Proxy measurement is the method of determining certain outcomes using calculable quantities or values when you do not have the ability to measure the exact value. This mode gauges progress of activities or research, predicting probable results.
Proxy describes and defines the procedure of acquiring the proxy measures. Proxy is related to the Latin word procuratia or procuratio which means substitute agent or authorized stand in. This word is a neighbor to the word Latin approximatus which translates as to draw near to or to be close to. The definition of proxy then makes you conclude that the measures used would not be entirely accurate, but would be close to the actual measures. Proxy measures use the computable data to ascertain criteria to decide on a particular outcome or the probability of a certain outcome. This process can be complicated since the parameters to judge results are varied.
We can look at a practical example to help clarify the meaning of proxy measures. For a psychologist who needs to evaluate the success of a prison rehabilitative program, he would have several criteria at his disposal to decide on the possible outcomes. As a result, the proxy measures to be incorporated into the study would be the inmate demographics, return offender rates, number of offenders who made probation, probationers who violated probation terms and community services participation.
Reliability and Consistency
To attain correct conclusions through proxy measures, you have to ensure that you have a degree of reliability which means that the calculable information must reflect cases which express the same phenomenon or situation. The information or indicators have to be consistent. For example, based on the above case, the success of the rehabilitative program has to be equivalent to the length of time that an ex-prisoner remains outside of jail.