Reply wk 4 dq 2 vt | PSY-380

Reply WK 4 DQ 2 VT 

Topic 4 DQ 2

To Set the Criteria for the Decision (step 2 in hypothesis testing) we must identify the critical value and the rejection region. What information do you need to set the criteria?

Determining the critical region which will yield results sufficient to reject the null hypothesis and avoid a Type II error is an important part of the hypothesis test (Gravetter et al., 2021). In order to determine this region, it is important to know the initial population mean and standard variation, as well as the expected sample number and the expected effect size (Gravetter et al., 2021). By using the expected effect size, one can simulate the alternative hypothesis distribution (what it would look like if the effect were real) and see where it falls in relation to the original distribution (which would stay the same if the null hypothesis were true). Whatever portion of the alternative distribution falls past the z-score of +- 1.96 would represent the proportion of samples that would be sufficient evidence of a treatment effect (Gravetter et al., 2021).

With the information referenced above, one could find the exact point on the distribution that would mark the critical point of when sample values would cross the alpha level threshold. This value is called M critical and is calculated using the null hypothesis mean, the z score of the alpha level and the standard deviation for the sample distribution (standard error value) (Gravetter et al., 2021). Once the critical point is determined, the z-score for THAT point is computed, and the corresponding proportion on the unit normal table represents the probability or power of the test.

How do you determine when to use a one-tailed test? When do you use a two-tailed test?

A one tailed test is only used when there is evidence supporting a directional prediction, such as prior research (Gravetter et al., 2021). If the researchers are confident that the effect can only increase or only decrease the mean, they may use a one tailed test. The one tailed test uses the same alpha level, but as the proportion of the distribution is not split between the two sides, the z-value associated with the critical region is 1.65 and will only occur on one side of the distribution (Gravetter et al., 2021). This can potentially increase the power of the hypothesis test because there is a larger critical region, but it also makes it more likely that a Type I error will occur, where a treatment effect is detected when there is none (Gravetter et al., 2021). In other words, the evidence could be misleading.

A two tailed test is considered more rigorous, as the alpha level split between two tails makes the z-score boundary for the critical regions + or – 1.96 z (Gravetter et al., 2021). In situations where the treatment effect is unknown, or there is a possibility that it may either increase or decrease the mean, it is important to use a two tailed test in order to detect all effects. Additionally, when a researchers wants to decrease their likelihood of getting a Type I error, they may use a two tailed test to make the critical region smaller (Gravetter et al., 2021). Ironically, this may potentially increase Type II error, because there is a possibility that a treatment effect may be missed because it is too small to be detected. In this scenario, it would be important that the researcher increase the power of their hypothesis in other ways, such as increasing the sample size.

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
The price is based on these factors:
Academic level
Number of pages
Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more

STAY HOME, SAVE LIVES. Order your essay today and save 20% with the discount code ATOM