Lesson_3_Data_Cleaning_and_Preparation.pdf
- 1. Business Analytics with Excel
- 2. Data Cleaning and Preparation
- 3. Learning Objectives By the end of this lesson, you will be able to: Implement sort and filter functionalities to order or filter data Organize the data using group by and ungroup functions Execute Remove duplicates function to rid the data of duplicates Implement data validation function to a given data
- 4. A Day in the Life of Business Analyst As a business analyst of an organization: You are required to sort and filter data.Also, improper data needs to be eliminated and data must be cleaned and be meaningful which serves the business purpose of the organization To achieve these tasks, you will be learning a few concepts, such as sort, filter, group by, subtotal and removing duplicates.
- 6. Sort and Filter The sort and filter functionalities are available in Excel to order or filter the data for further analysis.
- 7. Example: The results of nine students for the Maths subject. Sort and Filter
- 8. Steps to Sort Value To sort the data based on the CGPA in descending order, choose the CGPA column name and then click on Sort under the Data tab
- 9. Under sort columns, choose CGPA and then select ‘Largest to Smallest’ Steps to Sort Value
- 10. These are the sorted values: Steps to Sort Value
- 11. Sorting can be done based on character values from either A-Z or Z-A. Steps to Sort Value Any type of data can be sorted based on multiple columns
- 12. Steps to Sort Value Under the Sort by tab, select Name and choose order as A to Z and click OK
- 13. The results will be in the following order. Steps to Sort Value
- 14. Filter option allows us to choose any column we would like to filter the data on. Filter
- 15. Choose a column to filter and in the Data tab, click on Filter Steps to Filter Data
- 16. Example: To view CGPA’s that are greater than or equal to four. Steps to Filter Data
- 17. Choose the greater than or equal to option from the dropdown, and then mention the number In this case, it is 4.0. Steps to Filter Data
- 18. The result will be in the following order. Steps to Filter Data
- 19. Group by and Subtotal
- 20. Group by and Ungroup Group by and ungroup allow data to group data by collapse and expanding rows with similar content to create more compact and understandable views. Group by and ungroup by are available under the Data tab within the outline section.
- 21. Group By The group by functionality in Excel allows us to show necessary data for easy viewing and analysis. It is possible to create subtotals and outline for a given set of data.
- 22. Group By Group by can be done for rows or columns. Grouping for Columns Grouping for Rows
- 23. Steps for Grouping Step 1: To group data, select the rows and columns you want to group Let us discuss the steps for grouping data.
- 24. Steps for Grouping Step 2: Click on Group under Data tab
- 25. Grouping for Columns Step 3: Choose Columns and click on OK
- 26. Grouping for Columns Step 4: This groups the three columns chosen, and applies a control to show or hide the grouped content
- 27. Grouping for Columns Clicking on – hides the content, while clicking on + shows the grouped content.
- 28. Grouping for Rows Similarly, for row-wise grouping, select the rows you want to group.
- 29. Grouping for Rows Step 1: Click on Group under the Data tab, and then select rows option from the dialog box Step 2: Click on OK
- 30. Grouping for Rows Clicking on – hides the content and clicking on + shows the grouped content.
- 31. Grouping for Rows We can create a group within a group by choosing rows or columns within the grouped data. Create a row or column group again.
- 32. Grouping for Rows This will be the result.
- 33. Ungrouping The ungroup option allows us to remove the groups created by group. Step 1: Choose the data already chosen for grouping (row/column)
- 34. Ungrouping Step 2: Click on Ungroup under the Data tab
- 35. Ungrouping Step 3: Choose Rows to remove row-level grouping
- 36. Ungrouping Step 4: The group chosen will be removed
- 37. Subtotal Subtotal allows us to create groups and have a subtotal for each group.
- 38. Subtotal: Example Let us understand this by taking an example. For the following data set, find the total per student by grouping students and adding their marks.
- 39. Subtotal: Example Step 1: Select the data we need to group by and subtotal
- 40. Subtotal: Example Step 2: Click on Subtotal under Data tab
- 41. Subtotal: Example Step 3: Click on the column to which the sum function has to be applied
- 42. Subtotal: Example The subtotaling provides control to the group and shows subtotals per student.
