Re: to classmates

Mary

Re: Topic 4 DQ 2

In statistics, tests are used to make decisions about parameters in a population (Privitera, 2015). A two-tailed test is an example of a non-directional test. These are “hypothesis tests in which the alternative hypothesis is stated as not equal to a value stated in the null hypothesis. Hence, the researcher is interested in any alternative to the null hypothesis.” (Privitera 2015, page 241). This type of test can be used when comparing IQ scores of graduate students and members of the general, healthy population (Privitera, 2015). On the other hand, an alternative to this would be a directional test: a one-tailed test. This is when “the alternative hypothesis is stated as greater than or less than a value stated in the null hypothesis. Hence, the researcher is interested in a specific alternative to the null hypothesis.” (Privitera 2015, page 244). This type of test can be used to evaluate whether a school program, such as a reading program, improves reading skills as it is designed to do (Privitera, 2015). Two-tailed tests are used when the researcher has no idea which way the data may go, whereas one-tailed tests are used when the researcher generally knows which way the data are going to go (PSY-380 Topic 4 Reading). Because the z test is not a common hypothesis test, there is not a direct way to compute it in SPSS (Privitera, 2015).

 

Terry

Re: Topic 4 DQ 2

One- tailed tests are used when the alternative hypothesis is either less than or greater than the value stated in the null hypothesis. A one-tail test is used to prove that data is either greater than or less than the mean. This would occur when you are trying to prove that scores would increase or decrease. When there are hypothesis tests where the alternative hypothesis is not equal to the value that the null hypothesis states. This is when a two-tailed test is used, the alpha is split and half of the results are placed in each tail of a normal distribution. Two-tailed test are used for nondirectional data, just looking at the shift of the data from the mean. SPSS is able to provide output analyses that shows the significance of the hypothesis. It can be used to put in the information that is needed to compute the effective size and even power.

Reference

Christy  

Re: Topic 4 DQ 2

A one-tailed test is also called a directional test, it is a hypothesis test where the alternative hypothesis is stated as greater than or less than a value put forth in the null hypothesis. A researcher may use this when they are looking for a specific alternative in the null hypothesis. The two-tail test is also called the nondirectional test; this is where the alternative hypothesis is described as not equal to the null hypothesis. This test is used when looking for any alternative to the null hypothesis (Privitera, 2015).

The SPSS is used for most statistic tests used in behavioral research but it is not used in a z test hypothesis test being the value of the population variance is rarely known. SPSS can provide analyses to show the significance of a hypothesis test and the effect size and even power. You can find step by step instructions for test input. (Privitera, 2015).

 

Privitera, G. (2015) Statistics for the behavioral sciences (2nd ed.). Los Angeles, CA: SAGE. ISBN-13: 9781483381169 

Hello Professor & Class,

A one-tailed test are used when a alternative hypothesis is less or greater than the value that is stated in the null hypothesis. When we are using the one tailed test  it is used to prove that the data is either greater or less than the mean. When that occurs it's because you are trying to prove that the scores will either decrease or increase.  We could use a hypothesis tests but the problem with that is the alternative hypothesis will not equal to the null hpothesis. So the two-tailed test is being used. When we are using the two-tailed test it is designed to examine both sides of a data range. SPSS is  used toshow the hypothesis.

-Chaz