Reliability refers to the extent to which a series of similar assessments are consistent in the result they give (Rubin & Babbie, 2010). This is a crucial aspect of carrying out tests which may be a way of testing bias as well as distortion. For instance, this can be tested in an actual situation with a DNA test. A DNA test that needs to show if a suspects DNA matches a sample at a crime scene. To ensure that the scale is reliable, the sample can be tested twice and if the results are consistent both times then the test is reliable. There are types of reliability; stability or test- retest, alternate form and internal consistency as Rose (2013) asserts.
On the other hand, validity refers to the accuracy level of an assessment. In other words it is a determination of whether an assessment accomplishes the set purpose of measuring what it was supposed to measure as Rubin & Babbie (2010) acknowledge. In research these two aspects are very crucial for the result to be good and accurate. Despite their difference in meaning, the two aspects are essential when both are put into consideration. For example, fingerprint matching is a good way of testing validity of a result. This for instance can be in a case where a person …show more content…
Therefore, they should be considered together for the best result. However, if these factors are considered separately in measurement, reliability is more important that reliability. This is mainly due to the fact that when the measure of an aspect is reliable, it automatically becomes valid. If one gets consistent results then the measurements they get are both reliable and valid. In some cases data collected may be valid but not reliable. In such a case the results are useful in coming up with conclusions of the test. However, reliable data can be considered valid as it is consistent with what is