> ## Documentation Index
> Fetch the complete documentation index at: https://wb-21fd5541-typedoc-upgrade.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Evaluation<R, E, M>

> TypeScript SDK reference

Defined in: [src/evaluation.ts:139](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/evaluation.ts#L139)

Sets up an evaluation which includes a set of scorers and a dataset.

Calling evaluation.evaluate(model) will pass in rows form a dataset into a model matching
the names of the columns of the dataset to the argument names in model.predict.

Then it will call all of the scorers and save the results in weave.

## Example

```ts twoslash theme={null}
// @noErrors
// Collect your examples into a dataset
const dataset = new weave.Dataset({
  id: 'my-dataset',
  rows: [
    { question: 'What is the capital of France?', expected: 'Paris' },
    { question: 'Who wrote "To Kill a Mockingbird"?', expected: 'Harper Lee' },
    { question: 'What is the square root of 64?', expected: '8' },
  ],
});

// Define any custom scoring function
const scoringFunction = weave.op(function isEqual({ modelOutput, datasetRow }) {
  return modelOutput == datasetRow.expected;
});

// Define the function to evaluate
const model = weave.op(async function alwaysParisModel({ question }) {
  return 'Paris';
});

// Start evaluating
const evaluation = new weave.Evaluation({
  id: 'my-evaluation',
  dataset: dataset,
  scorers: [scoringFunction],
});

const results = await evaluation.evaluate({ model });
```

## Extends

* [`WeaveObject`](./weaveobject)

## Type Parameters

### R

`R` *extends* `DatasetRow`

### E

`E` *extends* `DatasetRow`

### M

`M`

## Constructors

### Constructor

> **new Evaluation**\<`R`, `E`, `M`>(`parameters`): `Evaluation`\<`R`, `E`, `M`>

Defined in: [src/evaluation.ts:150](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/evaluation.ts#L150)

#### Parameters

##### parameters

`EvaluationParameters`\<`R`, `E`, `M`>

#### Returns

`Evaluation`\<`R`, `E`, `M`>

#### Overrides

[`WeaveObject`](./weaveobject).[`constructor`](./weaveobject#constructor)

## Properties

### \_\_savedRef?

> `optional` **\_\_savedRef?**: [`ObjectRef`](./objectref) | `Promise`\<[`ObjectRef`](./objectref)>

Defined in: [src/weaveObject.ts:71](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/weaveObject.ts#L71)

#### Inherited from

[`WeaveObject`](./weaveobject).[`__savedRef`](./weaveobject#__savedref)

## Accessors

### description

#### Get Signature

> **get** **description**(): `string` | `undefined`

Defined in: [src/weaveObject.ts:98](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/weaveObject.ts#L98)

##### Returns

`string` | `undefined`

#### Inherited from

[`WeaveObject`](./weaveobject).[`description`](./weaveobject#description)

***

### name

#### Get Signature

> **get** **name**(): `string`

Defined in: [src/weaveObject.ts:94](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/weaveObject.ts#L94)

##### Returns

`string`

#### Inherited from

[`WeaveObject`](./weaveobject).[`name`](./weaveobject#name)

## Methods

### evaluate()

> **evaluate**(`__namedParameters`): `Promise`\<`Record`\<`string`, `any`>>

Defined in: [src/evaluation.ts:165](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/evaluation.ts#L165)

#### Parameters

##### \_\_namedParameters

###### maxConcurrency?

`number` = `5`

###### model

`WeaveCallable`\<(...`args`) => `Promise`\<`M`>>

###### nTrials?

`number` = `1`

#### Returns

`Promise`\<`Record`\<`string`, `any`>>

***

### predictAndScore()

> **predictAndScore**(`__namedParameters`): `Promise`\<\{ `model_latency`: `number`; `model_output`: `any`; `model_success`: `boolean`; `scores`: \{\[`key`: `string`]: `any`; }; }>

Defined in: [src/evaluation.ts:244](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/evaluation.ts#L244)

#### Parameters

##### \_\_namedParameters

###### columnMapping?

`ColumnMapping`\<`R`, `E`>

###### example

`R`

###### model

`WeaveCallable`\<(...`args`) => `Promise`\<`M`>>

#### Returns

`Promise`\<\{ `model_latency`: `number`; `model_output`: `any`; `model_success`: `boolean`; `scores`: \{\[`key`: `string`]: `any`; }; }>

***

### saveAttrs()

> **saveAttrs**(): `object`

Defined in: [src/weaveObject.ts:75](https://github.com/wandb/weave/blob/8c5f077eb11c42b84000726ff20504abc728d3fb/sdks/node/src/weaveObject.ts#L75)

#### Returns

`object`

#### Inherited from

[`WeaveObject`](./weaveobject).[`saveAttrs`](./weaveobject#saveattrs)