假設(shè)檢驗相關(guān)知識簡介-文庫吧
2025-02-09 11:34 本頁面
【正文】 of sample means, variances and sample standard deviation to investigate difference and cause/ effect relationships using data. Hypothesis Tests help determine if an apparent difference is real or could be due to chance. By using data and hypothesis testing, we can quantify our level of confidence that the difference is real. 13 假設(shè)檢驗 ? 對參數(shù)特征值估計和可信區(qū)間的詮釋都是得出樣本數(shù)據(jù)推論的路徑 . ? 假設(shè)檢驗是用以幫助我們在需要的可信度上對真實的總體數(shù) 值進行推論的。 ? 我們將用可信區(qū)間和樣本均值、 樣本差異 及樣本標準偏差測驗來研究使用數(shù)據(jù)的差別和因果關(guān)系。 假設(shè)檢驗有助于判斷一個明顯的差別是否真實存在還是偶然的，而且還可以提高差異真實性的可信度 . 14 A Statistical Hypothesis An assertion or conjecture about one or more parameters of the population ?To determine whether it is true or false, we must examine the entire population. This is impossible!! ? Instead use a random sample to provide evidence that either supports or does not support the hypothesis. ? The conclusion is then based upon statistical significance. ? It is important to remember that this conclusion is an inference about the population determined from the sample data. 15 統(tǒng)計假設(shè) 對于一個或多個總體里的參數(shù)的肯定或推斷 ?為了判斷它的正誤，我們必須檢查總體的全部。這是不可能的??！ ?我們應(yīng)使用隨機樣本，觀察其是否能支持該假設(shè) . ?從而該結(jié)論是建立在統(tǒng)計學(xué)意義的基礎(chǔ)之上的 . ?必須記住該有關(guān)總體的結(jié)論是由樣本推測出的 . 16 Why Do Hypothesis Testing? 1. To improve processes, we need to identify factors which impact the mean or standard deviation. 2. Once we have identified these factors and made adjustments for improvement, we need to validate actual improvements in our processes. 3. Sometimes we cannot decide graphically or by using calculated statistics (sample mean and standard deviation) if there is a statistically significant difference between processes. 4. In such cases the decision will be subjective. 5. We perform a formal statistical hypothesis test to decide objectively whether there is a difference. Data helps everyone makes the same decision. 17 為何要做假設(shè)檢驗 ? 1. 為了改進過程，我們需要確定影響均值和標準偏差的因素 . 2. 一旦確定了這些因素并對改進措施進行了調(diào)整，我們就需要驗證其在過程中的切實效果。 3. 若過程中存在統(tǒng)計上的重大差別，有時我們就不能利用圖表或算得的統(tǒng)計數(shù)據(jù)（樣本均值和樣本標準偏差）作出決策 . 4. 在這種情況下，決定可能是主觀的 . 5. 我們采用正統(tǒng)假設(shè)檢驗以客觀地判斷是否存在差別。 數(shù)據(jù)幫助 每個 人作出同樣的決定。 18 Nature of Hypotheses ? Null Hypothesis (Ho): ? Usually describes a status quo ? The one you assume unless otherwise shown ? Signs used in Minitab: = ? Alternative Hypothesis (Ha ): ? Usually describes a difference ? The one you accept or reject based upon evidence ? Signs used in Minitab: not =or or Or Its either Null (same) or Alternative (Different) 19 假設(shè)的種類 ? 虛 無 性假設(shè) ? 通常用以描述現(xiàn)狀 ? 除非其它方面有所說明，否則就是人為設(shè)想的。 ? 在 Minitab中用“ =”表示
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