Revista Română de Statistică Trim III/2012- Supliment 25 Methodological Rigors in the Statistical Research on Urban Household Waste Senior Lecturer Gheorghe SĂVOIU, Ph.D. Professor Ion IORGA SIMĂN, Ph.D. Senior Lecturer Constantin MANEA, Ph.D. University of Pitesti Lecturer Mladen ČUDANOV, Ph.D. University of Belgrade Abstract. This article describes the conditions imposed, the constraints and the solutions that are specific to statistical research in the broad field of ecology, materialized within the limited range of urban waste. Exhaustive investigation and analysis of the general and local, as well as the comprehensive population data, the sampling, the concrete sample-taking, formulating the objectives and drawing up the questionnaire are presented. A final remark in the present paper underlines the specificity of an ecology-related statistical survey as an useful alternative for those who want to conduct researches in contemporary ecological environment, and especially in the area of household waste. Key words: random sampling, calculation of sample size, sampling, homogeneous variables, descriptive statistics. 1.Introduction The Earth is a living organism, but accidental or deliberate human interference with the environment systematically causes serious changes so that it is possible to transform the Earth into a lifeless planet, over a very short time. The environment is affected by quite numerous factors, one of the most damaging being waste, especially that collected and stored improperly. Some waste contains glass, metals, plastics, and other similar materials that should be separated for recycling. Local authorities can burn the rest, producing useful heat, or use it to fill the abandoned land of former mines or quarries. The concept of household waste (waste usually resulting from the housework, waste from shops, hotels, canteens, catering establishments, schools and other public institutions where the specific activity or the presence of people can produce residues with a composition similar to household waste) has led to the emergence and development of an industry with a remarkable upward trend. 2. Some statistical information about household waste The structure of the Romanian household waste bin is very different if compared to that of France or the U.S., as shown in the table below.