- 43. Text to Column
- 44. It converts raw text into columns in excel, which can save a user the time of manually separating the text in a cell into several columns. Text to Column Raw text Text put in excel columns Name, age, address, phone number, university Tom Smith, 22,4th street, 8998798901, St Gallen University
- 45. Text to Column: Example Step 1: Open Excel and paste the content into a sheet
- 46. Text to Column: Example Step 2: Choose Column A
- 47. Step 2: Choose column A and click on text to columns under Data tab. Text to Column: Example Step 3: Go to the Data tab and click on Text to Columns
- 48. Step 4: Select the Delimited option in the dialog box and click Next Text to Column: Example
- 49. Step 5: Choose Comma and click Next, since the delimiter is a comma here. Text to Column: Example
- 50. The text to column function puts each element separated by comma in an individual box Text to Column: Example
- 52. Duplicate Duplicate refers to a copy of the original.
- 53. Removing Duplicates in Excel In any data analytics work, there will always be cases where we get duplicates in different columns. Excel is very handy in removing duplicates in the data.
- 54. Causes of Duplicates Duplicates can occur in data and cause errors in analytics. Duplicates occur when there is an incorrect submission of user data.
- 55. Causes of Duplicates When there is a missing validation in the data set.
- 56. Causes of Duplicates Duplicates occur when we merge multiple data sources using Joins.
- 57. Causes of Duplicates When data is copy pasted multiple times. When duplicates are removed using Excel, we can choose a single column or multiple columns to check the data.
- 58. Removing Duplicates Using Single Column: Example Step 1: Choose the column with a set of rows to remove duplicates There are many duplicates in this column.
- 59. Removing Duplicates Using Single Column: Example Step 2: • Select the entire column • Click on Data • Click on Remove Duplicates
- 60. Removing Duplicates Using Single Column: Example Click OK Step 3: After clicking the option a pop up will appear
- 61. Removing Duplicates Using Single Column: Example Step 4: It is clearly visible that all the duplicates are removed
- 62. Removing Duplicates Using Multiple Columns: Example • Here, there are two entries for Maths subject under the same name, Albert Dane. • When removing duplicates for this, only the first row is retained. Let us consider the following data set as an example for removing duplicates with multiple columns:
- 63. Removing Duplicates Using Multiple Columns: Example Step 1: Let us choose the data to remove duplicates
- 64. Removing Duplicates Using Multiple Columns: Example Step 2: Now click on Remove Duplicates from Data tab
- 65. Removing Duplicates Using Multiple Columns: Example Step 3: Choose the columns where duplicates need to be checked A pop up will occur to remove duplicates.
- 66. Removing Duplicates Using Multiple Columns: Example Step 4: Once it is checked, click OK
- 67. Removing Duplicates Using Multiple Columns: Example Another pop up will appear which notifies that, 1 duplicate value was found and removed, also 3 unique values remain.
- 68. Removing Duplicates Using Multiple Columns: Example This is the final data set
- 69. Data Validation
- 70. Data Validation Data in Excel can be validated using some rules set in data validation dialog. This helps in reducing the amount of unstandardized data, errors, or irrelevant information in the worksheet.
- 71. Data Validation: Example • Choose a cell or a group of cells to validate • Click on Data Validation under Data tab Let us understand data validation through an example.
- 72. Data Validation: Example It is important to remember that: • Validation applies to new data entered in the cells where rules are placed. • Existing data is not validated.
- 73. Data Validation: Example ‘Any value’ allows any alphanumeric value in the cells. After clicking on the data validation, a pop-up appears regarding the validation criteria and the following validations are possible.
- 74. Data Validation: Example ‘Whole number’ allows whole numbers and a set of rules including a range of minimum and maximum to be set.
- 75. Data Validation: Example ‘List’ allows only a list of values specified in a range of cells or written manually in the ‘source’ input box.
- 76. Data Validation: Example ‘Date’ allows only dates and a set of rules including a range of minimum and maximum to be set.
- 77. Data Validation: Example ‘Time’ allows only time values and a set of rules including a range of minimum and maximum to be set.
- 78. Data Validation: Example ‘Text length’ allows only text within the specified length and a set of rules on the length to be set.
- 79. Data Validation: Example ‘Custom’ allows custom rules on data to be set.
- 80. Key Takeaways The sort and filter functionalities are available to order or filter the data for further analysis. Group by functionality in Excel allows us to show necessary data for easy viewing and analysis. The ungroup option allows us to remove the groups created by group. While removing duplicates, we can choose a single column or multiple columns to check the data. Data validation applies only to new data entered in the cells where rules are placed.
