描述统计 - Arca's Blog

数据

概念	定义
总体 (Population)	全部研究对象，规模 N（可无限）
样本 (Sample)	总体的子集，规模 n

名称	来源	记号
Parameter	总体 (Population)	$\mu,\sigma^2$
Statistics	样本 (Samples)	$\bar x, s^2$

目标：用样本统计量推断总体参数。

Random Sampling
Systematic Sampling: $j\in[1,n], j+n, j+2n, j+3n,\dots$
Descriptive statistics focus on graphical and numerical procedures that are used to summarize and the process data.
Inferential statistics focus on using the data to make predictions, forecasts, and estimates to make better decisions.

The target of statistics is to make decisions on a population parameter based on a sample statistic.

Sampling Error: $n\lt N$

Non-Sampling Error:

可以分为 Categorical, Numerical