"Equations are simply a mathematical shorthand for conveying sets of ideas or concepts"
學習統計模型方程式就像學習語言一樣,我們絕對鼓勵讀者「完全弄懂」這篇所要討論的概念。妥善運用統計推論是成功分析生物多樣性研究的核心技能。由於生物多樣性怡就常見的柱況是樣本數太少,或是有部份不確定的估計。統計推論可視為執行研究的嚴謹方法,描繪議題結論的方針,妥善處理取樣上的變異。
"Likelihood" "maximum likelihood estimation" "likelihood ratio test" "goodness of fit test" "Bayesian methods"
"Akaike Information Criteria AIC"
1. 定義與基本概念
希望瞭解研究目標族群中未知的參數,則須在取樣單位(sampling unit)中以適當的取樣過程(sampling procedure),取出可描繪族群母體的樣本資料。
Population 族群: The complete set of sampling units that we are interested in studying.
Sample 樣本: (1) The set of sampling units that we actually study.
(2) A part of the population.
(3) Chosen based on some assumed probability mechanism.
Parameter 參數: (1) A characteristic of the population that we would like to know about
the probability of occupancy
Estimator of a Parameter 參數的估計值: as we never know the value of a parameter exactly, we have to use an estimator of the parameter based on a sample
the estimator of the parameter
Random Variables, Probability Distributions and the Likelihood Function
random variable 隨機變數:以隨機過程觀察所得的結果。
<範例>
有五個樣區,假設偵測度沒有問題,結果其中兩個樣區有發現目標物種、三個沒有。
U 代表 unoccupied、O 代表 occupied
學習統計模型方程式就像學習語言一樣,我們絕對鼓勵讀者「完全弄懂」這篇所要討論的概念。妥善運用統計推論是成功分析生物多樣性研究的核心技能。由於生物多樣性怡就常見的柱況是樣本數太少,或是有部份不確定的估計。統計推論可視為執行研究的嚴謹方法,描繪議題結論的方針,妥善處理取樣上的變異。
"Likelihood" "maximum likelihood estimation" "likelihood ratio test" "goodness of fit test" "Bayesian methods"
"Akaike Information Criteria AIC"
1. 定義與基本概念
希望瞭解研究目標族群中未知的參數,則須在取樣單位(sampling unit)中以適當的取樣過程(sampling procedure),取出可描繪族群母體的樣本資料。
Population 族群: The complete set of sampling units that we are interested in studying.
Sample 樣本: (1) The set of sampling units that we actually study.
(2) A part of the population.
(3) Chosen based on some assumed probability mechanism.
Parameter 參數: (1) A characteristic of the population that we would like to know about
Estimator of a Parameter 參數的估計值: as we never know the value of a parameter exactly, we have to use an estimator of the parameter based on a sample
Random Variables, Probability Distributions and the Likelihood Function
random variable 隨機變數:以隨機過程觀察所得的結果。
<範例>
有五個樣區,假設偵測度沒有問題,結果其中兩個樣區有發現目標物種、三個沒有。
U 代表 unoccupied、O 代表 occupied
U, O, U, O, U
定義發現該物種(O)的機率是
沒發現(U)的機率則是
發生U, O, U, O, U這個狀況的機率是這個樣子的:
好,然後我們設定random variable 為 x ,也就是 有發現目標物種的樣區數,在這個例子 x=2
這個例子就會變成二項分配(binomial distribution)
歸納一下就變成以下式子,s 代表調查的總樣區數、x 代表有發現目標物種的樣區數