- 81. Knowledge Check
- 82. Knowledge Check a. b. c. d. 1 In which of the following sections can we find Group By and Subtotal under the data tab? Sort & Filter Data Tools Outline Analyze
- 83. Knowledge Check The correct answer is a. b. c. d. In which of the following sections can we find Group By and Subtotal under the data tab? 1 Outline section under Data tab allows group by and subtotal. Data Tools Outline Analyze Sort & Filter c
- 84. Knowledge Check a. b. c. d. 2 Group By within a Group By is possible. True or False. True False
- 85. Knowledge Check The correct answer is a. b. c. d. Group By within a Group By is possible. True or False. 2 True. Group By within a Group By is possible. False True a
- 86. Knowledge Check a. b. c. d. 3 Which of the following options can be used for sorting on multiple columns? Options Add Level Sort On Order
- 87. Knowledge Check The correct answer is a. b. c. d. Which of the following options can be used for sorting on multiple columns? 3 Add Level helps to add multiple columns for sorting. b Options Add Level Sort On Order
- 88. Knowledge Check a. b. c. d. 4 Pattern matching is possible in filters. True or False. True False
- 89. Knowledge Check The correct answer is a. b. c. d. Pattern matching is possible in filters. True or False. 4 True. Pattern matching is done using regular expressions such as ? and *. True False a
- 90. Knowledge Check a. b. c. d. 5 Which of the following options is used to convert text to columns when there is no delimiters? Delimiter Fixed Width Comma Space
- 91. Knowledge Check The correct answer is a. b. c. d. Which of the following options is used to convert text to columns when there is no delimiters? 5 Fixed width allows us to convert data into columns based on the length of each column. b Delimiter Fixed Width Comma Space
- 92. Knowledge Check a. b. c. d. 6 How to convert a CSV format data into excel? Use text to columns Use remove duplicates Use copy paste to take out each CSV value
- 93. Knowledge Check The correct answer is a. b. c. d. How to convert a CSV format data into excel? 6 Text to columns is the easiest way to convert data to columns Use text to columns Use remove duplicates Use copy paste to take out each CSV value a
- 94. Knowledge Check a. b. c. d. 7 Is it possible to separate data with multiple delimiters into columns?(Example 1,2,3;4,5|6)? True or False. True False
- 95. Knowledge Check The correct answer is a. b. c. d. Is it possible to separate data with multiple delimiters into columns?(Example 1,2,3;4,5|6)? True or False. 7 True. Multiple delimiters can be specified in Text to Columns True False a
- 96. Knowledge Check a. b. c. d. 8 Why do duplicates occur in a dataset? Missing validation Duplicates cannot occur in a dataset Excel has a feature to create duplicates
- 97. Knowledge Check The correct answer is a. b. c. d. Why do duplicates occur in a dataset? 8 Duplicates occur if the input feed has not validated the data and allowed duplicates. Missing validation Duplicates cannot occur in a dataset Excel has a feature to create duplicates a
- 98. Knowledge Check a. b. c. d. 9 How do you specify that data has header while removing duplicates? Click on "My data has headers" Checkbox Remove headers manually Cannot be specified
- 99. Knowledge Check The correct answer is a. b. c. d. How do you specify that data has header while removing duplicates? 9 The "My data has headers" checkbox specifies that the data has headers Click on "My data has headers" Checkbox Remove headers manually Cannot be specified a
- 100. Knowledge Check a. b. c. d. 10 Is it possible to remove rows in a dataset where only one row has duplicates? True or False. True False
- 101. Knowledge Check The correct answer is a. b. c. d. Is it possible to remove rows in a dataset where only one row has duplicates? True or False. 10 True. It is possible to remove all rows in a dataset where one column only has duplicates. True False a
- 102. Knowledge Check a. b. c. d. 11 Which of the following options in data validation allows us to validate a list of values? Any Value Data List Custom
- 103. Knowledge Check The correct answer is a. b. c. d. Which of the following options in data validation allows us to validate a list of values? 11 Outline section under Data tab allows group by and subtotal. Any Value Data List Custom b
- 104. Knowledge Check a. b. c. d. 12 Which of the following range of values can be provided in data validation? not between equal to greater than between
- 105. Knowledge Check The correct answer is a. b. c. d. Which of the following range of values can be provided in data validation? 12 Between allows us to set range of values. not between equal to greater than between d