted by Ms. Sue
  5. 1. Single blind gives the control group a placebo — a substance that is inert, it has no physical effect. Subjects don't know if they are in experimental or control group to reduce placebo effect, a change in behavior solely due to believing that you are getting the independent variable.

    2. Double blind keeps both subjects and experimenter ignorant of group setup. Distribution of the independent variable and placebo are controlled by third party. This controls for experimenter bias and self-fulfilling prophecy, which means that experimenters with particular expectations are likely to consciously or unconsciously to bias the experiment and influence it to conform to their expectations.

    As an example, suppose you want to find out if fluorides reduce dental cavities. You would find two groups, trying to control the extraneous variables. Extraneous variables are found by surveying previous research in the area. In this case, you would match the groups in terms of previous history of cavities, diet and dental hygiene habits including how and how often they brush their teeth.

    The experimental group would get toothpaste with the independent variable, the fluoride, while the control group would not have the fluoride in their toothpaste. The toothpaste without the fluoride would be the placebo.

    The dependent variable would be the number of cavities after participating in the experiment for a time. The dependent variable indicates the results, but it is not the results. At the end of the experiment, both groups could have no change in cavities or one of the groups could have a greater reduction in cavities. (Of course, if the fluoride increased cavities, you wouldn't want to use it.) All of these varied results would be indicated in terms of the dependent variable.

    If only the subjects do not know who is getting the fluoride, it is a single blind experiment. If both the subjects and experimenter do not know, it is a double blind.

    1. 0
    2. 0
    posted by PsyDAG

Respond to this Question

First Name

Your Response

Similar Questions

  1. Stats

    A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its
  2. Statistics

    A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its
  3. statistics

    A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its
  4. Stats - Help!!!

    A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its
  5. Psychology 220

    1.68 (1 pts.) In order to evaluate the effectiveness of a new psychotherapeutic technique, Dr. Schwartz is testing the therapy on clients that have sought treatment from him at his private practice. According to Martin Seligman,
  6. Stats

    A study found that for adults the general self-efficacy scale mean score was 35 and standard deviation was 12. A group of clients (n=14) was measured for their general self-efficacy with the same measure and found having 40 with
  7. english

    in lamb to the slaughter mary maloney represents a feminist who undergoes total metamorphosis. validate the sentence reflecting on her conduct in the story?
  8. Social Psychology

    Throughout our lives, we are measured by the people and circumstances around us. However, the most important measurement is our own. How we view and feel about ourselves impacts our level of life satisfaction. Much of our world is
  9. social psychology

    Throughout our lives, we are measured by the people and circumstances around us. However, the most important measurement is our own. How we view and feel about ourselves impacts our level of life satisfaction. Much of our world is
  10. math 9 ALGERBRA!!! HELP! please

    elenear is three years older than herb. in twelve years the sum of their ages will be 51. how old is herb today? i did this so far but i don't know what to do next? let x represent herb's age x+3 represent elenear's age

More Similar Questions