Likert scales are helpful in social science and perception studies. High-quality tests are essential to examine the dependability of the data provided in a particular evaluation. One often-used measure of test reliability is Cronbach alpha. The dimensionality and test duration have an impact on it. The fundamentally tau-equivalent approach’s (a statistical method that measures how consistent a set of items are in a test) presumptions should be followed by alpha as a reliability indicator. If these presumptions are not met, a low alpha is shown. The Airline Service Quality (ASQ) test measures the quality of services offered by a specific airline using service attributes provided by the airline, which influence passenger satisfaction and enhance more than one-time patronage. The original instrument used measured opinions of a four-point Likert scale with fifteen airline service items, and the allowable Cronbach’s Alphas for the original test ranged from 0.70 to 0.95. By first adding a “3 represents undecided” option and then adding four-word items to the instrument, a five-point Likert scale was developed from the original instrument. The test was piloted with 33 participants.This pilot study’s Cronbach’s alpha was 0.85; following its employment in a larger research study, the instrument’s Cronbach’s alpha was 0.86, resulting in a tool with good internal consistency. Since reliability test depends on the extent of test, Cronbach alpha does not only evaluate test homogeneity or unidimensionality. Whether a test is homogeneous or not, its reliability is increased by its extent. A high alpha score (> 0.90) might indicate that the test should be shorter and may indicate redundancy.