Environmental and Social Impact Statement (ESIS) for a proposed development is vital in guiding decision makers arrive at an informed decision. Many studies have analysed ESIS quality using qualitative methods with limited statistical analysis. In this paper, we present findings of a statistical analysis of qualitative data of ESIS using Somers’ delta test (Somers’d). we report on how public participation and analysis of alternatives influence the quality of ESIS. Results show that there is a strong and positive correlation between the quality of ESIS and public participation and also between the quality of ESIS and the analysis of alternatives, which is statistically significant, p < 0.0005, Somers’ d = 0.676 and p <0.0005, Somers’ d = 0.682, respectively.
alternatives analysis, environmental and social impact statements, public participation, Somers’ delta test
 Dendena, B. & Corsi, S., Environmental and Social Impact Assessment: a further step towards an integrated assessment process. Journal of Cleaner Production, 108, pp. 965–977.
 Muse, G.S., Environmental and social impact assessment for modular power plants project in Menengai, Nakuru County, Kenya: impact Identification, evaluation and risk analysis. Journal of Environmental Pollution Research, 4(2), pp. 1–12, 2016.
 K amijo, T. & Huang, G., Improving the quality of environmental impacts assessment reports: effectiveness of alternatives analysis and public involvement in JICA supported projects. Impact Assessment and Project Appraisal, 34(2), pp. 143–151, 2016.
 Aung, T.S., Evaluation of the environmental impact assessment system and implementation in Myanmar: its significance in oil and gas industry. Environmental Impact Assessment Review, 66, pp. 24–32, 2017.
 Arts, J., Fischer, T.B., Runhaar, H. & Jha, T.U., Environmental Governance: reflecting on 25 years of EIA practice in the Netherlands and the UK. Journal of Environmental Assessment Policy and Management, 14(4), pp. 1–40, 2012.
 Rowe, G. & Frewer, L.J., Public participation methods: a framework for evaluation. Science, Technology, and Human Values, 25(1), pp. 3–29, 2020.
 André, P., Enserink, B., Connor, D. & Croal, P., Public Participation International Best Practice Principles. International Association for Impact Assessment. Special Publication Series No. 4, Fargo, ND, 2006.
 B arasa, P.J., Public participation in the implementation of 280 MW power project at Olkaria in Naivasha Sub-County, Nakuru County, Kenya. Proceedings of the World Geothermal Congress; 19–25 April; Melbourne, Australia, 2015. Available at http://agid.theargeo.org/reports/Kenya/Public%20Participation%20in%20the%20Implementation%20of%20280MW%20Geothermal%20Power%20Projects%20-%20.
 Omenge, P.M., Eshiamwata, G.W., Makindi, S.M. & Obwoyere, G.O., Public participation in environmental impact assessment (EIA) and its substantive contribution in environmental risk management: insights from EIA practitioners and other stakeholders in Kenya’s renewable energy projects. WIT Transactions on Ecology and the Environment, 237, pp. 133–144, 2019. DOI: 10.2495/ESUS190121.
 Glasson, J., Therivel, R. & Chadwick, A., Introduction to Environmental Impact Assessment, 4th ed., Milton Park, Abingdon Oxon, 2012.
 W orld Bank, Environmental Impact Assessment Regulations and Strategic Environmental Assessment Requirements: Practices and Lessons Learned in East and Southeast Asia. Safeguard Dissemination Note 2. World Bank: Washington, DC, 2006.
 Stookes, P., Getting to the real EIA. Journal for Environmental Law, 15(2): pp. 141–151, 2003.
 Annandale, D. & Taplin, R., Is environmental impact assessment regulation a ‘burden’to private firms? Environmental Impact Assessment Review, 23(3), pp. 383–397, 2003.
 Veronez, F.A. & Montaño, M., Towards a systematic use of quality review packages. 38th Annual Conference of the International Association for Impact Assessment; 16–19, 2018. Durban, South Africa. Available at https://conferences.iaia.org/2018/finalpapers/Montano,%20Marcelo%20%20Towards%20the%20systematic%20use%20of%20quality%20review%20packs.pdf.
 Ortolano, P. & Shepherd, A., Environmental impact assessment: challenges and opportunities. Impact Assessment, 13(1), pp. 3–30, 1995.
