Cronbach alpha is a reliability test conducted within spss in order to measure the internal consistency i. Click the options button, and check variance under. The reliability analysis procedure calculates a number of commonly used measures of scale reliability and also provides information about the relationships between individual items in the scale. Spss also gives the standardized slope aka, which for a bivariate regression is identical to the pearson r. Creating graphs in spss this tutorial will show you how to explore. What is the distribution of a companys customers by industry type. It is most commonly used when the questionnaire is developed using multiple likert scale statements and therefore to determine if the scale is reliable or not. The rankin paper also discusses an icc 1,2 for a reliability measure using the average of two readings per day. The table below shows the observed pollution indexes of air samples in two areas of a city.
Analysing data using spss sheffield hallam university. In a test of the reliability of products produced by two machines, machine a produced 15 defective parts in a run of. For data measured at nominal level, eg agreement concordance by 2 health professionals of classifying patients at risk or not at risk of a fall, use of cohens kappa test based on the chisquared test is made. A score of 90 on an invalid or unreliable test would be no different from a score of 50. By default spss aligns numerical data entries to the.
Reliability analysis allows you to study the properties of measurement scales and the items that compose the scales. Using spss to understand research and data analysis. The analyses reported in this book are based on spss version 11. The t test in this example tests the hypothesis that there is no difference in clerks beginning and current salaries. You can see then even in this simple example that different types of data can lend themselves to different types of analysis. A handbook of statistical analyses using spss food and.
Checking normality in spss university of sheffield. How to test reliability method alpha using spss spss tests. Now, you should have reverse scored item 3 see above. There are versions of spss for windows 98, 2000, me, nt, xp, major unix platforms solaris, linux, aix, and macintosh. For example, you could use an independent ttest to understand whether first year graduate salaries differed based on gender i. To that end, it is necessary to test the validity and reliability to determine whether the instrument used in the study are valid and reliable. Stepbystep instructions on how to run a sign test in spss statistics using a relevant example. Nonparametric statistical procedures are less powerful because they use less information in their calculation.
Sign test in spss statistics procedure, output and interpretation of. Independent ttest in spss statistics procedure, output and. The slope is given in the b column to the right of the name of the x variable. Statistical hypothesis testing worksheet and normality checking example solutions worksheet. If an instrument lacks validity or reliability, the meaning of individual scores becomes otiose. Descriptive and inferential statistics department of statistics. Reliability analysis on spss lets test the reliability of the saq using the data in saq.