A classification essay is written to organize objects into categories basing upon a unique organizing principle and giving examples that fit into each selected category. A classification essay should therefore begin with the identification of the appropriate categories. For example, in case it is necessary to classify the package of letters, one might identify the following categories: business letters, personal letters, and trash.
Thesis statement of the classification essay should be formulated accordingly: it should contain brief description of the selected topic and identify the primary classification categories. Sample thesis statement of the classification essay may look as follows: “Contemporary civil aviation consists of jet airplanes, supersonic airplanes and multipurpose helicopters". The writer should carefully consider the categories to be sure that no critical category is missed. For example, classification essay about civil aviation that contains no information about jet airplanes will be incomplete, as jet airplanes accomplish the major part of medium- and long-range transportations in the contemporary civil aviation. The writer should also follow the selected classification principle and avoid illogical classification principles. For example, while classifying the civil aviation it is illogical to include the classification of jet airplanes by size or range as this is more of a jet airplanes classification than civil aviation classification. It is ultimately important to support each identified category with a sufficient quantity of perceivable examples, whereby the most important category might require more examples and elaboration. The primary features of a classification essay are:

-efficient organization into categories;
-adherence to the single classification principle;
-listing a sufficient number of examples for each identified category.