Text Classification

Model training requires a large amount of labeled data. Therefore, before the model training, add labels to the files that are not labeled. In addition, you can modify, delete, and re-label the labeled text.

Text classification classifies text content based on labels. Before labeling text content, pay attention to the following:

Text labeling supports multiple labels. That is, you can add multiple labels to a labeling object.
A label name can contain a maximum of 1024 characters, including letters, digits, hyphens (-), underscores (_), and special characters.

Data management is being upgraded and is invisible to users who have not used data management.

Starting Labeling

Log in to the ModelArts management console. In the left navigation pane, choose Data Management > Label Data.
In the labeling job list, select a labeling type from the All type drop-down list, click the job to be performed based on the labeling type. The details page of the job is displayed.
Figure 1 Selecting a labeling type
The job details page displays all data of the labeling job.

Synchronizing New Data

ModelArts automatically synchronizes data and labeling information from datasets to the labeling job.

To quickly obtain the latest data in the datasets, on the Unlabeled tab page of the labeling job details page, click Synchronize New Data.

Symptom:

After the labeled data is uploaded to OBS and synchronized, the data is displayed as unlabeled.

Possible causes:

Automatic encryption is enabled in the OBS bucket.

Solution:

Create an OBS bucket and upload data again, or disable bucket encryption and upload data again.

Labeling Text Files

The labeling job details page displays the Unlabeled and Labeled tabs. The Unlabeled tab page is displayed by default.

On the Unlabeled tab page, the objects to be labeled are listed in the left pane. In the list, click the text object to be labeled, and select a label in the Label Set area in the right pane. Multiple labels can be added to a labeling object.
You can repeat this operation to select objects and add labels to the objects.

Figure 2 Labeling for text classification
After all objects are labeled, click Save Current Page at the bottom of the page.

Adding a Label

Adding labels on the Unlabeled tab page: Click the plus sign (+) next to Label Set. On the Add Label page that is displayed, add a label name, select a label color, and click OK.
Figure 3 Adding a label (1)
Adding labels on the Labeled tab page: Click the plus sign (+) next to Label Set. On the Add Label page that is displayed, add a label name, select a label color, and click OK.
Figure 4 Adding a label (2)

Figure 5 Adding a label

Viewing the Labeled Text

On the labeling job details page, click the Labeled tab to view the list of labeled texts. You can also view all labels supported by the labeling job in the All Labels area on the right.

Modifying Labeled Data

After labeling data, you can modify labeled data on the Labeled tab page.

Modifying based on texts
On the labeling job details page, click the Labeled tab and select the text to be modified from the text list.

In the text list, click the text. When the text background turns blue, the text is selected. If a text file has multiple labels, you can click above a label to delete the label.

Modifying based on labels
On the labeling job details page, click the Labeled tab. The information about all labels is displayed on the right.
- Batch modification: In the All Labels area, click the edit icon in the Operation column, modify the label name in the text box, select a label color, and click OK.
- Batch deletion: In the All Labels area, click the deletion icon in the Operation column to delete the label. In the dialog box that is displayed, select Delete the label or Delete the label and objects with only the label, and click OK.

Adding a File

In addition to the data synchronized, you can directly add data on labeling job details page for labeling.

On the labeling job details page, click the Unlabeled tab, click Add data in the upper left corner.
Configure input data and click OK.
For details about how to import data, see Importing Data.
Figure 6 Importing data

Deleting a File

You can quickly delete the files you want to discard.

On the Unlabeled tab page, select the text to be deleted, and click Delete in the upper left corner to delete the text.
On the Labeled tab page, select the text to be deleted and click Delete. Alternatively, tick Select Current Page to select all text objects on the current page and click Delete in the upper left corner.

The background of the selected text is blue.

Managing Annotators

If team labeling is enabled for a labeling job, view its labeling details on the Annotator Management tab page. Additionally, you can add, modify, or delete annotators.

Choose Data Management > Label Data. On the My Creations tab page, view the list of all labeling jobs.
Locate the row that contains the target team labeling job. (The name of a team labeling job is followed by .)
Choose More > Annotator Management in the Operation column. Alternatively, click the job name to go to the job details page, and choose Team Labeling > Annotator Management in the upper right corner.
Figure 7 Annotator management (1)

Figure 8 Annotator management (2)

Adding an annotator
Click Add Member, select a member name, and click OK.

Click Send Email in the Operation column to send the labeling job to the annotator by email.
Modifying annotator information
Click Modify in the Operation column to modify the role of the annotator.
Deleting an annotator
Click Delete in the Operation column to delete the annotator.