First, the test-and retest instrument is used to analyze the reliability of the psychological instrument by focusing on its time component. The instrument evaluates a group for a measure and utilizes the same measure in the future, as well as establishing a correlational analysis to see if there is divergence or inconsistency (Fishman & Galguera, 2003). You will notice that the dependability difference is often great while it is small and grows over time. An instrument may be used to evaluate specific variables. Then it’s used in the same research one to twelve months later in order to identify variations and inconsistencies.
By having multiple independent judges rate the scores, Inter-rater evaluates the reliability and validity of the psychological instrument. Kline, 2005. To determine if the scores are comparable or if ratings and opinions differ between them (inter-rater) In this case, several people will be asked to evaluate the exact same instrument. Then their opinions and comparisons are made. The reliability is determined by the consistency of the results.
You can also use the parallel-form reliability to evaluate instrument dependability. The parallel form dependability compares two results generated by the same instrument (Fishman & Galguera, 2003). This instrument compares the results from identically-quality items that have been subject to separate testing.