Avoid embedded blanks . In most statistical software, an embedded blank will cause the software to presume that you are referring to two variables. SPSS, for example, gets confused when you ask for a histogram for mom age and will try instead to product two histograms, one for mom and one for age . Here's where the underscore comes in handy. Compare this to the alternative, momage , which looks like a nonsense word rhyming with homage.
Some packages are case insensitive.
SPSS, for example, will convert your variable name to all lower case. Here's what the data set looks like with variable names. If you have categorical data, assign a code to each category level. Use the code during data entry to save time and minimize errors. While I prefer to use number codes, there are some advantages to using short letter codes .