Session 4- Learning to use the SPSS

We did a survey in the afternoon. The what is happening in this course survey. We have to work in the original groups to do the work. Later we are to find put about Cronbach Alpha Reliability and Paired-sample t-test.

What then is cronbach alpha reliability?
It is measurement to test internal consistency of a test. Then what is internal consistency?
In statistics and research, internal consistency is a measure based on the correlations between different items on the same test (or the same subscale on a larger test). It measures whether several items that propose to measure the same general construct produce similar scores. For example, if a respondent expressed agreement with the statements, "I like to ride bicycles," "I've enjoyed riding bicycles in the past," and "I hate bicycles" (this item would be reverse scored), our test would have good internal consistency.

Internal consistency is usually measured with Cronbach's alpha, a statistic calculated from the pairwise correlations between items. A commonly-accepted rule of thumb is that an α of 0.6-0.7 indicates acceptable reliability, and 0.8 or higher indicates good reliability. Note that extremely high reliabilities (0.95 or higher) are not necessarily desirable, as this indicates that the items may be not just consistent, but redundant.( taken from Wikipedia)

This is what I found out about the t-test from Wikipedia.
A t-test is any statistical hypothesis test in which the test statistic has a Student's t distribution if the null hypothesis is true. It is applied when sample sizes are small enough that using an assumption of normality and the associated z-test leads to incorrect inference.

Read about paired sample t-test on this site
Read about Cronbach Alpha reliability