1. Introduction
Human life has been dependent on nature throughout history and human has had a peaceful relationship with the nature as an element of it. Therefore, technological developments, population growth, and the change of lifestyles, and the expansion of human needs paved the way for human domination in nature.
So, the irresponsible actions of human have directed the public attention to it worriedly and "human and environment" issue has been one of the global vital problems. Iran has also encountered various problems of environment because of growing population and being affected by the aforementioned developments. In fact, the human has been both the victim and cause of environment destruction as this period is called the period of environmental crisis. But environmental illiteracy further aggravates this crisis.
Thus, most countries of the world (included Iran) have provided the environmental education in formal and informal education and they have considered the environmental education in their syllabus (curriculum). In Iran, material design under the name of "human and the environment" has been done for this purpose.
The textbook "human and the environment" is a common subject for all the fields of study of senior high school that based on the general approach of the national curriculum of Islamic Republic of Iran placed in educational system of the country as an independent subject for the first time since 2019.
This textbook tries to provide the essential information at seven important areas of environmental education (including water, soil, energy, dirt, biodiversity and tourism), meanwhile it suggests wider ways for activating humans in preserving the environment. To achieve these goals, various texts, illustrations, graphs and activities (practices) have been used.
One of the most efficient ways to study the context and degree of achievement of educational goals is the analysis of textbooks' contents. This analysis helps to practical reviews of concepts, principles, attitudes, beliefs, and all components presented in the form of textbooks being compared and evaluated with curriculum purposes. The present study was done to analyze and evaluate the aims of textbook "human and the environment" and to measure the efficiency and effectiveness of the texts, illustrations and activities of this lesson. And the first question was:
Do the contents of textbook "human and environment" will actively engage the student and the reader with training and learning of environmental lessons?
2. The method of the Research
The methodological approach of this research is critical and its purpose is applied. The statistical population are visual and written contents of the textbook "human and the environment" of the senior high school (2023). The study of all contents of the textbook is corresponded to the statistical population and the sampling was avoided. The used method is content analysis. The tool of the study is William Romey's evaluation categorization checklist. William Romey by using the quantitative approach in content analysis has considered the objective and systematic description of the content and goes through the following steps:
1. Setting the goals
2. Sampling
3. Encoding
4. Classifying categories
5. Objective assessment of categories
This process leads the researcher to the question "Do the textbook and the intended content actively engage the students with the training and learning'?
By studying every lesson, paragraph or illustration, as the meaningful evidence and documents related to Romey' evaluation categories were seen, the related code in designed checklist was recorded and according to the frequencies, all contents of the book were analyzed. The content validity measurement of the tool was of a formal type and to measure the reliability of the tool, the concurrent reliability of multiple analysts were also used. Researchers as encoders encoded twenty percent of the content with time interval of 20 days twice and delivered to the analysts to measure the consensus between encoding. The consensus coefficient of analysts was determined 92 percent that indicates the reliability of the tool.
3. The Findings and Results
Active, inactive, neutral categories in texts, illustration, graphs, questions, and practices (exercises) of the textbook were considered as elements and units of analysis. In active categories, students are engaged in learning and teaching activities. But, in inactive categories, students aren’t literally involved in science activities. The engagement coefficient of each category of the contents of "human and environment" was achieved by William Romey Formula (by dividing the sum of active categories to inactive categories).
The engagement coefficient of the student with the content is a number which shows the activity rate of the content. The number may ranges from zero to infinite. However, according to Wiliam Romey, a textbook is active when its engagement coefficient is between 0.4 and 1.5. If engagement coefficient is less than 0.4, it indicates that the textbook presents only academic knowledge and the learners are expected to memorize it. The engagement coefficient over 1.5 also represents the textbook that every sentence, illustration or question makes the student to be active and analyze the content. Such books don’t provide assumptions or academic knowledge for the students and have anticipated plenty of activities.
The engagement coefficient of the text was 0.05 that was less than 0.4 and shows the frequency dominations of verbal sentences to conceptual sentences. This point also suggests that the book mainly focuses on academic knowledge and the learners are expected to memorize it.
The engagement coefficient for the illustrations and graphs of the study was 0.14 that is less than 0.4 and shows the images were mostly descriptive and didn’t make the learners active.
The frequency of active and inactive categories in questions and practices of the textbook "human and environment" was attained and inserted at table 5. The engagement coefficient of this index was 5.32 which is more than the range 0.5- 1.5. Such a coefficient indicates that the textbook makes the students to analyze and do some exercises and answer the questions. This requires the students to think about activities and do research.
The calculation of above three coefficients shows 1.83 in the following formula.
The engagement coefficient = (the sum of coefficients of text, illustrations and questions)
3
Table 1: Analysis of text, illustrations, and questions of the textbook "human and textbook of 11th grade based on William Romey Model
Chapter No Title of the chapter The sum of categories engagement coefficient
active inactive
text illustrations questions text illustrations questions text illustrations questions
1 Water, the source of life 9 3 33 73 21 7 0.12 0.14 4.71
2 Soil, the basis of life 2 - 18 47 12 14 0.04 0 1.25
3 Air, the essence of life
1 - 6 63 32 3 0.01 0 2
4 Energy, movement, life
12 - 24 81 33 3 0.14 0 8
5 Trash, the disaster of the environment
1 - 29 141 49 1 0.007 0 29
6 Biodiversity, a beautiful painting of creation
11 - 18 75 35 - 0.14 0 18
7 Environment, a responsible tourism platform
1 - 21 81 50 - 0.1 0 21
sum 33 3 149 566 212 28 0.05 0.14 5.32

The place of total engagement coefficient of the textbook is outside the range 0.4- 1.5.
4. Conclusion
The main purpose of this study was presenting a real and objective example of determining mental engagement coefficient of textbooks by using William Romey Model that teachers should consider the amount of attention to active and inactive categories in teaching process.
Undoubtedly, accumulation of facts and concepts of academic knowledge in the content of the text book turns it into memorization form that students aren’t interested in. The results of the research show the accumulation, especially in text and illustration of textbook "human and environment" of 11th grade in senior high school. Generally, inactive aspects of learning predominate in active aspects of learning in this book and active categories in the text and images of the book have less frequency.
Therefore, the future editions of the book should take into consideration the issues raised and to achieve lesson objectives (that is education of a generation who is aware, responsible, active and hopeful for the future), and suggests education (training) and culture of environment preservation. Since the adverse effects of humans on the environment and life threat have been revealed more than before, undoubtedly responsible actions in environmental crises will be accomplished by educating an informed generation. The awareness- raising is more effective at schools than any other time and the text book "human and the environment" with appropriate titles has a greater role in this field.