The test is applicable and appropriate in carrying out comparative studies of observations and measurements to establish their reliability in a given study. The test correlates different findings of the two groups of observers or two sets of instruments to determine their variability and subsequently their reliability in the study. Split-half is a reliability test that assesses variability of the findings based on two groups of observers or two sets of instruments. Moreover, the use of different instruments and conducting multiple experiments is very expensive. High internal consistency of the study means that low external validity, which makes it difficult to extrapolate findings to apply in the general populations. The weaknesses of internal consistency are that they reduce the external validity of the findings and it is very expensive to conduct. Since instruments have inherent errors that can affect the results, the use of different instruments or carrying out multiple experiments enhances internal consistency and reduces the effect of confounding variables in the study. The strengths of internal consistency are that they enhance the accuracy of the results by eliminating possible errors that are inherent in the instrument and reduce the effect of confounding variables in a study. The test is appropriate when analyzing the effectiveness of parameters or instruments in a given study. The internal consistency reliability test employs multiple experiments or tests and correlates measurements to establish if instruments or the parameters are consistent in measuring the same construct. Internal consistency is a reliability test that seeks to ascertain if consistencies exist in parameters that measure a certain construct. Tests of Reliability Internal consistency Difficult to determine causal relationships

Test validity and reliability