Societies ask for highly educated students and highly qualified educators. Education, training and culture of the youth is of the utmost significance for people, nations, economies and cultures . Needs posed by society on the quality in education and the chase of excellence are more than noticeable. Quality in education includes a multitude of issues such as satisfaction of both the internal clients (students/pre-service teachers, faculty and administration) as well as the external ones (parents, society). Tertiary education institutions ought to seek to fulfil students' expectations. According to ) and adjusting the service, in the case at hand, education to the student's expectations and the non-conformance to students' needs, the requirements posed by students/pre-service teachers, parents, educations and society, shows the way to the minimization of the quality of services.
In  it is argued that students withdrawal from a tertiary education institution when their expectations could not be fulfilled. In their work  the authors that service quality related to university image in strongly related to students satisfaction and loyalty. In their work  the authors proved that there is a significant relation between student satisfaction and service quality in tertiary education. In a line with the work of [10,19] argued that perceived service quality in related to satisfaction.
Many researchers work on students' expectations and perceptions in relation to University service quality [11,22,4,21]. For  undergraduate students' expectations and perceptions regarding University service is of a major importance.
In  the authors put embassies on the relation to perceived service quality with satisfaction. In the authors work  it is supported that the strong association between perceived service qualities with satisfaction. In their work , authors made a research centered on 145 undergraduate Australian university students' perceptions about university services.
Service quality in Tertiary Education can be evaluated in terms of the gaps between customers'/students'/pre-service teachers' expectations and perceptions , while 16] recommend that students/pre-service teachers ' assessment of service quality taken as a whole depends on the gaps between the expected and the perceived service. They have recognized five separate gaps between customers'/students/pre-service teachers' expectations and perceptions that we pay attention in this study. These five gaps are illustrated as follows (Figure 1).
• Gap 1: The knowledge gap, which refers to the difference between what customers/students/pre-service teachers ask for of a service and what management perceives that customers/students/pre-service teachers expect . In their work  the authors argued that management might have an erroneous perception of customers' tangible perception. In addition they pointed out that this gap has its roots in the lack of focus on customers/students/pre-service teachers ;
• Gap 2: The standards gap, which refers to the difference between what supervision, perceives that students/pre-service teachers or customers expect and the quality and specifications set for service delivery . In their work  the authors argued that the organization might not be able to translate customers' expectations into service provision. This gap relates with aspects of service design ;
• Gap 3: The delivery gap, referring to the difference between the quality provision set for a service release and the actual quality of service delivery. In their work  the authors argued that, with respect to services rendered; organizations do not offer high quality services. They suggested that the organization might be faced with, among others, employees and communication problems, the randomness of frontline employees and shortcomings relating to processes;
• Gap 4: The communications gap refers to the difference between the actual quality of service delivered and the quality of service described in the organization's external communications, such as advertising material and mass media advertising . In their work  the authors argued that customers', students'/pre-service teachers' in our case; expectation might be strongly influenced by the external relations of the organization. This gap relates to impracticable expectations shaped by the endorsement of positive perceptions that the organization is not capable of sustaining ;
• Gap 5: The service gap which summarizes all the other gaps and describes the difference between customers' expectations and their perceptions of the service they are given . Perceived quality of the service relates to difference between expectation and perception. A negative difference between customers'/students/pre-service teachers' perceptions and expectations shows a level of service quality below customers'/students/pre-service teachers' expectations .
Aim of the study
The rationale of present article is to examine the inter-relationships of key constructs related to pre-service teachers' satisfaction regarding ASPETE services. The endeavor of the document is to evaluate in ASPETE service quality in Greece by evaluating gaps between undergraduate students/pre-service teachers' expectations and perceptions as they relate to SERVQUAL dimensions with respect to students/pre-service teachers' loyalty. Thus this study will focus on Gap 5 between expected and perceived service. Consequently the current essay examines the connection or the gap between perceived and expected of service quality related to its dimensions named tangibility, reliability, assurance, responsiveness, empathy, and accessibility.
Education seeks for excellence and educators ought to be high qualified. Educators of high school technical education it is ought to share didactical and pedagogical skills. Thus the follow one year courses in School of Pedagogical & Technological Education named ASPETE. The establishment of the School of Pedagogical & Technological Education (ASPETE) in 2002 (article 4, Law 3027/2002 as amended by the Presidential Decree 101/2013 and article 29, Law 4186/2013) was paved by the vision and mission of SELETE, a Technical & Vocational Teacher Training Institute, founded in 1959 (Law 3971/1959) (retrieved from http://www.aspete.gr/index.php/en/).
