Get Measure Using Scale Score with Prior Student Information

Overview

This Bayesian function should be used when:

There is prior information about a student. For example, a previously-computed priorAbility with priorUncertainty and number of days since that assessment elapsedDays.
The student has taken a linked test with a known link ID.
The student’s scale score and standard error (or conditional standard error) are being provided.

URL

POST /api/score/scale/bayes

Request

The following parameters are required in the request. An example is provided in the Code Example section.


Parameter	Type	Description
`linkId`	String	ID associated with the linking table for the external test. MetaMetrics will provide these IDs.
`scaleScore`	String	The scale score received on the external test.
`scaleSem`	Integer	The standard error of measurement (or conditional sem) received on the external test.
`priorAbility`	Integer	The student’s prior ability estimate.
`priorUncertainty`	Integer	Uncertainty associated with the student’s prior ability estimate.
`elapsedDays`	Integer	Number of days since the student’s measure was last updated.

Response

This returns an object that contains the computed ability and uncertainty. See Scoring Service Response Codes for an explanation of error codes that might be returned.


Parameter	Type	Description
`ability`	Integer	The student’s new ability estimate.
`uncertainty`	Integer	Uncertainty associated with the student’s new ability estimate.
`framework`	String	Either Lexile or Quantile; framework used to produce the measure.
`apiVersion`	String	The current version number for the API.

Code Examples

The following show examples of the request followed by the response. The Python example is written for use with Python 3 and above.

import java.io.BufferedReader;
                   import java.io.IOException;
                   import java.io.InputStreamReader;
                   import java.util.HashMap;
                   import java.util.List;
                   import java.util.ArrayList;
                   import java.util.Arrays;
                   import java.util.Map;
                   import org.apache.http.HttpHeaders;
                   import org.apache.http.HttpResponse;
                   import org.apache.http.client.HttpClient;
                   import org.apache.http.client.methods.HttpPost;
                   import org.apache.http.entity.StringEntity;
                   import org.apache.http.impl.client.HttpClientBuilder;
                   
                   import org.json.JSONObject;
                   
                   
                   public class BayesScaleScore {
                   public static void main( String[] args )
                   {
                   try
                   {
                   // Call 9
                   
                   String baseURL = "https://scoring.lexile.com";
                   String clientId = "your_client_id";
                   String clientSecret = "your_client_secret";
                   
                   HttpClient client = HttpClientBuilder.create().build();
                   HttpPost authPost = new HttpPost(baseURL + "/authToken");
                   JSONObject jsonInput = new JSONObject();
                   jsonInput.put("clientId", clientId);
                   jsonInput.put("clientSecret", clientSecret);
                   StringEntity input = new StringEntity(jsonInput.toString());
                   authPost.setEntity(input);
                   authPost.setHeader(HttpHeaders.CONTENT_TYPE, "application/json");
                   HttpResponse response = client.execute(authPost); 
                   StringBuilder stringBuilder = new StringBuilder();
                   BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
                   String line;
                   while ((line = rd.readLine()) != null) 
                   {
                   stringBuilder.append(line);
                   }
                   JSONObject json = new JSONObject(stringBuilder.toString());
                   String token = (String) json.get("accessToken");
                   Integer expires = (Integer) json.get("expiresIn");
                   
                   
                   // 1) Basic Example
                   
                   HttpPost postScaleScore = new HttpPost(baseURL + "/api/score/scale/bayes");
                   JSONObject postData = new JSONObject();
                   postData.put("linkId", "mNxV");
                   postData.put("scaleScore", "1");
                   postData.put("scaleSem", 20);
                   postData.put("priorAbility", 200);
                   postData.put("priorUncertainty", 50);
                   postData.put("elapsedDays", 20);
                   
                   StringEntity formInput = new StringEntity(postData.toString());
                   postScaleScore.setEntity(formInput);
                   postScaleScore.setHeader(HttpHeaders.AUTHORIZATION, "Bearer " + token);
                   postScaleScore.setHeader(HttpHeaders.CONTENT_TYPE, "application/json");
                   response = client.execute(postScaleScore); 
                   stringBuilder = new StringBuilder();
                   rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
                   while ((line = rd.readLine()) != null) 
                   {
                   stringBuilder.append(line);
                   }
                   JSONObject output = new JSONObject(stringBuilder.toString());
                   Integer ability = (Integer) output.get("ability");
                   Integer uncertainty = (Integer) output.get("uncertainty");
                   String framework = (String) output.get("framework");
                   String apiVersion = (String) output.get("apiVersion");
                   }
                   catch(IOException e) 
                   {
                   e.printStackTrace();
                   }
                   }
                   }
                   
                   //System.out.println(stringBuilder.toString());

# Call 9
                       
                       # /authToken
                       
                       import requests
                       import json
                       
                       base_url = "https://scoring.lexile.com"
                       client_id = "your_client_id"  # replace with your provided client ID
                       client_secret = "your_client_secret"  # replace with your provided client secret
                       response = requests.post(
                       f"{base_url}/authToken",
                       data={"clientId": client_id, "clientSecret": client_secret},
                       )
                       access_token = response.json()["accessToken"]  # use in Authorization header
                       
                       # use these headers to make requests
                       headers = {
                       "Authorization": f"Bearer {access_token}",
                       "Content-Type": "application/json",
                       }
                       
                       
                       # /api/score/scale/bayes
                       
                       # 1) Basic Example
                       data = {
                       "priorAbility": 500,
                       "priorUncertainty": 100,
                       "elapsedDays": 15,
                       "linkId": "mNxV",
                       "scaleScore": "5",
                       "scaleSem": 10,
                       }
                       response = requests.post(
                       f"{base_url}/api/score/scale/bayes", headers=headers, json=data
                       )
                       response.json()
                       # returns
                       # {
                       #    "ability": <int>,
                       #    "uncertainty": <int>
                       #    "framework": ["lexile" or "quantile"]
                       #    "apiVersion": <string>
                       # }