FEBRUARY, 2013 BY: ABDUL-RAUF A TRAINING WORKSHOP ON STATISTICAL AND PRESENTATIONAL SYSTEM SOFTWARE (SPSS) 18.0 WINDOWS

Introduction  Mathematics is the language of science, data analysis is the language of research  As long as there is research, there will be the need to analyze data  SPSS - Statistical and Presentational System Software  SPSS 17 and 18 are called PASW (Predictive Analytics SoftWare)  What is SPSS?  A software package use for conducting statistical analysis, manipulating data, and generating tables and graphs. SeTRAC

Getting to know SPSS  Option 1:  Place your cursor on the SPSS icon and double click  Option 2:  Step 1: Click on Start  Step 2: Move cursor to All Programmes  Step 3: Click on SPSS executable file to open  Step 4: Click on the option under ‘What would you like to do’?  E.g Open existing data source  Step 5: Click OK button SeTRAC

Features of SPSS  The main window features include: Data Editor  Data view and Variable view The Viewer The Pivot Table Editor Chart Editor SeTRAC

Entering data  Step 1: Click on Data View  Step 2: Click on the first cell (1 st C, 1 st R)  Step 3: Type in the # e.g. if the variable is ID, then type in 1  Step 4: Move the cursor into the second cell and enter second piece of information for case # 1  Step 5: Move the cursor into next cell and enter very piece of information for case # 1  Step 6: Press the Home key to get back. Use the down arrow to move to the second row and enter data for case #2 SeTRAC

Modifying the data file  To delete a case  To insert a case between existing cases  To delete a variable  To insert a variable between existing variables  To move an existing variable  To sort the data file  To split the data file  To select cases SeTRAC

To insert a variable between existing variables  Step 1: Position your cursor in a cell in the column (variable) to the right of where you would like the new variable to appear  Step 2: Right click  Step 3: Insert variable  Step 4: Enter the data of the new variable SeTRAC

To move an existing variable  Step 1: Create a new empty variable column  Step 2: Click on the variable name of the existing variable you wish to move  Step 3: Click on the Edit menu and choose Cut  Step 4: Highlight the new empty column that you created  Step 5: Click on the Edit menu and choose Paste SeTRAC

Screening and cleaning the data  Data screening process involves a # of steps:  Step 1: Checking for errors  Step 2: Finding the error in the data file  Step 3: Correcting the error in the data file SeTRAC

Checking for errors  Inspect the frequencies for Categorical variables  Click on Analyze  Click on Descriptive Statistics  Click Frequencies  Choose the variable you wish to check (e.g. sex)  Move these into the Variables box  Click on Continue  Click on OK SeTRAC

Checking for errors cont.  I nspect the frequencies for Continuous variables  Click on Analyze  Click on Descriptive Statistics  Click Descriptives  Choose the variable you wish to check (e.g. age)  Move these into the Variables box  Click on Continue  Click on OK SeTRAC

Checking for errors cont.  Step 1: Check your minimum, maximum and means values  Step 2: Check the number of valid and missing cases  Step 3: Check the frequencies fall into each category eg district, community, etc  Step 4: Delete on your keypad SeTRAC

Finding the error in the data file  METHOD 1  Step 1: Click on the variable name of the variable in which the error has occurred (e.g. a 3 for sex)  Step 2: Click once to highlight the column  Step 3: Click on Edit from the menu across the top of the screen  Step 4: click on Find  Step 5: In the Search for box, type in the incorrect value that you are looking for (e.g 3)  Step 6: Click on Search Forward to continue SeTRAC

Finding the error in the data file  METHOD 2  Step 1: Click on Analyze, Descriptive Stat. Explore  Step 2: In the Display section click on Statistics  Step 3: Click on e.g. sex and move to Dependent list  Step 4: In the Label cases, choose ID  Step 5: In the Statistics section choose Outliers  Step 6: Click on Continue  Step 7: In the Options section choose Exclude case pairwise  Step 8: Click on Continue and then OK SeTRAC

