Decision Tree and Tables
- 1. DECISION TREES AND TABLES Divya Sure 17MIS7054
- 2. What is decision tree? • A decision tree is a graphical representation of possible solutions to a decision based on certain conditions. • Decision tree requires a systematic, documented thought process. • Decision trees shows each decision sequentially. • Provides for randow elements for business conditions that will be related in future.
- 3. Decision tree in various sectors: • Decision tree diagrams are often used by businesses to plan a strategy, analyze research, and come to conclusions. • Lenders and banks use decision trees to calculate the riskiness of loans and investment opportunities.
- 4. Elements of decision tree indicates condition indicates an action
- 5. Limitations for Decision Tree: • The biggest limitation of our decision making is that we can only selecting from the known alternatives • Provide less information of the relationship
- 6. Advantages: • Easy to Understand • Useful in Data exploration • Less data cleaning required. • Data type is not a constant. • Decision trees help formalize the brainstorming process so we can identify more potential solutions. • The advantages of a decision tree are fairly obvious: a “path” through possibilities, with alternatives, leading toward a desirable outcome.
- 7. Disadvantages: • Over fitting • Not fit for continous variables. • Loss of innovation-only past experience go into the branching of choices, new ideas donot get much consideration
- 8. Example: if student got marks >=90 percent then allot first category else if student got marks >=80 percent then allot second category else if student got marks>=50 percent&&<80 then allot third category else No admission end if else go to third category end if end if
- 10. Decision Tables: • Decision tables are visual representation for specifying which actions to perform depending on given conditions. • Information in decision tables could also be represented as decision trees or in a programming language as a series of if- then-else and switch-case statements.
- 11. Why use decision tables? • Powerful visualization • Preventing errors is easier
- 12. Advantages: • A decision table may be easier to construct than a flowchart. • It is possible to check that all test combinations have been considered. • The tables show cause and effect relationships. • They use standardized format. • Easily understood making it very effective for communication between analysts or programmers and non-technical users.
- 13. Disadvantages: • The total sequence is not clearly shown, i.e., no overall picture is given by decision tables as presented by flowcharts. • Where the logic of a system is simple, flowcharts nearly always serve the purpose better than a decision table.
- 14. Steps to draw decision table: 1.Analyze the requirement and create the first coloumn. 2.Add coloumn 3.Reduce the table. Mark insignificant values with”-”. 4.Determine actions 5.Write test cases
- 15. Conditio ns Rule 1 Rule 2 Rule 3 Rule 4 Rule 5 Rule 6 Rule 7 Rule 8 marks>= 90percen t N N N N T T T T marks>= 80percen t N N T T - - - - marks>= 50%&&< 80% N T - - - - - - Actions First Category - - - - X X X X Second Category - - X X - - - - Third Category -ss X - - - - - - No admissio n X - - - - - - -
- 16. References: • https://www.slideshare.net/DMANIMALA/decision-table-44548879 • http://www.answers.com/Q/What_are_advantages_and_disadvantages_of_d ecision_tables • https://www.coursehero.com/file/p4bc0fm/What-are-the-Advantages-of- Decision-Tables-1-This-type-of-testing-also-works/ • http://tryqa.com/what-is-decision-table-in-software-testing/ • https://en.wikipedia.org/wiki/Decision_table • https://study.com/academy/lesson/what-is-a-decision-tree-examples- advantages-role-in-management.html • https://en.wikipedia.org/wiki/Decision_tree • https://www.analyticsvidhya.com/blog/2016/04/complete-tutorial-tree-based- modeling-scratch-in-python/
- 18. THANK YOU