id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
bcpe-778	Zhou, Jiayi	Progress and Implications of Experimental Research in the Field of International Environmental Policy	2022	11	.pdf	application/pdf	5058	231	44	Data Analysis The results of the data analysis can be divided into two parts: the first part is a description of the overall situation of experimental research in the field of environmental policy, including the publication of the literature over the years and the geographical distribution characteristics of the studies; the second part is an analysis of the specific studies of the three types of experimental methods, including the themes of the studies, the use of experimental designs, the types of samples and recruitment, and the selection of dependent variables, etc. 3.1 Overview of the General Situation First, this paper analyses the number of publications and the distribution of the three types of experimental studies in each journal over time, as shown in Figures 2, 3 and 4. Next, studies on laboratory experiments, survey experiments and field experiments were selected, and studies on natural experiments, quasi- experiments, review papers and a small number of studies claiming to be experimental studies but are actually surveys were excluded, leaving a total of 253 articles.	cache/bcpe-778.pdf	txt/bcpe-778.txt