> ## Documentation Index
> Fetch the complete documentation index at: https://moengage.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Test a Recommendation
> Preview what a real customer would see from a MoEngage recommendation, fine-tune its conditions live, and diagnose zero-result setups before you launch a campaign.
Before you use a recommendation in a live campaign, test it. Testing shows you exactly what a real customer would see, so you can catch a zero-result setup, a bad filter, or a mapping issue before it reaches your audience.
Testing works the same way for Basic recommendations, which cover Item Attribute, User Actions, and Catalog Alerts, and for Advanced recommendations, which cover all the AI-powered models.
# Test Recommendation Panel
You can open the test panel in the following two ways:
* While you create a recommendation. The last step of the setup includes the **Test recommendation** panel, so you can test the recommendation before you save it.
* From the Recommendations list. Open an existing recommendation and click **Test recommendation**.
To open the test panel for a recommendation that already exists, perform the following steps:
1. On the sidebar menu in MoEngage, hover over the Content menu item 
. The **Content** menu appears.
2. Click **Recommendations**. The Recommendations page appears.
3. Find your recommendation in the list and click the edit icon under **Actions**. The recommendation opens.
4. Scroll down to the **Test recommendation** section, and then click **Test recommendation**. The test panel opens as a popup.
While the panel opens, MoEngage displays "Calculating the eligible users for this recommendation." After the calculation finishes, the **Random eligible user** option shows the size of the qualifying pool, in the form "Test 10 users randomly preselected from N users who qualify for this recommendation."
## Panel Layout
The test panel has the following three areas:
| Area | What it contains |
| ----------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| **Show recommendation** | The three test modes, and the fields for the mode you click. This is where you choose who or what to test with. |
| **Recommendation conditions** | The **Generate Recommendation** settings and the **Filter** conditions applied to the recommendation, along with **Reset changes**. |
| **Test result** | The recommended items for the user, item, or sample you selected, headed **Preview of \[X] items**. |
The panel also has the following controls:
| Control | What it does |
| ---------- | ---------------------------------------------------------------------------------------- |
| **Hide** | Collapses the **Show recommendation** area so the results and conditions have more room. |
| **Cancel** | Closes the panel and discards any condition changes you made. |
| **Done** | Closes the panel. If you changed any conditions, MoEngage asks whether to apply them. |
# Test Modes
MoEngage offers the following three ways to preview results:
| Mode | What it does |
| ------------------------ | ---------------------------------------------------------------------------------------------------- |
| **By specific user** | Tests the recommendation for one exact user, identified by email, mobile number, ID, or MoEngage ID. |
| **Random eligible user** | Tests users preselected at random from everyone who qualifies for the recommendation, one at a time. |
| **By item** | Tests what MoEngage recommends alongside a specific product. |
**By item** is available only for Similar Items, Frequently Bought Together Items, and Frequently Viewed Together Items, because these models take a product ID as their input. Recommended Items takes a user ID, so test that model by user instead.
## Test by Specific User
To test a recommendation for a specific user, perform the following steps:
1. In the test panel, click **By specific user**.
2. In the **Select user by** drop-down list, select **ID**, **Email ID**, **Mobile Number**, or **MoEngage ID**.
3. In the **User identifier value** box, enter the value for the identifier you selected in the **Select user by** list.
4. Click **Show result**.
The recommended items appear under **Test result**.
These are the same identifier options available in campaign personalization preview, so you can test with whichever ID you already have. You do not need to look up a MoEngage ID first.
If more than one profile matches what you entered, MoEngage shows how many profiles it found and which one it selected. Use the drop-down list next to that message to switch to any of the other matched profiles, and click **View user** to open the selected profile and confirm it is the right one.
Searching by **ID**, **Email ID**, or **Mobile Number** can match several profiles, because one person can hold more than one. MoEngage tests the profile named in the message, so switch profiles if that is not the user you meant.
## Test with a Random Eligible User
To test a recommendation with a random eligible user, perform the following steps:
1. In the test panel, click **Random eligible user**.
MoEngage samples 10 users at random from everyone who qualifies for the recommendation, so you do not need to enter anything.
2. Click a user to see the recommendation results for that user.
3. Click **Test for another user** to switch to a different user from the sample.
4. Click **View user** to open the selected user's full profile.
A sampled user can return no results. This means the recommendation produced nothing for that particular user, not that the recommendation is broken. Click **Test for another user** to check a different one.
If **Random eligible user** returns no users at all, a filter on the recommendation excludes everyone. To widen the eligible pool, clear the filter in step 2 of the recommendation setup, and then test the recommendation again.
Clearing or changing a filter in the **Recommendation conditions** pane does not refresh the random eligible users. That list is built when the panel opens, and the panel's filter controls only affect the results shown on the right.
