Correlation and recoding variables using SPSS.
Get ‘EDUC298 ATS' data-file of Attitudes toward Statistics from blackboard, and do the followings:
produce new variables of M1, M2, M3, M4, M5, & M6 by recoding item30, item31, item32, item33, item34, item35 into dichotomous variables (1 = correct answer, 0 = incorrect answer). (Note: The correct answers on the math items are 3, 5, 3, 5, 4, & 2)
Produce a composite math score by summing the new math variables. Name it ‘Mtotal' (total score on math).
Recode negatively worded items. These items are 2, 4, 6, 7, 10, 12, 14, 15, 16, 18, 20, 25, 27, and 28. The values of the items would be changed as follows: 5 to 1; 4 to 2; 3 to 3; 2 to 4; 1 to 5.
Make a composite variable summing all the items (Q1 to Q29) and name it ‘Atotal'.
1. Classify the variables of Q37, Q42, Mtotal, and Atotal as continuous or categorical. Report the measures of central tendency (Mean and Median) and variability (Variance and Standard Deviation) for each continuous variable. Report the Mode and Percentages for categorical variables.
2. Plot a stem-and-leaf plot and boxplot for Mtotal. Show the hand calculation of median location and upper hinge location of boxplot, and find their corresponding data values.
3. Plan a histogram for Atotal.
4. Report a correlation coefficient between the variables of Mtotal and Atotal. Graph relationship and interpret it.