SERVQUAL modifications validity

As it has already been explained, one of the main reasons for selecting the SERVQUAL model as the survey instrument is because it has a good reliability and validity record. The techniques used to develop the measuring instrument were thorough and vigorous with the validity and reliability of the scales well documented (Parasuraman et al. 1985, 1988, 1991 and Zeithaml et al. 1990). Therefore, only the modifications applied to the model for the purpose of this research require validation. These modifications are:

1. the adaptation of the items to be included in the survey instrument in order to capture the industry’s specific requirements (recommended by the model’s creators); and

2. the duplication of the expectations’ rating column for measuring passengers’ expectations for both their flying airline and alliance.

In section 3.4.6.1, a number of criteria that have been employed for the application of the SERVQUAL model in the aviation industry were presented. The reasons for disregarding certain aviation-specific items included in previous studies (Kearney, 1986; Kloppenborg and Gourdin, 1992; Li and Chen, 1998; Chang and Yeh, 2002; Young, Cunningham and Lee, 1994) were presented.

The selected items employed for the passengers’ survey represent the existing items of the SERVQUAL model, with small wording changes to make them specific to the aviation industry. These changes were originally adapted by Sultan and Simpson (2000) and are presented in the following table.

Original Items Aviation Items

modern-looking equipment modern-looking aircraft visually appealing facilities visually appealing cabin neat appealing employees neat appealing aircrew materials associated with service visually appealing comfortable seat

the service is delivered by the time promised on-time performance

perform the service right the first time fast baggage-handling

provide their services at the time promised fast check-in

service at convenient times convenient schedules

Parasuraman et al 1985; 1990, 1991 and Zeithaml el al 1990 Sultan and Simpson 2000

Personal care Customers' interest at heart

Understand specific needs Feel safe Consistently courteous Good knowledge to answer questions

Individual attention willingness to help Unchanged Items

Always respond to requests Behaviour instill confidence

Table 3.1: Original and Aviation-Specific SERVQUAL Items

interest in soliving problem

well-informed of service details prompt service to customers

From Table 3.1 it can be observed that only 8 out of the 21 original SERVQUAL items were changed for the purpose of this study. As it can be seen, all of the adapted items are measuring the same aspect of the service as the original items but have been reworded in order to either sound better (e.g. “convenient times” became “convenient schedules”) or to become more aviation-specific (e.g. “modern-looking equipment” became “modern looking aircraft”).

The validation of the expectations’ column duplication required a pilot survey. The objective of this pilot survey was to provide evidence that the duplication of the expectations column in the same survey instrument would provide the same results as if the airline and alliance expectations would have been measured in different survey instruments. For this reason, 2 versions of the survey instrument were developed. Both versions represent the original SERVQUAL model but differ between them in the sense that the first version measures airline expectations, whereas the second version measures alliance expectations.

The pilot survey was also carried out at Athens International Airport. A sample of airlines was then selected in order to test the validity of the modified SERVQUAL model in compared with the original SERVQUAL model-versions. The largest airline

selected (Lufthansa from the Star Alliance, Air France from SkyTeam and British Airways from Oneworld) as the dominant airlines of the three global alliances.

The same sample size requirements applied in the passengers’ survey (3.4.8.2) were also employed for the pilot survey. Moreover, if evidence from the pilot survey suggests that the modified SERVQUAL model produces the same results as the original SERVQUAL model (validate the modification), then the results for the 3 selected airlines from the modified model can also be used in the passengers’ survey analysis.

The steps carried out for validating the modified SERVQUAL model include:

1. Identify the expectation items with statistical differences between the modified and original SERVQUAL models using the ANOVA test;

2. Identify the homogeneity for the identified items with the Levine Test in order to decide appropriate test: Games-Howell when equal variances are not assumed or LSD when equal variances are assumed;

3. Carry out Post-Hoc test to identify statistical significant differences between the modified and original SERVQUAL expectation items.

It should be noted that no statistical significant differences were identified between the items of the original and the modified SERVQUAL models, providing evidence that the simultaneous measurement of passengers’ airline and alliance expectations does not affect their respective scores and therefore the validity of the modified SERVQUAL model is not affected.

The following three tables (3.2: Lufthansa; 3.3: Air France; and 3.4: British Airways) present the airline and alliance expectation scores derived from both the original and modified SERVQUAL models. As it can be observed from these tables, no significant differences were identified.

