Last updated: November 13, 2024
How to measure the percentage of false boolean values using a data quality check
This sample shows how to use data quality checks to detect the percentage of false boolean values and view the results on data quality dashboards.
Overview
This example shows how to detect that the percentage of false boolean values remains above a set threshold.
PROBLEM
The Federal Communication Commission (FCC) political ads public inspection files dataset contains political ad file information that broadcast stations have uploaded to their public inspection files, which are housed on the FCC website.
This information is uploaded to the FCC’s website in PDF form and not machine-readable. However, this dataset includes a content_info table that contains manual annotations of some data fields like advertiser, gross spend, ad air dates and a link to a copy of the PDF, which can be found on Google Cloud Storage.
The invalidOcr
column indicates if the OCR does match the raw file text (false value) or does not (true value). In case
of the true value, the OCR process needs more work and the file is not ready to be transcribed.
We want to verify the percentage of false boolean values in the invalidOcr
column, which will tell us what percentage of data is
ready to be transcribed.
SOLUTION
We will verify the data of bigquery-public-data.fcc_political_ads.content_info
using monitoring
false_percent column check.
Our goal is to verify that the percentage of false boolean values on invalidOcr
column does not fall below 99%.
In this example, we will set three minimum percentage threshold level for the check:
- fatal: 99.0%
If you want to learn more about checks and threshold levels, please refer to the DQOps concept section.
VALUE
If the percentage of data that is available for transcription drops below 99%, a fatal error alert will be triggered.
Data structure
The following is a fragment of the bigquery-public-data.fcc_political_ads.content_info
dataset. Some columns were omitted for clarity.
The invalidOcr
column of interest contains both TRUE and FALSE values.
contentInfoId | advertiser | grossSpend | infoSource | invalidOcr |
---|---|---|---|---|
5116276091387904 | J Hawley for Missouri Senate-R | 2847500 | MANUAL | TRUE |
5101779805011968 | Friends of Michael Guest | 307500 | MANUAL | FALSE |
5948640182927360 | ALISON HARTSON 2018 | 360000 | MANUAL | FALSE |
5724690924437504 | Friedman for Congress | 2247500 | MANUAL | TRUE |
5660449924186112 | WALDEN, GREG | 85000 | MANUAL | FALSE |
4831078887981056 | ASHFORD FOR CONGRESS | 1557500 | MANUAL | FALSE |
6030938634977280 | Dr. Jim Maxwell | 2735000 | MANUAL | TRUE |
5199588961026048 | CROWLEY FOR CONGRESS | 1170000 | MANUAL | FALSE |
4925540251205632 | Alaskans For Don Young | 1500800 | MANUAL | FALSE |
5155591651590144 | POL/ Ted Cruz/R/US SEN / TX | 1610000 | MANUAL | FALSE |
Run the example using the user interface
A detailed explanation of how to start DQOps platform and run the example is described here.
Navigate to a list of checks
To navigate to a list of checks prepared in the example using the user interface:
-
Go to the Monitoring section.
The Monitoring Checks section enables the configuration of data quality checks that are designed for the daily and monthly monitoring of your data source.
-
Select the table or column mentioned in the example description from the tree view on the left.
On the tree view you can find the tables that you have imported. Here is more about adding connection and importing tables.
-
Select the Data quality check editor tab.
This tab displays a list of data quality checks in the check editor. Learn more about navigating the check editor.
Run checks
Run the activated check using the Run check button.
You can also run all the checks for an entire subcategory of checks using the Run check button at the end of the line with the check subgroup name.
View detailed check results
Access the detailed results by clicking the Results button. The results should be similar to the one below.
Within the Results window, you will see four categories: Check results, Sensor readouts, Execution errors, and Error sampling. The Check results category shows the severity level that result from the verification of sensor readouts by set rule thresholds. The Sensor readouts category displays the values obtained by the sensors from the data source. The Execution errors category displays any error that occurred during the check's execution. The Error sampling category displays examples of invalid values in the column.
The actual value in this example is 99.9%, which is above the minimum threshold level set in the warning (99%). The check gives a correct result (notice the green square to the left of the check name).
Synchronize the results with the cloud account
Synchronize the results with your DQOps cloud account using the Synchronize button located in the upper right corner of the user interface.
Synchronization ensures that the locally stored results are synced with your DQOps Cloud account, allowing you to view them on the dashboards.
Change a schedule at the connection level
With DQOps, you can easily customize when checks are run by setting schedules. You can set schedules for an entire connection, table, or individual check.
After importing new tables, DQOps sets the schedule for 12:00 P.M. (noon) every day. Follow the steps below to change the schedule.
-
Navigate to the Data Source section.
-
Choose the connection from the tree view on the left.
-
Click on the Schedule tab.
-
Select the Monitoring daily tab
-
Select the Run every day at and change the time, for example, to 10:00. You can also select any other option.
-
Once you have set the schedule, click on the Save button to save your changes.
By default, scheduler is active. You can turn it off by clicking on notification icon in the top right corner of the screen, and clicking the toggle button.
Once a schedule is set up for a particular connection, it will execute all the checks that have been configured across all tables associated with that connection.
You can read more about scheduling here.
You might also want to check the Running checks with a scheduler example.
YAML configuration file
The YAML configuration file stores both the table details and checks configurations.
In this example, we have set the minimum percentage threshold level for the check:
- fatal: 99.0%
The highlighted fragments in the YAML file below represent the segment where the monitoring daily_false_percent
check is configured.
If you want to learn more about checks and threshold levels, please refer to the DQOps concept section.
apiVersion: dqo/v1
kind: table
spec:
incremental_time_window:
daily_partitioning_recent_days: 7
monthly_partitioning_recent_months: 1
columns:
grossSpend:
type_snapshot:
column_type: INT64
nullable: true
infoSource:
type_snapshot:
column_type: STRING
nullable: true
invalidOcr:
type_snapshot:
column_type: BOOL
nullable: true
monitoring_checks:
daily:
bool:
daily_false_percent:
fatal:
min_percent: 99.0
In this example, we have demonstrated how to use DQOps to verify the reasonability of data in a column. By using the false_percent column check, we can monitor that the percentage of false boolean values does not fall below a set threshold. If it does, you will get a fatal result.
Next steps
- You haven't installed DQOps yet? Check the detailed guide on how to install DQOps using pip or run DQOps as a Docker container.
- For details on the profile_false_percent check used in this example, go to the check details section.
- You might be interested in another reasonability check that evaluates that percentage of integer values from a range in a column does not exceed the minimum accepted percentage.
- With DQOps, you can easily customize when the checks are run at the level of the entire connection, table, or individual check. Learn more about how to set schedules here.
- DQOps provide you with summary statistics about your table and column. This information can be valuable in deciding which data quality checks and threshold levels should be set to monitor data quality. For more details about Basic data statistics, click here.