What is the Covering (Rule-based) algorithm? Classification Rules- Straightforward 1. If-Then rule 2. Generating rules from Decision Tree Rule-based Algorithm 1. The 1R Algorithm / Learn One Rule 2. The PRISM Algorithm 3. Other Algorithm Application of Covering algorithm Discussion on e/m-learning application

1. Chapter 8 Covering (Rules-based) Algorithm Data Mining Technology

2. Chapter 8 Covering (Rules-based) Algorithm Written by Shakhina Pulatova Presented by Zhao Xinyou [email_address] 2007.11.13 Data Mining Technology Some materials (Examples) are taken from Website.

5. Introduction-App-2 PP87-88 How to get all tall people from B based on A A B + Training Data

11. Generating rules from Decision Tree -1-Con’ Decision Tree 2

12. Generating rules from Decision Tree -2-Con’ y n a b c d x y y

13. Generating rules from Decision Tree -3-Con’

23. Example 5 – 1R-3-Con’ Rules based on height … ... … 0/2 0/2 0/3 0/4 1/2 0/2 3/9 3/6 Error 1/15 (0 , 1.6]-> short (1.6, 1.7]->short (1.7, 1.8]-> medium (1.8, 1.9]-> medium (1.9, 2.0]-> medium (2.0, ∞ ]-> tall Height (Step=0.1) 2 6/15 F->medium M->tall Gender 1 Total Error Rules Attribute Option

24. Example 6 -1R PP92-93 5/14 2/8 3/6 False->yes True->no windy 4 4/14 3/7 1/7 High->no Normal->yes humidity 3 2/4 2/6 1/4 2/5 0/4 2/5 Error 5/14 Hot->no Mild->yes Cool->yes temperature 2 4/14 Sunny->no Overcast->yes Rainy->yes outlook 1 Total Error Rules Attribute Rules based on humidity OR High->no Normal->yes Rules based on outlook Sunny->no Overcast->yes Rainy->yes

26. PRISM Algorithm Step Input D and C (Attribute -> Value) 1.Compute all class P/T (Attribute->Value) 2. Find one or more pair of (Attribute->Value) P/T = 100% 3. Select (Attribute->Value) as Rule 4. Repeat 1-3 until no data in D Input: D //Training Data C //Classes Output: R //Rules

27. Example 8-Con’-which class may be tall? Compute the value p / t Which one is 100% PP94-95 0/9 Gender = F 1 2/2 2.0< Height 8 ½ 1.9< Height ≤ 2.0 7 0/4 1.8< Height ≤ 1.9 6 0/3 1.7< Height ≤ 1.8 5 0/2 1.6< Height ≤ 1.7 4 0/2 Height ≤ 1.6 3 3/6 Gender = M 2 p / t (Attribute, value) Num R1 = 2.0< Height

28. R2 = 1.95< Height ≤ 2.0 R = R1 U R2 PP94-96 … … … 1/1 1.95< Height ≤ 2.0 0/1 1.9< Height ≤ 1.95 p / t (Attribute, value) Num

29. Example 9-Con’-which days may play? The predicate outlook=overcast correctly implies play=yes on all four rows R1 =if outlook=overcast, then play=yes Compute the value p / t

30. Example 8-Con’ R2= if humidity=normal and windy=false, then play=yes

31. Example 8-Con’ R3 =….. R = R1 U R2 U R3 U…

34. Discussion