量化社会科学导论
最新书摘：
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Graciosa2023-09-14Step 1: Choose the initial centroids of k clusters.Step 2: Given the centroids, assign each observation to a cluster whose centroid is the closest (in terms of Euclidean distance) to that observation.Step 3: Choose the new centroid of each cluster whose coordinate equals the within-cluster mean of the corresponding variable.Step 4: Repeat Step 2 and 3 until cluster assignments no longer change.
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Graciosa2023-09-14The k-means algorithm is an iterative algorithm in which a set of operations are repeatedly performed until a noticeable difference in results is no longer produced. The goal of the algorithm is to split the data into k similar groups where each group is associated with its centroid, which is equal to the within-group mean.
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Graciosa2023-09-14The natural logarithm transformation is often used to correct the skewness of variables such as income and population that have a small number of observations with extremely large or small positive values.
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Graciosa2023-09-14"A pretreatment variable that is associated with both the treatment and the outcome variables is called a confounder and is a source of confounding bias in the estimation of the treatment effect."
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Graciosa2023-09-14"in observational studies, researchers simply observe naturally occurring events and collect and analyze the data."
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Graciosa2023-09-14"each unit is randomly assigned either to the treatment or control group. The randomization of treatment assignment guarantees that the average difference in outcome between the treatment and control groups can be attributed solely to the treatment, because the two groups are on average identical to each other in all pretreatment characteristics."
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Graciosa2023-09-14"we observe only one of the two potential outcomes, and which potential outcome is observed depends on the treatment status. Formally, the observed outcome Yi is equal to Yi (Ti)."
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梅尔基亚德斯2022-01-03向更透明和数据驱动的探索转变，需要社会科学的研究者学习如何分析数据，解释结果，并有效地表达他们的实证研究结果。传统上，入门统计课程的重点是教学生基本的统计概念，让他们用纸和铅笔，或充其量用一个计算器进行科学计算。虽然这些概念在本书中仍然很重要，但这种传统的方法不能满足当前社会的需求。通过学习常见的统计概念和方法来实现“统计素养”是不够的。相反，所有社会科学的研究者都应该掌握基本的数据分析技能以便利用大量的机会从数据中学习，并通数据驱动的探索为社会做出贡献。
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欸弗里德里奇2021-10-141.5.1 2 根据投票年龄人口或VAP计算投票率原文：Calculate the turnout rate based on the voting age population or VAP.意思是根据投票年龄人口（VAP）计算投票率1.5.1 6 其次，计算调整后的VAP投票率，注意减去2008年的选票总数原文：substract the number of overseas ballots counted from the total ballots in 2008意思是，注意将海外选民统计的总票数从总票数中减去1.5.2 2 公式部分 [x, x+ε)年龄段女性人数原文：number of births to women of age[x, x+ε)问题部分：这些AFSRs的模式对瑞典和肯尼亚妇女的生育有什么影响？What does the pattern of these AFSRs say about reproduction among Sweden and Kenya