Tip 2: Use structured outputs
Utilizing structured outputs means forcing the LLM to output legitimate JSON or YAML textual content. This can will let you scale back the ineffective ramblings and get “straight-to-the-point” solutions about what you want from the LLM. It additionally will assist with the following suggestions because it makes the LLM responses simpler to confirm.
Right here is how you are able to do this with Gemini’s API:
import jsonimport google.generativeai as genai
from pydantic import BaseModel, Discipline
from document_ai_agents.schema_utils import prepare_schema_for_gemini
class Reply(BaseModel):
reply: str = Discipline(..., description="Your Reply.")
mannequin = genai.GenerativeModel("gemini-1.5-flash-002")
answer_schema = prepare_schema_for_gemini(Reply)
query = "Listing all of the explanation why LLM hallucinate"
context = (
"LLM hallucination refers back to the phenomenon the place massive language fashions generate plausible-sounding however"
" factually incorrect or nonsensical data. This could happen because of varied elements, together with biases"
" within the coaching knowledge, the inherent limitations of the mannequin's understanding of the true world, and the "
"mannequin's tendency to prioritize fluency and coherence over accuracy."
)
messages = (
[context]
+ [
f"Answer this question: {question}",
]
+ [
f"Use this schema for your answer: {answer_schema}",
]
)
response = mannequin.generate_content(
messages,
generation_config={
"response_mime_type": "utility/json",
"response_schema": answer_schema,
"temperature": 0.0,
},
)
response = Reply(**json.masses(response.textual content))
print(f"{response.reply=}")
The place “prepare_schema_for_gemini” is a utility perform that prepares the schema to match Gemini’s bizarre necessities. You’ll find its definition right here: code.
This code defines a Pydantic schema and sends this schema as a part of the question within the subject “response_schema”. This forces the LLM to observe this schema in its response and makes it simpler to parse its output.
Tip 3: Use chain of ideas and higher prompting
Typically, giving the LLM the house to work out its response, earlier than committing to a remaining reply, will help produce higher high quality responses. This system is named Chain-of-thoughts and is extensively used as it’s efficient and really straightforward to implement.
We are able to additionally explicitly ask the LLM to reply with “N/A” if it might’t discover sufficient context to provide a top quality response. This can give it a straightforward approach out as a substitute of attempting to answer questions it has no reply to.
For instance, lets look into this easy query and context:
Context
Thomas Jefferson (April 13 [O.S. April 2], 1743 — July 4, 1826) was an American statesman, planter, diplomat, lawyer, architect, thinker, and Founding Father who served because the third president of america from 1801 to 1809.[6] He was the first creator of the Declaration of Independence. Following the American Revolutionary Conflict and earlier than turning into president in 1801, Jefferson was the nation’s first U.S. secretary of state below George Washington after which the nation’s second vice chairman below John Adams. Jefferson was a number one proponent of democracy, republicanism, and pure rights, and he produced formative paperwork and selections on the state, nationwide, and worldwide ranges. (Supply: Wikipedia)
Query
What 12 months did davis jefferson die?
A naive method yields:
Response
reply=’1826′
Which is clearly false as Jefferson Davis isn’t even talked about within the context in any respect. It was Thomas Jefferson that died in 1826.
If we modify the schema of the response to make use of chain-of-thoughts to:
class AnswerChainOfThoughts(BaseModel):
rationale: str = Discipline(
...,
description="Justification of your reply.",
)
reply: str = Discipline(
..., description="Your Reply. Reply with 'N/A' if reply isn't discovered"
)
We’re additionally including extra particulars about what we anticipate as output when the query isn’t answerable utilizing the context “Reply with ‘N/A’ if reply isn’t discovered”
With this new method, we get the next rationale (bear in mind, chain-of-thought):
The offered textual content discusses Thomas Jefferson, not Jefferson Davis. No details about the loss of life of Jefferson Davis is included.
And the ultimate reply:
reply=’N/A’
Nice ! However can we use a extra basic method to hallucination detection?
We are able to, with Brokers!
Tip 4: Use an Agentic method
We are going to construct a easy agent that implements a three-step course of:
- Step one is to incorporate the context and ask the query to the LLM with the intention to get the primary candidate response and the related context that it had used for its reply.
- The second step is to reformulate the query and the primary candidate response as a declarative assertion.
- The third step is to ask the LLM to confirm whether or not or not the related context entails the candidate response. It’s known as “Self-verification”: https://arxiv.org/pdf/2212.09561
As a way to implement this, we outline three nodes in LangGraph. The primary node will ask the query whereas together with the context, the second node will reformulate it utilizing the LLM and the third node will test the entailment of the assertion in relation to the enter context.
