Tracking progress on revamping documentation pages for the refactor of LM-Evaluation-Harness.
# Eval Harness Documentation
Welcome to the docs for the LM Evaluation Harness!
## Table of Contents
* To learn how to add a new library, API, or model type to the library, as well as a quick explainer on the types of ways to evaluate an LM, see the [Model Guide](https://github.com/EleutherAI/lm-evaluation-harness/blob/big-refactor/docs/model_guide.md).
* For a crash course on adding new tasks to the library, see our [New Task Guide](https://github.com/EleutherAI/lm-evaluation-harness/blob/big-refactor/docs/new_task_guide.md).
* To learn more about pushing the limits of task configuration that the Eval Harness supports, see the [Advanced Task Guide](https://github.com/EleutherAI/lm-evaluation-harness/blob/big-refactor/docs/advanced_task_guide.md).
## Progress on Revamp
Tracking progress on revamping documentation pages for the refactor of LM-Evaluation-Harness.
The `lm-evaluation-harness` is intended to be a model-agnostic framework for evaluating . We provide first-class support for HuggingFace `AutoModelForCausalLM` and `AutoModelForSeq2SeqLM` type models, but
This guide may be of special interest to users who are using the library outside of the repository, via installing the library via pypi and calling `lm_eval.evaluator.evaluate()` to evaluate an existing model.
In order to properly evaluate a given LM, we require implementation of a wrapper class subclassing the `lm_eval.api.model.LM` class, that defines how the Evaluation Harness should interface with your model. This guide walks through how to write this `LM` subclass via adding it to the library!
## Setup
To get started contributing, go ahead and fork the main repo, clone it, create a branch with the name of your task, and install the project requirements in your environment:
Now, we'll create a new file where we'll be adding our model:
```sh
touch lm_eval/models/<my_model_filename>.py
```
**Tip: this filename should not shadow package names! For example, naming your file `anthropic.py` is disallowed since the API's name on pypi is `anthropic`, but naming it `anthropic_llms.py` works with no problems.**
## Interface
All models must subclass the `lm_eval.api.model.LM` class.
The LM class enforces a common interface via which we can extract responses from a model:
```python
classMyCustomLM(LM):
#...
defloglikelihood(self,requests):
defloglikelihood_rolling(self,requests):
defgreedy_until(self,requests):
#...
```
We support
The three types of
smth smth tokenizer-agnostic
3 reqtypes
- greedy_until, and the arguments passed to it
- loglikelihood, and args passed to it
- loglikelihood_rolling, and args passed to it
## Registration
Congrats on implementing your model! Now it's time to test it out.
To make your model usable via the command line interface to `lm-eval` using `main.py`, you'll need to tell `lm-eval` what your model's name is.
This is done via a *decorator*, `lm_eval.api.registry.register_model`. Using `register_model()`, one can both tell the package what the model's name(s) to be used are when invoking it with `python main.py --model <name>` and alert `lm-eval` to the model's existence.
```python
fromlm_eval.api.registryimportregister_model
@register_model("<name1>","<name2>")
classMyCustomLM(LM):
```
Using this decorator results in the class being added to an accounting of the usable LM types maintained internally to the library at `lm_eval.api.registry.MODEL_REGISTRY`. See `lm_eval.api.registry` for more detail on what sorts of registries and decorators exist in the library!
## Other
**Pro tip**: In order to make the Evaluation Harness overestimate total runtimes rather than underestimate it, HuggingFace models come in-built with the ability to provide responses on data points in *descending order by total input length* via `lm_eval.utils.Reorderer`. Take a look at `lm_eval.models.hf_causal.HFLM` to see how this is done, and see if you can implement it in your own model!
## Conclusion
After reading this guide, you should be able to add new model APIs or implementations to the Eval Harness library!
@@ -85,13 +85,31 @@ Such that {{question}} will be replaced by `doc["question"]` when rendering the
Our intended output is for the model to predict a single whitespace, and then the answer to the question. We do this via:
```yaml
doc_to_target:"{{answer}}"
gold_alias:"{{answer}}"
```
where `doc_to_target` is *the string that will be appended to inputs for each few-shot example*, and `gold_alias` is *what is passed to our metric function as reference or gold answer to score against*. For example, for GSM8k word problems, `doc_to_target` should be the reference text reasoning chain given in the dataset culminating in the answer, and `gold_alias` should be **only the numeric answer** to the word problem that is given at the end of the reasoning chain, and which the evaluated model's answer will be compared against.
