Introduction

Hand versus
computer
analysis

Coding

Data entry

Aids

Key terms

Main points

1. When you have a small sample and only a few variables, tallying or counting responses by hand may be the easiest way to analyze your data. For larger samples with many variables, computer-based analysis, using a statistical analysis package, will save a lot of tedious calculating and many errors.
2. To use a statistical analysis package, all data must be put in numerical form through a process of coding. Coding can also help if you decide to do analyses by hand. Coding is the process of assigning numbers in a proscribed manner to the attributes of variables.
3. Closed items may be coded at the time the responses are constructed, called precoding, or may be done as part of the process of preparing data for analysis.
4. In coding, variables are given a short, abbreviated name. Giving names to variables is essential for computer analysis. Also, numbers are assigned to the attributes making up each variable. This information together with the definitions of variables is entered into a codebook. A codebook is a directory to the variables and their codes.
5. When computer analysis is used, a data file has to be created. This identifies the locations of variables in the memory of the computer and provides the codes used for their attributes. This information is necessary for planning analyses and for interpreting what you find.
6. Coding open-ended items or other qualitative data requires developing a limited set of categories that are mutually exclusive, exhaustive, and that have high face or content validity. Generally, between 3 and 7 categories work well.
7. Reliability of coding is established by demonstrating agreement among independent coders. Called inter-analyst reliability, this form of agreement establishes the reliability of the coding scheme. In addition, the reliability of the main coder should be demonstrated. This form of reliability is called intra-analyst reliability.
8. Codes can be prepared for data entry into the computer in several ways. Codes can be copied on to transfer sheets that show the codes for each variable in a series of columns or by use of edge coding. The latter is accomplished by copying codes in the blank margin of the questionnaire opposite responses. Edge coding can also help when hand tallying is used.
9. When computer analysis is used, it is necessary to check the accuracy of codes for all entries in the data file. This process of data cleaning can be done by inspecting a printout of all codes and by being alert to inconsistencies among codes for variables.