What difference does one course make? Assessing the impact of content-based instruction on students’ sustainability literacy

The study addresses the urgent global sustainability crisis and the role of Education for Sustainable Development (ESD) in equipping students with the knowledge, skills, and attitudes required to contribute to a sustainable future. Higher education institutions are seen as key actors in fostering sustainability literacy across disciplines. Composition studies, given their cross-disciplinary reach, are positioned to integrate sustainability into curricula through content-based instruction (CBI). Despite interest in ESD, there is a gap in empirical research on how curriculum design, particularly CBI, impacts students’ sustainability literacy. The purpose of this study is to evaluate whether a structured, sustainability-focused CBI module in a first-year writing course improves students’ sustainability literacy (knowledge, skills, attitudes, and familiarity with topics and concepts) and influences how students identify sustainability problems and solutions in Kuwait. The research questions were: (1) Did the content-based instruction have any significant effect on the participants' sustainability literacy levels? (2) Are there any differences between the control and experimental groups' essays in terms of students' perceptions of sustainability challenges and their solutions in Kuwait? The study adopts a case study approach to explore these questions in a real institutional context.

The background reviews three domains: (1) Sustainability: Historically rooted prior to modern environmental science, sustainability now encompasses three pillars—environmental, economic, and social. Since the Brundtland Report (1987), sustainability has been defined around intergenerational equity, with education central to enabling informed decision-making and pro-environmental behaviors. (2) Sustainability literacy: Tools such as SULITEST and institutional frameworks like AASHE’s STARS have emerged to assess and promote sustainability literacy. Accurate, reliable measures are vital to improve sustainability education and outcomes. (3) Sustainability in Kuwait: Kuwait’s economy relies heavily on oil (over 90% of export earnings), generating environmental challenges (air pollution, water scarcity, waste management) and high per-capita consumption of water and energy. While national initiatives (Vision 2035; KNDP) target SDGs, Kuwait ranks 101st/163 in SDG performance (score 64.53), with noted gaps in public awareness and policy implementation. Studies highlight inadequate responses to pollution, limited awareness of sustainable construction and waste management, and the need for greater sustainability literacy. The review also covers CBI as an instructional approach that integrates content and language learning, with evidence of improved academic outcomes and content knowledge. However, few empirical studies assess CBI’s impact on sustainability literacy, indicating a research gap this study seeks to address.

Design: True experimental design with random assignment to control and experimental groups based on course section enrollment, using a mixed-method sequential explanatory approach (quantitative followed by qualitative). Duration: 6 weeks of CBI intervention during Fall 2022. Participants: 221 first-year composition students at a private university in Kuwait (instruction in English); 100 in the experimental group (CBI on sustainability) and 121 in the control group (regular curriculum). Demographics varied by gender, high school type, college, GPA, and prior exposure to the term sustainability. Ethics: IRB approval obtained (IRB-278674/2023-24); informed consent collected. Quantitative data collection: Adapted Sustainability Literacy Assessment (University of Wisconsin–Oshkosh, STARS framework, 2018), comprising: (a) 5 multiple-choice knowledge questions; (b) five-point Likert scales for self-reported skills, attitudes, and familiarity with sustainability topics and concepts. Reliability (Cronbach’s alpha): Skills (pre 0.814; post 0.893), Attitudes (pre 0.715; post 0.806), Topics & Concepts (pre 0.920; post 0.950). Administration: Pretest before instruction; posttest at semester end. Quantitative analysis: SPSS v25; descriptive statistics; chi-square for group homogeneity; assessment of normality (Q–Q plots; skewness/kurtosis ±3); independent t tests for between-group comparisons; dependent t tests for within-group comparisons; one-way ANOVA for >2 groups where applicable. Qualitative data collection: At semester end, students wrote a supervised, in-class essay (50 minutes, computer-based) identifying Kuwait’s major sustainability challenge(s) and proposing solutions. Essays collected: experimental 65, control 67; low-word-count essays removed (5 experimental; 7 control), leaving 120 essays (60 per group) for analysis. Qualitative analysis: MAXQDA 2022 used for content analysis. Procedures included data preparation, inductive and deductive coding, theme development, and interpretation. Quantitative content analysis of word frequencies conducted via MAXDictio. Dictionary-based analysis used AASHE’s Suggested Keywords for Sustainability Course and Research Inventories to count sustainability-related terms.