The study uses Gap Analysis technique relating to SERVQUAL instrument in order to examine expectations and perceptions of Greek pre-service teachers that followed ASPETE studies.
The instrument employed to measure the satisfaction of Greek pre-service teachers with respect to quality is SEVQUAL [16,17]. According to  SEVQUAL has been the predominant method used to measure consumers' perceptions relating to service quality.
This tool consists of 25 items referring to five different attitude sub-scales, as follows:
• Tangibility: respondents' `positive or negative attitudes toward organization facilities and equipment, setting and advertising material about services (Tan1, Tan 2, Tan3, Tan 4, Tan5), (e.g., Tan1: ASPETE has up-to-date and well-maintained facilities and equipment). According to , tangibility strongly relates to the appearance of physical facilities, equipment, workforce, prospectuses and brochures. In  the authors claimed that the tangibility is strongly associated with modern looking equipment, physical facilities and personnel dressing code;
• Reliability: respondents' positive or negative attitudes toward services, timing, consistency of charges, staff professionalism and proficiency (items: Rel1, Rel2, Rel3, Rel4, Rel5, Rel6) (e.g., Rel1: Services should be provided at agreed times). According to [16,17], reliability strongly relates to the way customers are touched and service-related troubles and this factor is of a great significance in conventional service. In their work  the authors claimed that the reliability factor is the most important parameter for services;
• Responsiveness: respondents' positive or negative attitudes toward concerning prompt services and staff responsiveness (4 items: Res1, Res2, Res3, Res4) (Res1: e.g., Customers should be given punctual services). According to [16,17], responsiveness is strongly related to the timeliness of services;
• Assurance: respondents' positive or negative attitudes toward staff friendliness and courteousness, behavior and knowledge (4 items: Ass1, Ass2, Ass3 and Ass4) (e.g., Ass1: Friendly and courteous personnel). According to [16,17] assurance strongly relates to personnel knowledge and courtesy. Moreover, assurance is also closely associated with personnel professionalism to inspire trust and confidence. Additionally, according to , assurance relates, among others, to personnel politeness and friendliness, to knowledgeable personnel and to the provision of financial advice;
• Empathy: respondents' positive or negative attitudes toward service availability, customers' feedback, staff interest and empathy (4 items: Emp1, Emp2, Emp3 and Emp4) (e.g., Emp1: Obtain feedback from customers). Authors in  and authors in 17] named empathy as the compassionate and individual awareness the organization puts forward to its customers. In their work  authors asserted that the empathy is strongly related to both customers and personal attention, to understanding customers' requests and their best interests and to convenient working hours;
• Accessibility: respondents' positive or negative attitudes toward parking facilities and availability and organization position (3 items: Acc1, Acc2 and Acc3) (e.g., Acc1: There are adequate parking facilities).
Each item of the instrument used a 7-point Likert scale that ranged from 1 – Strongly Disagree to 7 – Strongly Agree.
Respondents' demographic profile
In total, a sample of 195 Greek undergraduate students/pre-service teachers from the ASPETE in Thessaloniki, Greece participated in the survey. Details of the respondents' demographic profile are presented in Table 1 as follows.
Before proceeding with the analysis, a reliability test was carried out to ensure that the data collected is reliable. The coefficient Cronbach's α is calculated to measure the reliability of the six dimensions, that is, Tangibility, Reliability, Responsiveness, Assurance, Empathy and Accessibility (Table 2).
Analysis of mean scores and service quality gap of perception and expectation of Greek undergraduate students/pre-service teachers
The following section presents the mean and the standard deviation of perception and expectations and the Service Gap of Greek undergraduate students/pre-service teachers on SERQUAL dimensions.
Gap analysis on tangibility
The following section presents the mean and the standard deviation of perception and expectations and the Service Gap of Greek pre-service teachers of ASPETE on Tangibility (Table 3).