Correcting the error in the data file  Step 1: Check what value should have been entered for that person  Step 2: Find the variable labelled ID  Step 3: Move down to the case that has the ID # with the error  Step 4: Move across the row until you come to the column of the variable with the error  Step 5: Place the cursor in the cell, type in the correct value SeTRAC

Obtaining frequency for categorical variable  Step 1: Click on Analyze, Descriptive Statistics, Frequency  Step 2: Choose and highlight the categorical variables you are interested in  Step 3: Move these into the Variables box  Step 4: Click on the Statistics button  Step 5: In the Dispersion section tick Minimum and Maximum  Step 6: Click on Continue and OK SeTRAC

Obtaining descr. stat. for continuous variable  Step 1: Click on Analyze, Descriptive Statistics, Descriptives  Step 2: Click on all the continuous variables that you wish to obtain descriptive statistics for  Step 3: Click on the arrow button to move them into the Variables box  Step 4: Click on the Options button  Step 5: Click on mean, standard deviation, minumum, maximum, skewness, kurtosis  Step 6: Click on Continue, and OK SeTRAC

Cross tabulation  Step 1: Click on Analyze, Descriptive Statistics, Cross tabs  Step 2: Click on (sex)  Step 3: Click on Row arrow button to move into Row(s) section  Step 4: Click on (agegp3)  Step 5: Click on Column arrow button to move into Column(s)  Step 6: Click on Cells SeTRAC

Crosstab cont.  Step 7: Click on Expected, Total, Unstandardized  Step 8: Click on Continue  Step 9: Click on OK SeTRAC

Creating graphs e.g. histogram  Step 1: Click on Graphs, Histogram  Step 2: Click on your continuous variable of interest (Total perceived stress)  Step 3: Move it into the Variable box  Step 4: Click on Display normal curve  Step 5: Click on Title to type the desired title  Step 6: Click on Continue and OK SeTRAC

Bar graph  Step 1: Click on Graph, Bar  Step 2: Click on Clustered  Step 3: In the Data in chart are section, click on Summaries for groups of cases  Step 4: Click on Define  Step 5: In the Bars represent box click on Other statistics/summary function  Step 6: Click on the continuous variable (Total perceived stress)  Step 7: Click on categorical variable (agegp3) SeTRAC

Bar graph cont.  Step 8: Click on the arrow button to move it into the Category axis box  Step 9: Click on another categorical variable (sex)  Step 10: Move it into the Define Clusters by box  Step 11: Click on the Options button  Step 12: Remove tick if any from Display groups defined by missing values  Step 13: Click on OK SeTRAC

Creating a scatterplot  Step 1: Click on Graphs, Scatter  Step 2: Click on Simple, Define  Step 3: Click on your dependent variable (Total perceived stress)  Step 4: Click on the arrow to move it into the box labelled Y axis  Step 5: Move your other variable into the box labelled X axis  Step 6: Move categorical variables into the Set Markers by box  Step 7: Click on Title, Continue and then OK SeTRAC

Editing a chart/graph  Step 1: Double click on what you wish to change  Step 2: Click on the title or label you wish to change  Step 3: Click once on the aspect of the chart/graph that you wish to change  Step 4: Click on the button on the menu bar that corresponds to the aspect you wish to change SeTRAC

Non-parametric techniques  There are many techniques of non- parametrics  Chi-square for independence  Mann-Whitney Test  Wilcoxon Signed Rank Test  Kruskal-Wallis Test  Friedman Test  Spearman Rank Order Correlation SeTRAC

Procedure for Spearman’ Rank Order Cor.  Step 1: Click on Analyze, Correlate, Bivariate  Step 2: Click on your two variables (total PCOISS, total perceived stress)  Step 3: Move them into the box marked Variables  Step 4: In the section labelled Correlation Coefficients  Step 5: Click on the option labelled Spearman  Step 6: Click on OK SeTRAC

THE END THANK YOU FOR YOUR ATTENTION SeTRAC