## Test by Item
To test a recommendation against a specific product, perform the following steps:
1. In the test panel, click **By item**.
2. In the **Product ID** box, enter the product ID.
3. Click **Show result**. The items MoEngage recommends alongside that product appear under **Test result**.
The product ID and the item ID are the same value. The product must exist in the catalog the recommendation uses. If it does not, MoEngage displays the error "The product ID does not exist. Please check the product ID."
# Recommendation Results
The **Test result** pane, headed **Preview of \[X] items**, shows the items MoEngage recommends for the user, item, or sample you selected. In this pane, you can perform the following actions:
* Search the results by title or ID in the **Search by title and ID** box.
* Switch between grid view and list view using the view icons at the top right of the pane. Grid view shows the items as cards, and list view shows them as rows.
* Review each item's ID, name, short description, and price, exactly as a campaign displays them.
## Dropped Items
Dropped items are items that the model recommended but that have since been deleted from the catalog. When this happens, the preview shows an expandable notice telling you how many items are missing and listing the exact missing catalog item IDs.
To resolve dropped items, check that those IDs exist in an active feed, and that they match the attribute mapped as the item ID. This is the most direct way to find a catalog or event ID mismatch.
## Trending Items Configuration
For Trending Items recommendations, the test panel also displays the trend configuration in use, as described in the following table:
| Trend mode | What the panel displays |
| --------------- | --------------------------------------------------------------------- |
| Global trend | Global trend ranked by the ranking metric, for example, Best sellers. |
| Attribute trend | Attribute trend ranked by the attribute name, for example, Category. |
For attribute trends, the **By item** and **By attribute value** options appear only when you select **User Property** in the value drop-down list. If you select **Custom value** instead, only the standard trending options appear.
# Recommendation Conditions
The **Recommendation conditions** pane has two parts. **Generate Recommendation** shows the settings the model uses to produce results, and is read-only in the test panel. **Filter** lists every filter currently applied, and you can change these while you test.
MoEngage groups the filters under **User action**, **Exclude user action**, **Item attribute**, each marked AND or OR, and **Sort Recommendation**.
To see how a condition affects the results, perform the following steps:
1. Click the arrow next to a group to expand its individual conditions.
2. Select or clear the checkbox for a group or an individual condition. The preview on the right updates immediately.
3. Click **Reset changes** to revert everything to the saved configuration. This link becomes active only after you change something.
To find out why a particular item is missing from the results, turn conditions off one at a time until the item appears.
# Apply or Discard Filter Changes
After you finish testing, click **Done**. If you changed any conditions, MoEngage asks whether to apply the configuration to the recommendation, and warns that applying replaces the saved configuration.
1. Click **Apply filters** to save your test-time changes as the recommendation's new live configuration.
2. Click **Don't apply** to close the test view and keep the recommendation exactly as it was saved.
**Apply filters** overwrites the saved recommendation for everyone, not only for this test. If you are testing to diagnose a problem rather than to make a permanent change, click **Don't apply**.
# Troubleshoot Zero Results
A recommendation can return no results even when it is configured correctly, usually because of timing or a data mismatch. Check the following causes, in order:
1. **The interaction happened before you mapped the event.** MoEngage starts counting an event toward recommendations from the moment you save its user action mapping, and does not backfill anything from before that point. If your test user's only relevant activity predates the mapping, test again with more recent activity.
2. **The item ID in your interaction event does not match any item ID in your catalog.** Check that the attribute mapped as the item ID has identical values in both the event and the catalog feed, with the same casing, no extra spaces, and the same string or number format. This is the same mismatch that produces dropped items, but when every interacted item is mismatched you get zero results instead of a partial list.
3. **No user action is mapped yet for the model you are testing.** At least one of the four user actions must be mapped. [Map user actions](/docs/user-guide/content/recommendations/getting-started/map-user-actions-settings) before you test a User Actions model or an AI-personalized model.
4. **The test user no longer exists, or has been merged into another profile.** Test with the surviving MoEngage ID instead.
5. **You searched with an identifier type your account has no data for.** Confirm that the type you chose in the **Select user by** list actually has activity for this user.
6. **The catalog used by this recommendation was deleted.** [Reconnect a catalog](/docs/user-guide/content/recommendations/getting-started/catalogs) before you test again.
If none of these explain the result, contact [MoEngage Support](https://help.moengage.com/hc/en-us/requests/new) with the recommendation name and the identifier you tested with.
# Related Articles
* [Manage Recommendations](/docs/user-guide/content/recommendations/basic-recommendations/manage-basic-recommendations)
* [Creating Advanced Recommendations](/docs/user-guide/content/recommendations/advanced-recommendations/creating-advanced-recommendations)