 Fedra, K., Expert Systems for Environmental Screening. International Institute for Applied Systems Analysis: Laxenburg, Austria, 1991. Available at http://pure.iiasa.ac.at/id/eprint/3481/1/RR-91-019.pdf.
 Glasson, J., Therivel, R. & Chadwick, A., Introduction to Environmental Impact Assessment. UCL Press: London, UK, 1999.
 Steinemann, A., Improving alternatives for environmental impact assessment. Environmental Impact Assessment Review, 21(1), pp. 3–21, 2001.
 Leopold, L.B., Clarke, F.E., Hanshaw, B.B. & Balsley, J.R., A Procedure for Evaluating Environmental Impact. U.S. Geological Survey: Washington, USA, Circular 645, 1971.
 O’Faircheallaigh, C., Public participation and environmental impact assessment: Purposes, implications, and lessons for public policy making. Environmental Impact Assessment Review, 30(1), pp. 19–27, 2010.
 Innes, J.E. & Booher, D.E., Reframing public participation: strategies for the 21st century. Planning Theory and Practice, 5(4), pp. 419–436, 2004.
 Stewart, J.M. & Sinclair, A.J., Meaningful public participation in environmental assessment: Perspectives from Canadian participants, proponents, and government. Journal of Environmental Assessment Policy and Management, 9(2), 161–183, 2007.
 W ang,Y., Cao, H., Yuan, Y. & Zhang, R., Empowerment through emotional connection and capacity building: public participation through environmental non-organizations. Environmental Impact Assessment Review, 80, pp. 1–9, 2020.
 Mora, B.J.C., Sibaja, B.J.P., Piedra, M.G. & Molina, L.O.M., Environmental Impact Assessment of 17 construction projects in various university campuses. International Journal of Environmental Impacts, 1(4), pp. 433–449, 2018.
 Peterson, K., Quality of environmental impact statements and variability of scrutiny by reviewers. Environmental Impact Assessment Review, 30, pp. 169–176, 2010.
 Omenge, P.M., Obwoyere, G.O., Eshiamwata, G.W., Makindi, S.M. & Nathwani, J., Environmental and Social Impact Assessment procedural steps that underpin conflict identification: Reference to renewable energy resource development in Kenya. International Journal of Energy Production and Management, 5(2), pp. 157–174, 2020. DOI: 10.2495/EQ-V5-N2-157-174.
 Jiricka-Pürrer, A., Bösch, M. & Pröbstl-Haider, U., Desired but neglected: investigating the consideration of alternatives in Austrian EIA and SEA practice. Sustainability, 10(10), pp. 3680, 1–21, 2018.
 CEQ (Council on Environmental Quality), Regulations for Implementing the procedural provisions of the National Environmental Policy Act, 1996.
 B enson, J.F., What is the alternative? Impact assessment tools and sustainable planning. Impact Assessment and Project Appraisal, 21(4), pp. 261–280, 2003.
 Therivel, R. & Partidario, M.R., The Practice of Strategic Environmental Assessment, Earthscan Publications Ltd: London, UK, 1996.
 Mwenda, A., Bregt, K., Ligtenberg, A. & Kibutu, N., Trends in consultation and public participation within environmental impact assessment in Kenya. Impact Assessment Project Appraisal, 30(2), pp. 130–135, 2012.
 Measham, T.G. & Schandl, H., How to enhance government capacity to deliver benefits from resource extraction including through social impact assessment and environmental impact assessment? A conference paper presented at the Pacific Symposium on Managing Extractive Industries in Pacific Island States to Improve Human Development, Nadi, Fiji, 2013. Available https://www.researchgate.net/publication/248381848.
 Republic of Kenya, The Environmental Management and Coordination (Air Quality) Regulation. Legal Notice No. 34, Government Printer: Nairobi, Kenya, 2014.
 Republic of Kenya, The Environmental Management and Coordination (Noise and Excessive Vibration Control) Regulation. Legal Notice No. 61. Government Printer: Nairobi, Kenya, 2009.
 Republic of Kenya, Environmental Management and Coordination (Water Quality) Regulations. Legal Notice No. 120. Government Printer: Nairobi, Kenya, 2006.
 Republic of Kenya, Environmental Management & Coordination (Waste Management) Regulations. Legal Notice No. 121. Government Printer: Nairobi, Kenya, 2006.
