# Safety and factuality guidance

Generative artificial intelligence models are powerful tools, but they are not
without their limitations. Their versatility and applicability can sometimes
lead to unexpected outputs, such as outputs that are inaccurate, biased, or
offensive. Post-processing, and rigorous manual evaluation are essential to
limit the risk of harm from such outputs.

The models provided by the Gemini API can be used for a wide variety of
generative AI and natural language processing (NLP) applications. Use of these
functions is only available through the Gemini API or the Google AI Studio web
app. Your use of Gemini API is also subject to the [Generative AI Prohibited Use
Policy](https://policies.google.com/terms/generative-ai/use-policy) and the
[Gemini API terms of service](https://ai.google.dev/terms).

Part of what makes large language models (LLMs) so useful is that they're
creative tools that can address many different language tasks. Unfortunately,
this also means that large language models can generate output that you don't
expect, including text that's offensive, insensitive, or factually incorrect.
What's more, the incredible versatility of these models is also what makes it difficult to
predict exactly what kinds of undesirable output they might produce. While the
Gemini API has been designed with [Google's AI
principles](https://ai.google/principles/) in mind, the onus is on developers to
apply these models responsibly. To aid developers in creating safe, responsible
applications, the Gemini API has some built-in content filtering as well as
adjustable safety settings across 4 dimensions of harm. Refer to the
[safety settings](https://ai.google.dev/gemini-api/docs/safety-settings) guide to learn more. It also offers Grounding
with Google Search enabled to improve factuality, though this may be disabled
for developers whose use cases are more creative and not information-seeking.

This document is meant to introduce you to some safety risks that can arise when
using LLMs, and recommend emerging safety design and development
recommendations. (Note that laws and regulations may also impose restrictions,
but such considerations are beyond the scope of this guide.)

The following steps are recommended when building applications with LLMs:

- Understanding the safety risks of your application
- Considering adjustments to mitigate safety risks
- Performing safety testing appropriate to your use case
- Soliciting feedback from users and monitoring usage

The adjustment and testing phases should be iterative until you reach
performance appropriate for your application.

![Model implementation cycle](https://ai.google.dev/static/gemini-api/docs/images/safety_diagram.png)

## Understand the safety risks of your application

In this context, safety is being defined as the ability of an LLM to avoid
causing harm to its users, for example, by generating toxic language or content
that promotes stereotypes. The models available through the Gemini API have been
designed with [Google's AI principles](https://ai.google/principles/) in mind
and your use of it is subject to the [Generative AI Prohibited Use
Policy](https://policies.google.com/terms/generative-ai/use-policy). The API
provides built-in safety filters to help address some common language model
problems such as toxic language and hate speech, and striving for inclusiveness
and avoidance of stereotypes. However, each application can pose a different set
of risks to its users. So as the application owner, you are responsible for
knowing your users and the potential harms your application may cause, and
ensuring that your application uses LLMs safely and responsibly.

As part of this assessment, you should consider the likelihood that harm could
occur and determine its seriousness and mitigation steps. For example, an
app that generates essays based on factual events would need to be more careful
about avoiding misinformation, as compared to an app that generates fictional
stories for entertainment. A good way to begin exploring potential safety risks
is to research your end users, and others who might be affected by your
application's results. This can take many forms including researching state of
the art studies in your app domain, observing how people are using similar apps,
or running a user study, survey, or conducting informal interviews with
potential users.

### Advanced tips

- Speak with a diverse mix of prospective users within your target population about your application and its intended purpose so as to get a wider perspective on potential risks and to adjust diversity criteria as needed.
- The [AI Risk Management Framework](https://www.nist.gov/itl/ai-risk-management-framework) released by the U.S. government's National Institute of Standards and Technology (NIST) provides more detailed guidance and additional learning resources for AI risk management.
- DeepMind's publication on the [ethical and social risks of harm from language models](https://arxiv.org/abs/2112.04359) describes in detail the ways that language model applications can cause harm.

## Consider adjustments to mitigate safety and factuality risks

Now that you have an understanding of the risks, you can decide how to mitigate
them. Determining which risks to prioritize and how much you should do to try to
prevent them is a critical decision, similar to triaging bugs in a software
project. Once you've determined priorities, you can start thinking about the
types of mitigations that would be most appropriate. Often simple changes can
make a difference and reduce risks.

