To extract keywords from a text column

1. Right-click the column and select Keyword extraction from the context menu.

2. Provide a name to the resultant column in the New column name section.

3. Provide the maximum number of keywords you wish to extract from the column data under the Max keywords to extract section.

4. Provide the maximum number of keywords available in a phrase under the Max keywords in key phrases section. This indicates the maximum number of words in a single keyword set. For example, for the sentence "Operating System", the key length value can only be up to 2.

5. Select the type of keywords you wish to extract. The different types of keywords that can be extracted are:

• Only valid keywords - extracts only the valid keywords from each cell.
  
  
  

• Ranked keywords - extracts and scores keywords from each cell.
  
  
  

• Ranked keywords with index - extracts and ranks keywords along with index and frequency from each cell.

6. DataPrep shows a live preview of the column during the transform. You can click the Preview button at the bottom of the side panel to preview the output column. 

To apply filters

If you want to apply some filters along with this transform, you can use the filters functionality.

1. Click the  Filters  tab.

2. Click the   icon and add the required columns in the  Filters section. You can also reorder the filters using the drag and drop method.

3. For every column added, you can select one of the following options from the drop-down:

1. Actual: This option lets you filter rows based on the actual values in the column. Click  here to know more.
2. Data quality: This option lets you filter rows based on the quality of data in the column. Click  here to know more.
   
3. Patterns: This option helps you filter rows based on the data patterns in the selected column. Click  here to know more.
4. Outliers: This option allows you to filter rows based on the outliers present in the data of the selected column. Click  here to know more. 

Note: The filter options are displayed based on the datatype of the column added for the filter.

4. When you add more than one filter to the  Filters section, the logical operators, AND or OR appear next to the filters. You can click to toggle the logical operator between AND and OR.

1. Using the logical operators, you can combine the conditions and apply logic to determine the rule of precedence. The final expression is displayed in the  Criteria expression box. You can click  Edit  to alter the default expression using logical operators and parenthesis to specify the precedence or the sequential order as to which condition should be evaluated first. Click  Save after making the required changes. 
   

1. For example, In the expression, ((1 OR 2) AND (3 OR 4)) , at first the condition ( 1 OR 2 ) will be executed and the condition ( 3 OR 4 ) will be executed next. Thirdly, since, the AND operator is used, the filter will be applied when both the conditions are true.

5. You can further drill down to choose specific values based on the filter option selected for each filter, in the next section.

For example, in the above screenshot, the  Data quality  option is selected for the All columns filter in the  Filters section. Based on the selection, further options to filter specific values are displayed in the  All columns (Data quality) section.

6. You can choose to include or exclude the selected items in the last section.

7. If you want to remove all the filters for some reason, you can use the  Clear button.

8.  A live preview of the filter transform is shown as you make changes. 

9. Click the  Apply button to apply the transform along with the filters.