Sign. Sign.

Item Original Modified Dif. Original Modified Dif.

Modern looking aircraft 1.60 1.53 1.75 1.78

Visually appealing cabin 1.72 1.70 1.78 1.80

Neat appealing aircrew 1.64 1.63 1.71 1.75

Comfortable seat 1.83 1.85 1.89 1.88

On-time performance 1.47 1.45 1.50 1.53

Staff interest in solving problems 1.74 1.75 1.72 1.70

Fast baggage handling 1.58 1.58 1.77 1.75

Fast check-in 1.58 1.58 1.77 1.80

Well informed of service details 1.60 1.58 1.74 1.78

Prompt service to customers 1.67 1.68 1.72 1.75

Willingness to help 1.66 1.68 1.61 1.58

Always respond to requests 1.79 1.80 1.85 1.83

Behaviour that instill confidence 1.89 1.88 1.81 1.80

Feel safe 1.46 1.45 1.42 1.40

Consistently courteous 1.81 1.83 1.85 1.83

Good knowledge answer questions 1.68 1.65 1.90 1.95

Individual attention 1.80 1.83 1.92 1.95

Convenient schedules 1.83 1.80 1.92 1.95

Personal care 1.70 1.68 1.70 1.68

Customers' interest at heart 2.15 2.13 2.17 2.20

Understand specific needs 1.80 1.78 1.89 1.90

Airline Expectations Airline Expectations

Table 3.2: Lufthansa Pilot Survey Results

Sign. Sign.

Item Original Modified Dif. Original Modified Dif.

Modern looking aircraft 1.95 1.92 2.07 2.10

Visually appealing cabin 1.92 1.88 2.05 2.05

Neat appealing aircrew 1.79 1.77 1.85 1.90

Comfortable seat 1.65 1.62 1.71 1.77

On-time performance 1.69 1.68 1.73 1.78

Staff interest in solving problems 1.85 1.85 1.73 1.73

Fast baggage handling 1.83 1.83 1.93 1.93

Fast check-in 1.73 1.72 2.03 2.03

Well informed of service details 1.75 1.75 1.89 1.92

Prompt service to customers 1.97 1.97 2.05 2.12

Willingness to help 1.96 1.98 1.96 1.98

Always respond to requests 2.15 2.12 2.15 2.17

Behaviour that instill confidence 1.78 1.78 1.78 1.78

Feel safe 1.52 1.52 1.64 1.67

Consistently courteous 1.65 1.62 1.61 1.65

Good knowledge answer questions 1.89 1.85 2.05 2.05

Individual attention 1.80 1.77 2.00 2.02

Convenient schedules 1.95 1.93 2.03 2.03

Personal care 2.10 2.08 2.18 2.18

Customers' interest at heart 1.85 1.83 1.85 1.83

Understand specific needs 1.99 1.95 2.02 2.10

Airline Expectations Airline Expectations

Sign. Sign.

Item Original Modified Dif. Original Modified Dif.

Modern looking aircraft 1.60 1.58 1.62 1.67

Visually appealing cabin 1.94 1.95 1.97 1.97

Neat appealing aircrew 1.59 1.56 1.59 1.63

Comfortable seat 1.80 1.78 1.88 1.91

On-time performance 1.60 1.57 1.63 1.67

Staff interest in solving problems 1.69 1.66 1.73 1.75

Fast baggage handling 1.77 1.73 1.83 1.88

Fast check-in 1.53 1.51 1.60 1.60

Well informed of service details 1.86 1.84 1.91 1.91

Prompt service to customers 1.67 1.63 1.67 1.73

Willingness to help 1.59 1.54 1.70 1.75

Always respond to requests 1.82 1.82 1.84 1.87

Behaviour that instill confidence 1.63 1.61 1.75 1.78

Feel safe 1.33 1.33 1.38 1.40

Consistently courteous 1.67 1.64 1.70 1.73

Good knowledge answer questions 1.80 1.78 1.89 1.92

Individual attention 1.99 1.96 2.01 2.05

Convenient schedules 1.89 1.86 1.91 1.91

Personal care 1.85 1.87 1.90 1.90

Customers' interest at heart 1.82 1.79 1.85 1.88

Understand specific needs 2.01 2.03 2.02 2.07

Airline Expectations Airline Expectations

Table 3.4: British Airways Pilot Survey Results