ABSTRACT
Item-total analysis is a way to assess the internal consistency of a data set. As such, it is one of many tests of reliability. Item-total analysis comprises a number of items that make up a scale or a test designed to measure a single construct (e.g., intelligence), and it determines the degree to which all of the items measure the same construct. It does not tell you if it is measuring the correct construct (that is a question of validity). Before a test can be valid, however, it must first be reliable. Assumptions
All the items in the scale should be measured on an interval or ratio scale. In addition, each item should be normally distributed. If your items are ordinal in nature, you can conduct the analysis using the Spearman rho correlation instead of the Pearson r correlation.