The primary node could be outlined as follows:
def answer_question(self, state: DocumentQAState):
logger.information(f"Responding to query '{state.query}'")
assert (
state.pages_as_base64_jpeg_images or state.pages_as_text
), "Enter textual content or pictures"
messages = (
[
{"mime_type": "image/jpeg", "data": base64_jpeg}
for base64_jpeg in state.pages_as_base64_jpeg_images
]
+ state.pages_as_text
+ [
f"Answer this question: {state.question}",
]
+ [
f"Use this schema for your answer: {self.answer_cot_schema}",
]
)response = self.mannequin.generate_content(
messages,
generation_config={
"response_mime_type": "utility/json",
"response_schema": self.answer_cot_schema,
"temperature": 0.0,
},
)
answer_cot = AnswerChainOfThoughts(**json.masses(response.textual content))
return {"answer_cot": answer_cot}
And the second as:
def reformulate_answer(self, state: DocumentQAState):
logger.information("Reformulating reply")
if state.answer_cot.reply == "N/A":
returnmessages = [
{
"role": "user",
"parts": [
{
"text": "Reformulate this question and its answer as a single assertion."
},
{"text": f"Question: {state.question}"},
{"text": f"Answer: {state.answer_cot.answer}"},
]
+ [
{
"text": f"Use this schema for your answer: {self.declarative_answer_schema}"
}
],
}
]
response = self.mannequin.generate_content(
messages,
generation_config={
"response_mime_type": "utility/json",
"response_schema": self.declarative_answer_schema,
"temperature": 0.0,
},
)
answer_reformulation = AnswerReformulation(**json.masses(response.textual content))
return {"answer_reformulation": answer_reformulation}
The third one as:
def verify_answer(self, state: DocumentQAState):
logger.information(f"Verifying reply '{state.answer_cot.reply}'")
if state.answer_cot.reply == "N/A":
return
messages = [
{
"role": "user",
"parts": [
{
"text": "Analyse the following context and the assertion and decide whether the context "
"entails the assertion or not."
},
{"text": f"Context: {state.answer_cot.relevant_context}"},
{
"text": f"Assertion: {state.answer_reformulation.declarative_answer}"
},
{
"text": f"Use this schema for your answer: {self.verification_cot_schema}. Be Factual."
},
],
}
]response = self.mannequin.generate_content(
messages,
generation_config={
"response_mime_type": "utility/json",
"response_schema": self.verification_cot_schema,
"temperature": 0.0,
},
)
verification_cot = VerificationChainOfThoughts(**json.masses(response.textual content))
return {"verification_cot": verification_cot}
Full code in https://github.com/CVxTz/document_ai_agents
Discover how every node makes use of its personal schema for structured output and its personal immediate. That is attainable because of the flexibility of each Gemini’s API and LangGraph.
Lets work by way of this code utilizing the identical instance as above ➡️
(Be aware: we aren’t utilizing chain-of-thought on the primary immediate in order that the verification will get triggered for our checks.)
Context
Thomas Jefferson (April 13 [O.S. April 2], 1743 — July 4, 1826) was an American statesman, planter, diplomat, lawyer, architect, thinker, and Founding Father who served because the third president of america from 1801 to 1809.[6] He was the first creator of the Declaration of Independence. Following the American Revolutionary Conflict and earlier than turning into president in 1801, Jefferson was the nation’s first U.S. secretary of state below George Washington after which the nation’s second vice chairman below John Adams. Jefferson was a number one proponent of democracy, republicanism, and pure rights, and he produced formative paperwork and selections on the state, nationwide, and worldwide ranges. (Supply: Wikipedia)
Query
What 12 months did davis jefferson die?
First node consequence (First reply):
relevant_context=’Thomas Jefferson (April 13 [O.S. April 2], 1743 — July 4, 1826) was an American statesman, planter, diplomat, lawyer, architect, thinker, and Founding Father who served because the third president of america from 1801 to 1809.’
reply=’1826′
Second node consequence (Reply Reformulation):
declarative_answer=’Davis Jefferson died in 1826′
Third node consequence (Verification):
rationale=’The context states that Thomas Jefferson died in 1826. The assertion states that Davis Jefferson died in 1826. The context doesn’t point out Davis Jefferson, solely Thomas Jefferson.’
entailment=’No’
So the verification step rejected (No entailment between the 2) the preliminary reply. We are able to now keep away from returning a hallucination to the consumer.
Bonus Tip : Use stronger fashions
This tip isn’t all the time straightforward to use because of finances or latency limitations however you need to know that stronger LLMs are much less susceptible to hallucination. So, if attainable, go for a extra highly effective LLM to your most delicate use instances. You’ll be able to test a benchmark of hallucinations right here: https://github.com/vectara/hallucination-leaderboard. We are able to see that the highest fashions on this benchmark (least hallucinations) additionally ranks on the prime of typical NLP chief boards.
On this tutorial, we explored methods to enhance the reliability of LLM outputs by decreasing the hallucination fee. The primary suggestions embrace cautious formatting and prompting to information LLM calls and utilizing a workflow primarily based method the place Brokers are designed to confirm their very own solutions.
This entails a number of steps:
- Retrieving the precise context parts utilized by the LLM to generate the reply.
- Reformulating the reply for simpler verification (In declarative kind).
- Instructing the LLM to test for consistency between the context and the reformulated reply.
Whereas all the following tips can considerably enhance accuracy, you need to keep in mind that no methodology is foolproof. There’s all the time a threat of rejecting legitimate solutions if the LLM is overly conservative throughout verification or lacking actual hallucination instances. Due to this fact, rigorous analysis of your particular LLM workflows remains to be important.
Full code in https://github.com/CVxTz/document_ai_agents
