There are home schooling advertisements on television which seemingly are deceptive. One advertisement states that with their teaching materials, a pupil achieved from the second to the fifth grade level in reading in a few short months. It would be interesting to notice which measurement instrument was utilized to measure such great achievement in a few months. The average pupil will achieve one grade level in one normal school year. Reputable standardized tests must have high validity; thus the test needs to measure its intentions and in this situation reading achievement, not mathematics nor other curriculum area. Additionally, the test needs to measure what was taught in school, such as phonics if this is what preceded from reading instruction. The Manual of the standardized test will describe how validity was determined. Also, the test must be reliable in measuring consistently. Thus, if a pupil measures being on the fifth grade level in reading, would the same or similar score be obtained if tested again using the same test? The test results would tell us nothing about the pupil's progress if he/she measures the second grade level in reading in the first test administration and fifth grade level the second time of administration within a short interval of time. These two concepts, validity and reliable, are poignant in metrics and measurement of learner achievement.
Do all reputable achievement tests measure the same/similar objectives of instruction? They may differ in what is being measured. For instance, a good standardized test may focus more on one of the following as compared to another in reading instruction;
* word recognition as in using phonics or using context clues
* critical or literal comprehension
* creative thinking or problem solving.
It is very important to choose a high quality standardized test to measure pupil achievement be it for home schooling results or for the regular school setting!
— Marlow Ediger, North Newton