Ignoring Commonly Occuring Words While Matching

Common words like Mr, Pvt, Av, St, Street etc. do not add differential signals and confuse matching. These words are called stopwords and matching is more accurate when stopwords are ignored.

The stopwords can be recommended by Zingg by invoking:

./scripts/zingg.sh --phase recommend --conf <conf.json> --column <name of column to generate stopword recommendations>

The stopwords generated are stored at the location - models/100/stopWords/columnName. This will give you the list of stopwords along with their frequency.

By default, Zingg extracts 10% of the high-frequency unique words from a dataset. If the user wants a different selection, they should set up the following property in the config file under the respective field for which they want stopwords:

stopWordsCutoff: <a value between 0 and 1>

Once you have verified the above stop words, you can configure them in the JSON variable stopWords with the path to the CSV file containing them. Please ensure while editing the CSV or building it manually that it should contain one word per row. Also, ensure that it has a header such as StopWords as Zingg ignores the header by default and works on the remaining data.

"fieldDefinition":[
   	{
   		"fieldName" : "fname",
   		"matchType" : "fuzzy",
   		"fields" : "fname",
   		"dataType": "string",
   		"stopWords": "models/100/stopWords/fname.csv"
   	},

In case of stopwords being set up manually by the user, the list of stopwords may consider multiple columns and Zingg used only the first column by default.

For recommending stopwords in Zingg Enterprise Snowflake,

./scripts/zingg.sh --phase recommend --conf <conf.json> --properties-file <path to Snowflake properties file> --column <name of column to generate stopword recommendations>

The stopwords generated are stored in the table - zingg_stopWords_columnName_modelId where we can see the list of stopwords and their frequency associated with the given column name.