This topic contains a solution. Click here to go to the answer

Author Question: Briefly explain the confounds of instrumentation and mortality. What will be an ideal ... (Read 54 times)

tsand2

  • Hero Member
  • *****
  • Posts: 520
Briefly explain the confounds of instrumentation and mortality.
 
  What will be an ideal response?

Question 2

Under what circumstances is a stratified random sample the most appropriate sampling method?
 
  What will be an ideal response?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Athena23

  • Sr. Member
  • ****
  • Posts: 305
Answer to Question 1

Instrumentation is a threat to internal validity in which changes in the dependent variable may be due to changes in the measuring device. Mortality, or attrition, is a threat to internal validity in which differential dropout rates may be observed in the experimental and control groups, leading to inequality between the groups.

Answer to Question 2

A stratified random sample is appropriate when researchers want to describe and compare different subgroups that make up a population. This type of sampling ensures that each subgroup will be represented with a guaranteed number of participants. Note, a stratified random sample is a probability sample, so the entire population must be known.




tsand2

  • Member
  • Posts: 520
Reply 2 on: Jun 19, 2018
Wow, this really help


  • Member
  • Posts:
Reply 3 on: Yesterday
Gracias!

 

Did you know?

There are immediate benefits of chiropractic adjustments that are visible via magnetic resonance imaging (MRI). It shows that spinal manipulation therapy is effective in decreasing pain and increasing the gaps between the vertebrae, reducing pressure that leads to pain.

Did you know?

Street names for barbiturates include reds, red devils, yellow jackets, blue heavens, Christmas trees, and rainbows. They are commonly referred to as downers.

Did you know?

Increased intake of vitamin D has been shown to reduce fractures up to 25% in older people.

Did you know?

People with high total cholesterol have about two times the risk for heart disease as people with ideal levels.

Did you know?

Tobacco depletes the body of vitamins A, C, and E, which can result in any of the following: dry hair, dry skin, dry eyes, poor growth, night blindness, abscesses, insomnia, fatigue, reproductive system problems, sinusitis, pneumonia, frequent respiratory problems, skin disorders, weight loss, rickets, osteomalacia, nervousness, muscle spasms, leg cramps, extremity numbness, bone malformations, decayed teeth, difficulty in walking, irritability, restlessness, profuse sweating, increased uric acid (gout), joint damage, damaged red blood cells, destruction of nerves, infertility, miscarriage, and many types of cancer.

For a complete list of videos, visit our video library