**Important**: We always add one whitespace between the input and output, such that the full input-output string is `doc_to_target(doc) + " " + doc_to_text(doc)`. doc_to_text and doc_to_target should not contain trailing right or left whitespace, respectively.
Users can also fill out the optional `template_aliases` YAML field, which is added ahead of both the `doc_to_text` and `doc_to_target` fields. This field should not contain any test, but only Jinja variable definitions (`{% ... %}` clauses). This can be used to perform more involved string manipulations and renamings of dataset columns while the main prompt fields remain easy to parse visually.
#### Multiple choice format
For tasks which are multiple choice (a fixed, finite set of label words per each document) and evaluated via comparing loglikelihoods of all label words (the `multiple_choice` task output type) we enforce a particular convention on prompt format.
An annotated example in the case of SciQ is as follows:
```yaml
template_aliases:"{%setanswer_choices=[distractor1,distractor2,distractor3,correct_answer]%}{%setgold=3%}"# `template_aliases` must set the list of possible answer choices to the jinja variable `answer_choices` (List[str]), and set what the index within `answer_choices` of this doc's gold label (correct answer choice).
doc_to_text:"{{support.lstrip()}}\nQuestion:{{question}}\nAnswer:"# This is the input portion of the prompt for this doc. It will have " {{choice}}" appended to it as target for each choice in answer_choices.
doc_to_target:"{{answer_choices[gold]}}"# this contains the gold-standard answer choice, selected via indexing to index `gold` in the answer choice list.
gold_alias:"{{gold}}"# this must be castable to an integer. It must output only the index within `answer_choices` that is the correct label.
```
Task implementers are thus able to decide what the answer choices should be for a document, and what prompt format to use.
### Using Python Functions for Prompts
There may be cases where the prompt we want to implement is easier expressed in Python instead of Jinja 2. For this, we can use Python helper functions that are defined in the YAML config. It should be noted that the function script must be in the same directory as the yaml.
For tasks which are multiple choice (a fixed, finite set of label words per each document) and evaluated via comparing loglikelihoods of all label words (the `multiple_choice` task output type) we enforce a particular convention on prompt format.
An annotated example in the case of SciQ is as follows:
```yaml
template_aliases:"{%setanswer_choices=[distractor1,distractor2,distractor3,correct_answer]%}{%setgold=3%}"# `template_aliases` must set the list of possible answer choices to the jinja variable `answer_choices` (List[str]), and set what the index within `answer_choices` of this doc's gold label (correct answer choice).
doc_to_text:"{{support.lstrip()}}\nQuestion:{{question}}\nAnswer:"# This is the input portion of the prompt for this doc. It will have " {{choice}}" appended to it as target for each choice in answer_choices.
doc_to_target:"{{gold}}"# this must be castable to an integer. It must output only the index within `answer_choices` that is the correct label.
```
Task implementers are thus able to decide what the answer choices should be for a document, and what prompt format to use.
### Setting metrics
You're almost done! Now we need to choose how to score our task.
template_aliases:"{%setanswer_choices=choices['text']%}{%setgold=choices.label.index(answerKey)%}"# set the list of possible answer choices, and set what this doc's gold answer is (set what ds column used, and what)
doc_to_text:"Question:{{question}}\nAnswer:"
doc_to_target:"{{gold}}"# this will be cast to an int.
doc_to_target:"{{answer_choices[gold]}}"
gold_alias:"{{gold}}"# this will be cast to an int.
template_aliases:"{%setanswer_choices=choices['text']%}{%setgold=choices.label.index(answerKey)%}"# set the list of possible answer choices, and set what this doc's gold answer is (set what ds column used, and what)
doc_to_text:"Question:{{question}}\nAnswer:"
doc_to_target:"{{gold}}"# this will be cast to an int.
doc_to_target:"{{answer_choices[gold]}}"
gold_alias:"{{gold}}"# this will be cast to an int.
template_aliases:"{%setquestion=goal%}{%setanswer_choices=[sol1,sol2]%}{%setgold=label%}"# set the list of possible answer choices, and set what this doc's gold label idx is
doc_to_text:"Question:{{question}}\nAnswer:"
doc_to_target:"{{gold}}"# this will be cast to an int.
doc_to_target:"{{answer_choices[gold]}}"
gold_alias:"{{gold}}"# this will be cast to an int.
template_aliases:"{%setanswer_choices=[distractor1,distractor2,distractor3,correct_answer]%}{%setgold=3%}"# set the list of possible answer choices, and set what this doc's gold label idx is
