Of course, you could claim that the distances are equal, but how do you know all or even most respondents will see them as equal. All responses will be based their perceptions of the distances between each adjective. So, you can see that the numerical weights you assign to each adjective is arbitrary. Each scale is as arbitrary as the next. The reason this is important is because whether the data generated by the survey are on an interval scale or not determines the particular kind of statistical tests you should use to analyze your data.
Most surveyors use descriptive statistics to provide general analysis of the response data.
The most common descriptive statistics are the mean, variance, standard deviation, range, frequency counts, and percentage distribution. The mathematical computations for these statistics will work regardless of the kind of data you input, however. So, by using nominal or ordinal data in computing the mean will yield a result, but it may not necessarily be a true, or meaningful result. Consider the following example. You send out a survey containing one question to 100 people.