Garden with Insight v1.0 Help: qualitative/quantitative

Strictly speaking, qualitative differences are differences in quality, like the difference between blue and green, while quantitative differences are differences in quantity, like the difference between 450 and 500.

However, the line between qualitative and quantitative differences is blurry, often depending on where you concentrate your attention. The difference between blue and green is identical, in fact, to the difference between 450 and 500 nanometer wavelengths of light. We often use the word "qualitative" to describe differences or trends that are easily observable or large, even though they may be quantifiable if you really try. In contrast a quantitative difference or trend is usually considered to be small. For example, if you and your sister are ten years apart in age, there is a qualitative difference in your ages. If you and your sister are ten days apart in age, there is a quantitative difference in your ages.

This distinction is often used in simulation to describe two things: 1) variation in nature (qualitative differences are much more important to include in a simulation); 2) simulation results. If the results of a simulation show roughly the same trend as those in reality (plants have an S-shaped curve of growth, for example), we might say the results are or qualitatively accurate.

This is an important distinction for a teaching model such as this, because while we do not expect our results to be quantitatively accurate (and thus usable to predict farming practices) like the original EPIC results are, we do except the results to be qualitatively accurate to the extent that you can learn something about the way things work in a typical garden.