Are tests accurate?
While no assessment procedures are perfect, tests developed properly and used within the limits for which they were designed are highly accurate. Professionally developed tests are constructed on a foundation of research results and previous test outcomes that have often taken many years or decades to accumulate.
Tests can be easy to criticize, sometimes for the very reasons that they are so useful. For example, professional guidelines on test development require that the tests underlying research be described in the test users manual. This manual must include scientific evidence that makes clear both the strengths and weaknesses of the test. These days, there are few products that document their true characteristics, the strengths and weaknesses, so clearly and openly. The professionals who administer and use the test are responsible for understanding and evaluating the underlying characteristics of the test. You can ask them about these issues if you have questions.
General aptitude tests, such as the SAT in the United States, are used in certain countries as a basis for entrance into colleges and universities. A criticism associated with this use of these tests is that they are known to be subject to practice effects, and do not necessarily assess the accumulated learning of students during their schooling years. However, the goal of these tests is not to assess accumulated learning; they are designed to measure aptitude, not achievement.
Similarly, college entrance exams are criticized for not accurately predicting first-year university grade point average (GPA) as well as high school GPA. However, the intent is for test scores to be used along with other measures in university selection; large-scale test scores are only one aspect of the university selection process. Universities are free to place more emphasis on high school GPA or extracurricular activities. Any criticism might be better directed to a university than the test itself, which most people consider fair.
The content of the exam might not correspond with its intended use or representation. An example of this would be for an exam to have the ratio of questions in geometry, calculus, and number theory dissimilar to the ratio of these questions present in the environment for which the exam is intended to serve as a predictor of future performance. As an extreme and unrealistic example, a mathematics exam may ask solely about the names, birthdates, and country of origin of various mathematicians when such knowledge is of little importance in a mathematics curriculum. This need for a test to be valid for its use is AERA and NCME Standard 1.1 for educational and psychological testing. If it is used for other than its intended purpose, the burden of proof of validity rests upon its user.
People are variously susceptible to stress. Some are virtually unaffected, and excel on tests, while in extreme cases, individuals can become very nervous and forget large components of exam material. To counterbalance this, often teachers and professors don't grade their students on tests alone, placing considerable weight on homework, attendance, in-class discussion activity, and laboratory investigations (where applicable). Conversely, in some high-stakes testing cases, the pressure induces examinees to rise to meet the exam's high expectations.
Through specialized training on material and techniques specifically created to suit the test, students can be "coached" on the test to increase their scores without actually significantly increasing knowledge of the subject matter. However, research on the effects of coaching remains inconclusive, and the increase might be simply due to practice effects.
Although test organizers attempt to prevent it and impose strict penalties for it, academic dishonesty (cheating) can be used to obtain an advantage over other test-takers. On a multiple-choice test, lists of answers may be obtained beforehand. On a free-response test, the questions may be obtained beforehand, or the subject may write an answer that creates the illusion of knowledge. If students sit in proximity to one another, it is also possible to copy answers off other students, especially if a test-taker knows that particular person knows the material better than they do. Despite such issues, tests are less susceptible to cheating than other tools of learning evaluation. Laboratory results can be fabricated, and homework can be done by one student and copied by rote by others. The presence of a responsible test administrator, in a controlled environment, helps to guard against cheating.