Essays, classified as non-objective tests, allow for the assessment of higher-order thinking skills. Such tests require students to organize their thoughts on a subject matter in coherent sentences in order to inform an audience. In essay tests, students are required to write one or more paragraphs on a specific topic.
Essay questions can be used to measure the attainment of a variety of objectives. Stecklein (1955) has listed 14 types of abilities that can be measured by essay items:
- Comparisons between two or more things
- The development and defense of an opinion
- Questions of cause and effect
- Explanations of meanings
- Summarizing of information in a designated area
- Knowledge of relationships
- Illustrations of rules, principles, procedures, and applications
- Applications of rules, laws, and principles to new situations
- Criticisms of the adequacy, relevance, or correctness of a concept, idea, or information
- Formulation of new questions and problems
- Reorganization of facts
- Discriminations between objects, concepts, or events
- Inferential thinking
Note that all these involve the higher-level skills mentioned in Bloom’s Taxonomy.
The following are rules of thumb which facilitate the scoring of essays:
Rule 1: Phrase the direction in such a way that students are guided on the key concepts to be included.
Example: Write an essay on the topic: “Plant Photosynthesis” using the following keywords and phrases: chlorophyll, sunlight, water, carbon dioxide, oxygen, by-product, stomata.
Note that the students are properly guided in terms of the keywords that the teacher is looking for in this essay examination. An essay such as the one given below will get a score of zero (0). Why?
Nature has its own way of ensuring the balance between food producers and consumers. Plants are considered producers of food for animals. Plants produce food _for animals through a process called photosynthesis. It is a complex process that combines various natural elements on earth into the final product which animals can consume in order to survive. Naturally, we all need to protect plants so that we will continue to have food on our table. We should discourage the burning of grasses, cutting trees, and illegal logging. If the leaves of plants are destroyed, they cannot perform photosynthesis and animals will also perish.
Rule 2: Inform the students on the criteria to be used for grading their essays. This rule allows the students to focus on relevant and substantive materials rather than on peripheral and unnecessary facts and bits of information.
Example: Write an essay on the topic: “Plant Photosynthesis” using the keywords indicated. You will be graded according to the following criteria: (a) coherence, (b) accuracy of statements, (c) use of keywords, (d) clarity and (e) extra points for innovative presentation of ideas.
Rule 3: Put a time limit on the essay test.
Rule 4: Decide on your essay grading system prior to getting the essays of your students.
Rule 5: Evaluate all of the students’ answers to one question before proceeding to the next question. Scoring or grading essay tests question by question, rather than student by student, makes it possible to maintain a more uniform standard for judging the answers to each question. This procedure also helps offset the halo effect in grading. When all of the answers on one paper are read together, the grader’s impression of the paper as a whole is apt to influence the grades he assigns to the individual answers. Grading question by question, of course. prevents the formation of this overall impression of a student’s paper. Each answer is more apt to be judged on its own merits when it is read and compared with other answers to the same question. than when it is read and compared with other answers by the same student.
Rule 6: Evaluate answers to essay questions without knowing the identity of the writer. This is another attempt is control personal bias during scoring. Answers to essay questions should be evaluated in terms of what is written, not it terms of what is known about the writers from other contacts with them. The best way to prevent our prior knowledge from influencing our judgment is to evaluate each answer without knowing the identity of the writer. This can be done by having the students write their names on the back of the paper or by using code numbers in place of names.
Rule 7: Whenever possible, have two or more persons grade each answer. The best way to check on the reliability of the scoring of essay answers is to obtain two or more independent judgments. Although this may not be a feasible practice for routine classroom testing, it might be done periodically with a fellow teacher (one who is equally competent in the area). Obtaining two or more independent ratings becomes especially vital where the results are to be used for important and irreversible decisions, such as in the selection of students for further training or for special awards. Here the pooled ratings of several competent persons may be needed to attain level of reliability that is commensurate with the significance of the decision being made.
Some teachers use the cumulative criteria i.e. adding the weights given to each criterion, as basis for grading while others use the reverse. In the latter method, each student begins with a score of 100. Points are then deducted every time a teacher encounters a mistake or when a criterion is missed by the student in his essay.