From the results presented in Table 3 it can be observed that the mean expectation scores are greater than the mean perception scores in relation to all five attributes, fact that it can confirm that pre-service teachers are dissatisfied. However in terms of magnitudes of the gap scores, it was found the gap scores ranged from –0.09 to –0.40. Attribute Tab4 referring to whether Materials are associated with the service such as Brochures, pamphlets or statements are visually appealing has the highest mean both in terms of expectation and perception and the lowest in the dimension of Tangibility where attribute Tab2 refers to whether the psychical facilities is visually interesting both in terms of expectation and perception. It should also be noted that attribute 4, refers to whether ASPETE has up-to-date and well-maintained facilities and equipment, and has the highest negative sign.
Gap analysis on reliability
The following section presents the mean and the standard deviation of perception and expectations and the Service Gap of ASPETE's Students/pre-service teachers on Reliability (Table 4).
From the results presented in Table 4, it can be easily observed that the mean expectation scores are greater than the mean perception scores in relation to all four attributes. The outcomes illustrate that pre-service teachers are not satisfied as far as reliability is concerned. However, in terms of magnitudes of the gap scores, these ranged from –0.47 to –0.27. It must be said at this point, that attributes Rel8 and Rel0 have the highest negative signs and affirm that pre-service teachers are dissatisfied with both Rector and staff that are not have both professionalism and competence and the ASPETE' maintenance for accurate records for pre-service teachers.
Attribute Rel6 referring to whether ASPETE' services are reliable and carried out right the first time has the highest mean both in terms of expectation and perception.
Attribute Rel8 referring to whether the Rector and staff are both professional and competent has the lowest mean in terms of expectation and perception.
Gap analysis on responsiveness
The following section presents the mean and the standard deviation of perception and expectations and Service Gap of ASPETE pre-service teachers on Responsiveness (Table 5).
From the outcomes offered in Table 5 it can be fluently observed that the mean expectation scores are greater than the mean perception scores in relation to all four attributes, fact that it can again confirm students/pre-service teachers' discontent. Nonetheless in terms of the magnitudes of the gap scores, it was found that gap scores ranged from –0.47 to –0.30. It ought to be mentioned that attributes Res11 and Res14 have the highest negative sign and signify student dissatisfaction in relation to the offer of prompt services and to ASPETE personnel/staff always willingness to respond to students/pre-service teachers ' requests.
It should be noted that the highest mean in terms of expectations involve attributes Res14 and Res11 which shows that the students/pre-service teachers feel that these two are the attributes that matter the most to them. The highest mean in terms of expectation is observed in attribute res14, which relates to the ASPETE's personnel never being too busy to respond to students/pre-service teachers' requests. Attribute res11 relates to the statement states students/pre-service teachers should be given prompt services has the second higher mean in terms of expectation.
Attribute Res14 also has the highest mean score in terms of perception. Nevertheless, Attribute Res14, which refers to whether ASPETE's personnel never being too busy in relation to the responsiveness vis-a-vis their requests.
Nevertheless, Attribute Res13 which refers to whether personnel are Responsive scored the lowest mean in terms of perception.
Gap analysis on assurance
The following section presents the mean and the standard deviation of perception and expectations and Service Gap of ASPETE's Students/pre-service teachers on Assurance (Table 6).
From the results presented in Table 6 it is manifest that the mean expectation scores are greater than the mean perception scores in relation to all four attributes on assurance, fact that once again confirms students/pre-service teachers' dissatisfaction. Even so, in terms of magnitudes of the gap scores, it was found that the gap scores ranged from –0.76 to –0.37.
It is should be pointed out that attributes Ass16, Ass17 and Ass18 have the highest negative sign and thus were revealing of students/pre-service teachers' disappointment and dissatisfaction. Assurance attributes had the highest mean expectation scores and the highest mean perception scores in relation to all four attributes and to other constructs (Tangibility, Reliability, Responsiveness, Empathy and Accessibility). It can be noted that the highest negative sign of the gap, –1,500, is connected with Ass15, namely whether Rector and staff are friendly and courteous. Equally high was the negative gap, –0.76, of attribute Ass18 indicating that the behavior of personnel instills no confidante in students/pre-service teachers.
In line was also attribute Ass17 which manifested a large gap, –0.44, namely whether students/pre-service teachers are treated with dignity and respect.
In line was also attribute Ass16 which manifested a large gap, –0.44, namely whether Personnel (manager and staff) have the knowledge to answer students/pre-service teachers' questions.
