Measurement is the process of quantifying the attribute or characteristic of something with the help of a standardized tool of measurement. When we measure a particular attribute of something we convert it into numerical values. Usually standardized units of measurement are used for this purpose. For example when we measure the length of something we convert it into meters, and when we measure the weight of something we convert it into grams. Similarly, in education, when we measure the academic achievement or learning outcomes (which may be any positive change in the leanings or skills of a student as a result of a particular educational program or activity) of a student we convert them into test scores. We know that learning is a relatively permanent change in the behavior of a student through experience and instruction. This change may be big or small, simple or complex. Some changes can be measured while some may be hard to measure. But if a change is important and big enough to be noticed it may be measured. And a student with sufficient amount of it will be different from a student with less amount of it. As far as the accuracy of the data obtained through various tools of measurement is concerned, it depends on two things, the validity and reliability of the tools used for the measurement and the experience of those who use these tools. If a tool is not valid and reliable, or if those who use this tool have no experience in its use, then its results may not be accurate and reliable. Educational measurement helps us in educational assessment and evaluation.
