STEPS 4 : SCREENING, CLEANING AND PREPARE DATA

SCREENING, CLEANING AND PREPARE YOUR DATA

Data screening is one of the most important steps. Here is where all possible outliers will be removed in order to ensure the accuracy of data. We may perform unintended error by wrongly key in the data, which will give a significant effect on the data set.

In relation to this data entry, the following steps have been performed to identify the possible outliers.

1. Select Analyze and Frequencies
2. Insert the variable
3. Click the Statistics button
4. Click Continue and OK

Figure 1: However, in our data there is no missing data or ouliers. Therefore, we will directly proceed to Transform and Compute the data.

After completed the process of data entry and screening the data, it is necessary to have two new variables which are :

1. Total Score of Memory Functioning Self-Report (TotMFS) 
2. Total Score of Epworth Sleepiness (TotESS)

By looking at the word "TOTAL", it indicates that all scores for each scale should be added. There could be so many possible error or unintended mistakes if the calculation was done manually. Therefore, the calculation process is so much easier by using SPSS. 

By selecting "TRANSFORM" in the menu bar, and "Compute Variable", the process of adding the total score can be operated as illustrated below:

Then, in the next window, we inserted all score for Memory Functioning Self-Report items and labelled it as "TotMfs1"

  
And, the new variable of TotMfs1 is as shown below:

  
Then, The same procedures were operated for the second scale which is Total Score of Epworth Sleepiness (TotESS). However, we are conducting A Paired Sample T-test, thus we will have four total scores from 2 scales. 1) TotMfs1 & TotMfs2, 2)TotEss1 & TotEss2. The Example as shown below: