Research on the Evaluation System of Vocational College Teachers' Teaching Ability in the Digital Economy Era

. The era of digital economy promotes the transformation of enterprises and puts forward new requirements for the development of talent ability and higher requirements for the teaching quality of vocational colleges. A scientific and reasonable evaluation system can evaluate the teaching ability of vocational college teachers, accurately locate and solve the problems existing in teaching links, so as to achieve a new leap in the level of vocational college teachers and better meet the needs of the times.Based on the excellent practice achievements of American universities and the iceberg theory model, this paper takes Shanghai Vocational College as an example, and makes a statistical analysis of the data obtained from 208 questionnaires by using analytic hierarchy process, so as to establish a more refined, scientific and timely evaluation system and evaluation rules for teachers' teaching ability in vocational colleges. The evaluation system takes "students" as the evaluation subject, "teachers" as the evaluation basis, and "evaluation questionnaire" as the evaluation form, including 2 first-level indicators, 5 second-level indicators and 24 third-level indicators.


Preface
The rapid development of the digital economy has promoted the transformation and upgrading of global economic and social development [1].The arrival of the digital economy era promotes the transformation and development of enterprises, puting forward higher requirements for the post competence of employees, and then affecting the development of teachers' teaching ability in vocational colleges.In addition, during the COVID-19 epidemic, the mode of "Internet+Education" showed a spurt development in China, which accelerated the pace of the reform of traditional teaching mode in China vocational colleges [2]. In the post-epidemic era, the sudden changes in application scale, popularization speed, technology update and other situational factors put forward new requirements for the teaching development of vocational colleges. As the main body of vocational education, full-time teachers in vocational colleges are the main factors that affect the development of vocational education. The emergence of new background and elements requires vocational college teachers to change their concepts, updating their teaching ability and adapting to the new development [3].In February 2021, at the press conference of the Ministry of Education, Wu Yan, director of higher education, pointed out that in the future, colleges and universities would vigorously promote the establishment and improvement of an evaluation system that adapted to online teaching and online+offline mixed teaching. It can be seen that it is urgent to establish an evaluation system for teachers' teaching ability of vocational colleges in the era of digital economy [4].Therefore, this paper studies the teaching ability of teachers in vocational colleges by using analytic hierarchy process and questionnaire survey, and constructs an evaluation system for the teaching ability of teachers in vocational colleges in the digital economy era, with a view to accurately judging the teaching work of teachers in vocational colleges and truly reflecting the actual teaching level of teachers, so as to better reflect and improve teaching, continuously improving the teaching quality of schools, and then cultivating more talents suitable for the development needs of the times, society and enterprises [5].

Literature research
Developed countries such as Europe and America began to evaluate teachers' teaching ability as early as the mid-1920s [6]. China began to evaluate teachers' teaching ability in 1960s, mainly evaluating teachers' professional level and academic ability, and the results served as the basis for teachers' promotion, employment and performance-based salary [7].At present, most vocational colleges in China are still using traditional methods such as students, peer teachers, department leaders and teaching supervisors to evaluate teachers' teaching ability. This traditional evaluation system can basically reflect the different characteristics and abilities of teachers, but it still has some defects [8].The traditional teaching evaluation system focuses on the assessment of teachers' classroom skills, but ignores the assessment of teachers' professional ethics, career loyalty, teaching discipline and other hidden basic qualities. In addition, the traditional teaching evaluation system of teachers in vocational colleges still has some disadvantages, such as lack of quantification and refinement [9].In the era of digital economy, the development of educational technology, the characteristics of digital aborigines of students and the trend of teaching reform in vocational colleges make digital information technology become the focus of current and future teaching research development. Horizon Report of New Media Alliance: 2017 Higher Education Edition clearly pointed out that the best practical experience of online learning and faceto-face learning would become the "new normal" of future education [10].Therefore, based on the comprehensive influence of digital economy on the development of society, enterprises and education, it is very positive social practical value and significance to establish a more refined, scientific and effective teaching evaluation system for vocational college teachers that adapts to the development of the times.

Construction of evaluation system
Based on the existing literature, we can find that there are significant similarities when most universities at home and abroad set up teaching ability evaluation systems.
So based on the teaching ability evaluation system of American colleges and universities, this paper takes 10 vocational colleges such as Shanghai Urban Construction Vocational College as an example,as to obtain relevant data and information through questionnaire survey, and construct a teaching evaluation system for vocational college teachers adapting to the digital economy era.

3.1Determination of the hierarchy of specific indicators
In order to make the evaluation index system of vocational college teachers' teaching ability in the digital economy era meet the requirements of concreteness, refinement, scientificity and feasibility, this paper strictly follows the principles of systematicness, typicality, dynamics, scientificity and operability in the research process to set up questionnaires and construct indicators.
According to the iceberg theory model of American scholars Lyle M. Spencer, Jr. & Signe M. Spencer [11], the teaching ability of vocational college teachers in the digital economy era is divided into explicit partial quality with benchmark characteristics and implicit partial quality with discriminating characteristics. Among them, the basic skills of explicit quality teaching are in the upper part of the iceberg, and the basic literacy of implicit quality teachers is in the lower part of the iceberg. On this basis, the first-level indicators of the system are further refined at the second and third levels, so as to reflect the teaching ability of vocational college teachers in the digital economy era more scientifically and comprehensively [12].
In the digital economy era, the evaluation index of teachers' teaching ability in vocational colleges is compared with the iceberg model, as shown in Table 1. The iceberg model of teachers' teaching evaluation index in vocational colleges includes the dominant factors mainly refering to teaching technology, teaching methods, teaching content, teaching language expression and so on; The hidden factors are mainly the internal factors such as teachers' quality, self-awareness and values. These factors cannot be directly observed and measured, but they determine the development potential and state of teachers.

Vocational college teachers' teaching ability evaluation index system
Based on the questionnaire survey of experts, scholars, teaching supervisors, peer teachers, leaders of competent departments and workers in colleges and universities in 10 vocational colleges in Shanghai, an evaluation system of teachers' teaching ability in vocational colleges is established, including two first-class indicators such as basic teaching ability, five second-class indicators such as teaching methods and 24 third-class indicators. After processed the data of the expert scoring table by AHP, the weights of each index of the evaluation system are obtained, and the specific index system is shown in Table 2.  Table 2 includes three-level indicators of teachers' teaching ability in vocational colleges, including two first-level indicators, namely basic teaching skills (0.56) and basic teaching literacy (0.44), and five second-level indicators, including teaching methods and tools (0.25), teaching content (0.16), teaching effect (0.15), teaching imparting (0.27) and professional ethics (0.27). There are 24 three-level indicators, and each three-level indicator is also matched its own weight.

Evaluation form
Based on the evaluation system of teachers' teaching ability in Shanghai Vocational College, a questionnaire is designed to evaluate teachers' teaching ability, and the evaluation subjects are organized to grade the completion of teachers' indicators, and then the grading results are graded according to the scoring standards [13], and then the scoring results are summarized according to the scoring standards, and finally the evaluation results of teachers' teaching ability are obtained. The questionnaire for teaching evaluation is based on 24 three-level indicators of the evaluation system of teachers' teaching ability in vocational colleges, and there are six different grades of A,B,C, D, E, F. The evaluation subject should check the grades of teachers' scoring items with reference to the scoring standards. The rating scales corresponding to the six different grades are: very consistent with the description (10 points), close to the description (8 points), not far from the description (6 points), far from the description (4 points), far from the description (2 points) and uncertain (0 point).

Evaluation scoring system
The evaluation and scoring system of teaching ability in vocational colleges in the era of digital economy includes four parts: three-level index score, two-level index score, one-level index score and comprehensive score.
The scores of the three-level indicators are expressed by i H , which is determined by the scoring situation of the teaching evaluation questionnaire. The scoring grades A, B, C, D, E and F are 10, 8, 6, 4, 2 and 0 respectively, and the scoring scores of the three-level indicators and the corresponding weight coefficients are recorded. The calculation formula of the three-level index score is: The second-level index score includes five aspects: teaching methods, tools, teaching content, teaching effect, teaching imparting and professional ethics score, The evaluation system of teachers' teaching ability in vocational colleges in the era of digital economy established by questionnaire survey and analytic hierarchy process in this paper is systematic, scientific and timely. The three-level quantitative indicators of teachers' teaching in vocational colleges are detailed and quantitative, and the scientific and reasonable weight makes it more operational and practical in implementation. Specific performance in the following three aspects:

The evaluation index more detailed
The traditional teaching evaluation index system of teachers in vocational colleges mostly has only two levels of evaluation indicators, and the logical relationship between the indicators is not strong. At the same time, there were too many qualitative indicators, too few quantitative indicators, and lacked clarity in evaluation standards. Based on the iceberg model theory, this paper establishes a three-level index system by questionnaire survey and analytic hierarchy process, and sets scientific weights for each level index and each specific index combined with data, making the evaluation index system more refined and rational. At the same time, the indicator system includes both explicit and implicit indicators of teachers' teaching ability, which not only pay attention to teachers' current ability status and teaching effect, but also pay attention to teachers' future development potential. Therefore, this evaluation index system can evaluate the teaching ability of teachers in vocational colleges more comprehensively and systematically.

Index weight distribution more scientific and reasonable
In the course of this research, by soliciting opinions and opinions from experts, scholars, teachers and other relevant people at different levels, this paper invites industry experts to grade, improve and optimize the questionnaire setting, and uses analytic hierarchy process to make statistics, calculation and analysis on the data obtained from the questionnaire survey, and finally determines a reasonable and scientific index weight distribution. The traditional evaluation system of teachers' teaching ability in vocational colleges paid little attention to teachers' potential teaching ability and literacy, and lacked evaluation and weight distribution of teachers' potential teaching ability. From the perspective of development, this paper studies the establishment of indicators of teachers' potential and explicit teaching ability in vocational colleges, with scientific weight, This makes this indicator system more scientific and reasonable.

Teaching evaluation more timely and applicable
Based on the background of the development of digital economy, this paper investigates the teachers of ten typical vocational colleges with different development strengths in Shanghai. Experts, scholars and industry authorities score the teachers' teaching abilities in six different grades, and then summarizes the scores according to the scoring standards of the evaluation system, and finally gets a systematic quantitative index system of the three-level teachers' teaching ability, which embodies strong timeliness and applicability.

5.Conclusions
Based on the background of digital economy's transformation and development of society and enterprises, this paper focuses on the internal needs of vocational college personnel training to serve the development of society and enterprises, studies the teaching ability of vocational college teachers and establishes a quantitative index system. Through literature research, questionnaire survey and analytic hierarchy process, this paper establishes a teaching evaluation system for teachers in vocational colleges, which includes two primary indicators, five secondary indicators and 24 tertiary quantitative indicators. The research results are timely, scientific and operable.