It should be observed that the highest mean in terms of expectation involve attributes Ass18 and Ass17, which shows that the students/pre-service teachers feel that these two attributes are of a major importance to them. Attributes Ass18 and Ass17 demonstrate that students/pre-service teachers demanded from personnel to instill confidante in them and to be treated with dignity and respect. It can be noted that the highest mean in terms of perception involve attributes Ass17 and Ass15, 3.94 and 3.90, respectively.
Attribute Ass16 refers to whether personnel have sufficient knowledge to respond students/pre-service teachers' questions has the lowest mean both in terms of expectation and perception.
Overall, respondents expressed their greatest dissatisfaction with respect to personnel (rector and stuff) knowledge in order to answer students/pre-service teachers' questions. This resulted to the personnel (rector and stuff) insufficient knowledge in order to answer students/pre-service teachers' questions.
Gap analysis on empathy
The following section presents the mean and standard deviation of perception and expectations and Service Gap of ASPETE's Students/pre-service teachers on Empathy (Table 7).
From the results presented in Table 7 it can be observed without doubt that the mean expectation scores are greater than the mean perception scores with respect to all four attributes on Empathy, fact that added verifies pre-service teachers' dissatisfaction. Even so, in terms of magnitudes of the gap scores, it was found that the gap scores ranged from –0.69 to –0.54.
It is ought to be mention that attribute Emp21 has the second highest negative sign and signifies the discord by students/pre-service teachers for the unavailability of the Rector and staff to have students/pre-service teachers' best interest at heart.
It is ought to be mention that attribute Emp20 has the second highest negative sign and signifies the discord by students/pre-service teachers for the unavailability of the electronic services round the clock. Students/pre-service teachers stated that the opening and closing hours are extremely important for them.
Attribute Emp19, which refers to whether the personnel and the manager obtained feedback from students/pre-service teachers, had also a high negative sign.
Attribute Emp21, refers to whether it was thought that the manager and staff had the students/pre-service teachers' best interests at heart and it had the highest mean score in terms of both expectation.
Attribute Emp22 regards whether the manager and staff understood the specific needs of students/pre-service teachers and scored the lowest mean in terms of both expectation and perception.
Finally, attribute Emp22 which regards whether the manager and staff were capable of understanding their specific needs had the lowest mean score in terms of perception.
Gap analysis on accessibility
The following section presents the mean and the standard deviation of perceptions and expectations and the Service Gap of ASPETE students/pre-service teachers on Accessibility (Table 8).
From the results presented in Table 8 it can be observed that the mean expectation scores are greater than the mean perception scores in relation to all three attributes on Accessibility, fact that verifies the students/pre-service teachers' dissatisfaction. Even so, in terms of magnitudes of the gap scores, it was found that the gap scores ranged from –0.86 to –0.19.
It must be observed at that attribute Acc24 has the highest negative sign, –0.86, which stands for students/pre-service teachers' dissatisfaction with respect to the accessibility of their location.
Attribute Emp24 which relates to whether the ASPETE position is easily accessible exhibited the highest mean score in terms of perception and expectation.
Emp23 which relates to whether there were enough parking spaces exhibited the lowest mean score in terms of perception and expectation.
Ending, one could argue that Greek undergraduate students/pre-service teachers are not content by the quality of the ASPETE services. 195 pre-service teachers of our sample are seemed to be disappointed the ASPETE accessibility. Their perceptions declared that ASPETE position is not easily accessible, fact that it is true because the building is near THEAGENEIO Hospital and there is parking available in the area. 195 students/pre-service teachers, which they are our study sample, seemed to be very disappointed regarding behavior of personnel. Their perceptions are beyond their expectations. They claimed that personnel are not capable of instilling confidante in students/pre-service teachers. It is notable that our sample is expensing its disappointment for all attributes related to Empathy dimension. They expressed negative attitudes toward service availability, customers' feedback, staff interest and empathy. They stated that Rector and staff have not students/pre-service teachers 's best interest at heart, Opening hours of the ASPETE are not suitable and there is any 24-hour online service available, In addition the sample perceptions regarding Rector and staff feedback obtainment of from students/pre-service teachers and understanding their specific needs are beyond expectations. It is worth observing that there was a negative gap for all 25 attributes.
The research findings gave evidence on the need of understanding the current situation related to Quality Assurance Principles in Tertiary educational level. The institution ought to make greater efforts in order to meet students/pre-service teachers' needs and demands for excellence.