# Assessment Item Observations — Secondary-Measure Weighted Mean + Explicit Missing-Value Fill

> Assessment Item Observations — Secondary-Measure Weighted Mean + Explicit Missing-Value Fill is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-23).

Computes a secondary-measure weighted mean and fills missing values in assessment item observation records (correct_responses, attempts) for up to 200 rows, returning 2 analytical reports.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-ib26-education-02-187?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/assessment-item-observations-secondary-measure-weighted-mean-explicit-98861134
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iGBiUg6rGQs9Uoh-DKzFN

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability assessment-item-observations-secondary-measure-weighted-mean-explicit-98861134 -d '<json body>'
```

Example prompt: Can you compute the weighted mean of correct_responses for my assessment item data and fill any missing values using median imputation? I have 4 rows across two course groups (group-a and group-b) with dates from 2026-10-01 to 2026-10-04 and attempt counts of 1 through 4.

## When to prefer this

Choose this endpoint when you have tabular assessment item observation data (correct_responses and attempts) that needs both missing-value imputation and a weighted mean computation in a single call, without any external data lookup or prediction. Best suited for offline batch analysis of up to 200 rows of education/quiz data where you want two self-contained analytical reports at low cost.

## Known failure modes

- More than 200 rows submitted — request rejected with validation error
- Missing required fields (row_id, course_group, date, correct_responses, attempts) — row rejected
- Invalid date format (not YYYY-MM-DD) — schema validation failure
- Empty rows array — minimum item count not met
- Invalid enum value for field or method — schema validation error
- Numeric values outside allowed range — rejected by schema constraints

## How this service works

Assessment item observations — Secondary-measure weighted mean + Explicit missing-value fill: Secondary-measure weighted mean + Explicit missing-value fill for supplied assessment item observations records (correct_responses, attempts). Up to 200 rows; 2 independent reports using shared local analytical engines. No live lookup, prediction, professional assessment or external action. 0.01 USDC includes 2 supplied-data reports for up to 200 rows.

## Output

Two analytical reports covering: (1) secondary-measure weighted mean of the selected field (correct_responses or attempts) and (2) explicit missing-value fill results using the chosen method (zero, mean, or median), applied to up to 200 supplied assessment item observation rows.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "rows": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "row_id",
     "course_group",
     "date",
     "correct_responses",
     "attempts"
    ],
    "properties": {
     "date": {
      "type": "string",
      "default": "",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
      "maxLength": 10
     },
     "row_id": {
      "type": "string",
      "default": "",
      "maxLength": 80,
      "minLength": 1
     },
     "attempts": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     },
     "course_group": {
      "type": "string",
      "default": "",
      "maxLength": 80
     },
     "correct_responses": {
      "type": [
       "number",
       "null"
      ],
      "maximum": 1000000000000,
      "minimum": -1000000000000
     }
    },
    "additionalProperties": false
   },
   "default": [
    {
     "date": "2026-10-01",
     "row_id": "row-1",
     "attempts": 1,
     "course_group": "group-a",
     "correct_responses": 10
    },
    {
     "date": "2026-10-02",
     "row_id": "row-2",
     "attempts": 2,
     "course_group": "group-b",
     "correct_responses": 20
    },
    {
     "date": "2026-10-03",
     "row_id": "row-3",
     "attempts": 3,
     "course_group": "group-a",
     "correct_responses": 15
    },
    {
     "date": "2026-10-04",
     "row_id": "row-4",
     "attempts": 4,
     "course_group": "group-b",
     "correct_responses": 30
    }
   ],
   "maxItems": 200,
   "minItems": 1
  },
  "field": {
   "enum": [
    "correct_responses",
    "attempts"
   ],
   "type": "string",
   "default": "correct_responses"
  },
  "method": {
   "enum": [
    "zero",
    "mean",
    "median"
   ],
   "type": "string",
   "default": "median"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/assessment-item-observations-secondary-measure-weighted-mean-explicit-98861134/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)