Click here for a brief explanation of the different types of measurement scales. The information will give you a little more context for the preceding section.
Assessment is a process by which information is obtained relative to some known objective or goal. Assessment is a broad term that includes testing. A test is a special form of assessment. Tests are assessments made under contrived circumstances especially so that they may be administered. In other words, all tests are assessments, but not all assessments are tests. We test at the end of a lesson or unit. We assess progress at the end of a school year through testing, and we assess verbal and quantitative skills through such instruments as the SAT and GRE. Whether implicit or explicit, assessment is most usefully connected to some goal or objective for which the assessment is designed. A test or assessment yields information relative to an objective or goal. In that sense, we test or assess to determine whether or not an objective or goal has been obtained. Assessment of skill attainment is rather straightforward. Either the skill exists at some acceptable level or it doesn’t. Skills are readily demonstrable. Assessment of understanding is much more difficult and complex. Skills can be practiced; understandings cannot. We can assess a person’s knowledge in a variety of ways, but there is always a leap, an inference that we make about what a person does in relation to what it signifies about what he knows. In the section on this site on behavioral verbs, to assess means To stipulate the conditions by which the behavior specified in an objective may be ascertained. Such stipulations are usually in the form of written descriptions.
Evaluation is perhaps the most complex and least understood of the terms. Inherent in the idea of evaluation is “value.” When we evaluate, what we are doing is engaging in some process that is designed to provide information that will help us make a judgment about a given situation. Generally, any evaluation process requires information about the situation in question. A situation is an umbrella term that takes into account such ideas as objectives, goals, standards, procedures, and so on. When we evaluate, we are saying that the process will yield information regarding the worthiness, appropriateness, goodness, validity, legality, etc., of something for which a reliable measurement or assessment has been made. For example, I often ask my students if they wanted to determine the temperature of the classroom they would need to get a thermometer and take several readings at different spots, and perhaps average the readings. That is simple measuring. The average temperature tells us nothing about whether or not it is appropriate for learning. In order to do that, students would have to be polled in some reliable and valid way. That polling process is what evaluation is all about. A classroom average temperature of 75 degrees is simply information. It is the context of the temperature for a particular purpose that provides the criteria for evaluation. A temperature of 75 degrees may not be very good for some students, while for others, it is ideal for learning. We evaluate every day. Teachers, in particular, are constantly evaluating students, and such evaluations are usually done in the context of comparisons between what was intended (learning, progress, behavior) and what was obtained. When used in a learning objective, the definition provided on the ADPRIMA site for the behavioral verb evaluate is: To classify objects, situations, people, conditions, etc., according to defined criteria of quality. Indication of quality must be given in the defined criteria of each class category. Evaluation differs from general classification only in this respect.
To sum up, we measure distance, we assess learning, and we evaluate results in terms of some set of criteria. These three terms are certainly share some common attributes, but it is useful to think of them as separate but connected ideas and processes.
Here is a great link that offer different ideas about these three terms, with well-written explanations. Unfortunately, most information on the Internet concerning this topic amounts to little more than advertisements for services.