- Knowledge (5-item test): Experimental group increased correct answers on all items from pretest to posttest; control group showed mixed changes. Between-group independent t test showed no significant difference at pretest but a significant difference at posttest favoring the experimental group (Table 4: posttest p=0.004; experimental mean 1.79±1.33 vs control 1.22±1.17). - Skills, Attitudes, Topics & Concepts (Likert scales): No significant pretest differences; significant posttest improvements favoring the experimental group (Table 5): Skills p<0.001 (experimental 3.74±0.75 vs control 3.17±0.93), Attitudes p=0.037 (3.79±0.67 vs 3.56±0.80), Topics & Concepts p=0.001 (3.55±0.71 vs 3.11±1.01). - Essay content analysis—problems identified: Total codes: control 94 vs experimental 137. Environmental problems most frequent in both groups (pollution/littering; climate change/extreme heat; biodiversity loss; resource scarcity). Experimental group identified more social sustainability issues (e.g., corruption, gender inequality, education quality), which were largely absent or rare in control essays. - Essay content analysis—solutions proposed: Total codes: control 104 vs experimental 137. Both groups proposed similar environmental solutions (e.g., clean energy, awareness, fines/penalties, conservation/recycling, public transport, tree planting, waste management, emissions laws, relocating industry). Experimental-only solutions included Kuwaitization, creating jobs, improving education quality, reducing inequality/discrimination, and reducing traffic accidents. - Sustainability keyword usage (dictionary-based): Despite a slightly lower total word count, the experimental group used more sustainability-related keywords (experimental 122 keywords across 27,751 words; control 97 across 28,303 words). Overall, the CBI intervention significantly improved students’ sustainability literacy and enriched the breadth and depth of sustainability concepts in their writing.

The findings directly address the research questions. RQ1: CBI significantly enhanced students’ sustainability literacy as seen in superior posttest knowledge scores and higher self-reported skills, attitudes, and familiarity with sustainability topics and concepts in the experimental group. RQ2: Essays from the experimental group identified a broader range of sustainability challenges and solutions, particularly in the social pillar (e.g., corruption, gender inequality, education quality), suggesting that CBI not only deepened conceptual familiarity but also broadened students’ perspectives beyond the commonly emphasized environmental dimension. These results align with literature acknowledging CBI’s effectiveness in improving content learning and language outcomes. They also resonate with prior observations that students tend to focus on environmental aspects of sustainability; however, the CBI module appears to have expanded students’ attention to social and economic dimensions relevant to Kuwait’s context. Increased use of sustainability keywords despite similar essay lengths indicates richer sustainability discourse among CBI participants. Collectively, the quantitative and qualitative findings suggest that targeted, sustainability-focused CBI can effectively cultivate comprehensive sustainability literacy within a composition course.

This study demonstrates that a six-week sustainability-focused CBI module integrated into a first-year composition course significantly improves students’ sustainability literacy across knowledge, skills, attitudes, and familiarity with key concepts. The approach also enhances students’ ability to recognize and articulate sustainability challenges and propose solutions, notably expanding their engagement with social sustainability issues relevant to Kuwait. Contributions include: (1) empirical evidence supporting the efficacy of integrating sustainability into language education via CBI in an ESL context; (2) highlighting interdisciplinary potential to mainstream sustainability education across higher education curricula. Recommendations include institutional support for faculty development, cross-departmental collaboration, and embedding sustainability themes across programs to prepare graduates to address SDGs. Future research should examine longer interventions, larger and more diverse samples, multi-instructor implementations, and longitudinal follow-up to assess retention and behavioral outcomes.

- Short intervention duration (6 weeks). - Single-site case study with a relatively small, specific student population; one instructor designed and delivered the CBI materials, limiting generalizability. - Post-intervention assessment conducted at semester end; no longitudinal data on retention or longer-term behavior change. - Uneven posttest participation due to absences/withdrawals may affect comparability across time points.