 Mwenda, A. & Kibutu, T.N., Implications of the New Constitution on Environmental Management in Kenya. Law, Environment and Development Journal, 8(1), pp. 76-88, 2012.
 Republic of Kenya, The Constitution of Kenya. Government Printer: Nairobi, Kenya, 2010.
 Barasa, P.J., Integration of environmental assessment in geothermal resource development process: A case study of Olkaria geothermal fields. Proceedings of the 6th African Rift Geothermal Conference, 2–4 Nov, Addis Ababa, Ethiopia, 2016. Available at http://theargeo.org/fullpapers/INTEGRATION%20OF%20ENVIRONMENTAL%20ASSESSMENT%20IN%20GEOTHERMAL%20%20RESOURCE%20DEVELOPMENT%20PROCESS.pdf.
 Republic of Kenya, Environmental Management and Coordination (Conservation of Biological Diversity and Resources, Access to Genetic Resources and Benefit Sharing) Regulations. Legal Notice No. 160, Government Printer: Nairobi, 2006.
 Republic of Kenya, The Environmental Management and Coordination Act No. 8 of 1999: Amendment of the Second Schedule. Legal Notice No. 31, Government Printer: Nairobi, Kenya, 2019.
 Republic of Kenya, National Energy Policy, Ministry of Energy, Government Printer: Nairobi, Kenya, 2018.
 Ngugi, P.K., Financing the Kenya geothermal vision. Proceedings of the Geothermal Development and Geothermal Wells; 11–17 March, UNU-GTP and LaGeo, Santa Tecla, El Salvador, 2012. Available at http://agid.theargeo.org/reports/Kenya/FINANCING%20THE%20KENYA%20GEOTHERMAL%20VISION.pdf.
 Mwangi, M.N., Phases of geothermal development in Kenya. Proceedings of the Decision Makers on Geothermal Projects and Management, 14–18 Nov, UNU-GTP, KengGen, Naivasha, Kenya, 2005. Available at https://orkustofnun.is/gogn/unu-gtp-sc/UNU-GTP-SC-01-06.pdf.
 Mwangi, M.N., Environmental and socio-economic issues of geothermal development in Kenya. Proceedings of the Decision Makers on Geothermal Projects in Central America, 26 Nov–2 Dec, UNU-GTP, LaGeo: San Salvador, El Salvador, 2006. Available at https://orkustofnun.is/gogn/unu-gtp-sc/UNU-GTP-SC-02-05.pdf.
 B aba, A., Geothermal Environmental Impact Assessment with Special Reference to the Tuzla, Geothermal Area, Canakkale, Turkey. The United Nations University Geothermal Training Programme Reykjavík, Iceland, 2003. Available at https://orkustofnun.is/gogn/unu-gtp-report/UNU-GTP-2003-05.pdf.
 K ubo, B.M., Environmental management at Olkaria Geothermal Project, Kenya. Proceedings of the International Geothermal Conference, 1–5 September, Reykjavík, 2003. Available at https://orkustofnun.is/gogn/unu-gtp-25-ann/UNU-GTP-IGC-2003-13.pdf.
 K rejcie R.V, Morgan D.W., Determining sample size for research activities. Educational and Psychological Measurement, 30, 607–610, 1970.
 Isaac S. & Micheal W.B., Handbook in Research and Evaluation. In Hill R. 1998. “What Sample Size is ‘Enough’ in Internet Survey Research”? Interpersonal Computing and Technology: An Electronic Journal for the 21st Century, 1995.
 Lee, N., Colley, R., Bonde, J. & Simpson, J., Reviewing the Quality of Environmental Assessments and Environmental Appraisals. University of Manchester: Manchester, UK, 1999.
 K umar, R., Research Methodology: A Step-by-Step Guide for Beginners. SAGE Publications Ltd: London, EC1Y 1SP, 2011.
 Somers, R.H., A new asymmetric measure of association for ordinal variables. American Sociological Review, 27: pp. 799–811, 1962.
 Newson, R., Confidence intervals for rank statistics: Somers’ D and extensions. The Stata Journal, 6(3), pp. 309–334, 2006.
 Liebetrau, A.M., Measures of Association. Sage: Thousand Oaks, CA, 1983.
 Ulibarri, N., Scott, T.A. & Perez-Figueroa, O., How does stakeholder involvement affect environmental impact assessment? Environmental Impact Assessment Review, 79, pp. 1–11, 2019.