For example, when designing an application consider:

- **Tuning the model output** to better reflect what is acceptable in your application context. Tuning can make the output of the model more predictable and consistent and therefore can help mitigate certain risks.
- **Providing an input method that facilities safer outputs.** The exact input you give to an LLM can make a difference in the quality of the output. Experimenting with input prompts to find what works most safely in your use-case is well worth the effort, as you can then provide a UX that facilitates it. For example, you could restrict users to choose only from a drop-down list of input prompts, or offer pop-up suggestions with descriptive phrases which you've found perform safely in your application context.
- **Blocking unsafe inputs and filtering output before it is shown to the
  user.** In simple situations, blocklists can be used to identify and block
  unsafe words or phrases in prompts or responses, or require human reviewers
  to manually alter or block such content.

  > [!NOTE]
  > **Note:** Automatically blocking based on a static list can have unintended results such as targeting a particular group that commonly uses vocabulary in the blocklist.

- **Using trained classifiers to label each prompt with potential harms or
  adversarial signals.** Different strategies can then be employed on how to
  handle the request based on the type of harm detected. For example, If the
  input is overtly adversarial or abusive in nature, it could be blocked and
  instead output a pre-scripted response.
  **Advanced tip:** If signals determine the output to be harmful, the
  application can employ the following options:

  - Provide an error message or pre-scripted output.
  - Try the prompt again, in case an alternative safe output is generated, since sometimes the same prompt will elicit different outputs.
- **Putting safeguards in place against deliberate misuse** such as assigning
  each user a unique ID and imposing a limit on the volume of user queries
  that can be submitted in a given period. Another safeguard is to try and
  protect against possible prompt injection. Prompt injection, much like SQL
  injection, is a way for malicious users to design an input prompt that
  manipulates the output of the model, for example, by sending an input prompt
  that instructs the model to ignore any previous examples. See the
  [Generative AI Prohibited Use Policy](https://policies.google.com/terms/generative-ai/use-policy)
  for details about deliberate misuse.

- **Adjusting functionality to something that is inherently lower risk.**
  Tasks that are narrower in scope (e.g., extracting keywords from passages of
  text) or that have greater human oversight (e.g., generating short-form
  content that will be reviewed by a human), often pose a lower risk. So for
  instance, instead of creating an application to write an email reply from
  scratch, you might instead limit it to expanding on an outline or suggesting
  alternative phrasings.

- **Adjusting harmful content safety settings to decrease how likely you are to
  see responses that could be harmful.** The Gemini API provides safety settings
  that you can adjust during the prototyping stage to determine if your
  application requires more or less restrictive safety configuration. You can
  adjust these settings across five filter categories to restrict or allow
  certain types of content. Refer to the [safety settings guide](https://ai.google.dev/gemini-api/docs/safety-settings) to learn about
  the adjustable safety settings available through the Gemini API.

- **Decrease potential factual inaccuracies or hallucinations by enabling
  Grounding with Google Search**. Remember, many AI models are experimental
  and may present factually inaccurate information, hallucinate, or otherwise
  produce problematic outputs. The Grounding with Google Search feature connects
  the Gemini model to real-time web content and works with all available
  languages. This allows Gemini to provide more accurate answers and cite
  verifiable sources beyond the models knowledge cutoff.

## Perform safety testing appropriate to your use case

Testing is a key part of building robust and safe applications, but the extent,
scope and strategies for testing will vary. For example, a just-for-fun haiku
generator is likely to pose less severe risks than, say, an application designed
for use by law firms to summarize legal documents and help draft contracts. But
the haiku generator may be used by a wider variety of users which means the
potential for adversarial attempts or even unintended harmful inputs can be
greater. The implementation context also matters. For instance, an application
with outputs that are reviewed by human experts prior to any action being taken
might be deemed less likely to produce harmful outputs than the identical
application without such oversight.

It's not uncommon to go through several iterations of making changes and testing
before feeling confident that you're ready to launch, even for applications that
are relatively low risk. Two kinds of testing are particularly useful for AI
applications:

- **Safety benchmarking** involves designing safety metrics that reflect the
  ways your application could be unsafe in the context of how it is likely to
  get used, then testing how well your application performs on the metrics
  using evaluation datasets. It's good practice to think about the minimum
  acceptable levels of safety metrics before testing so that 1) you can
  evaluate the test results against those expectations and 2) you can gather
  the evaluation dataset based on the tests that evaluate the metrics you care
  about most.

  **Advanced tips:**
  - Beware of over-relying on "off the shelf" approaches as it's likely you'll need to build your own testing datasets using human raters to fully suit your application's context.
  - If you have more than one metric you'll need to decide how you'll trade off if a change leads to improvements for one metric to the detriment of another. Like with other performance engineering, you may want to focus on worst-case performance across your evaluation set rather than average performance.
- **Adversarial testing** involves proactively trying to break your
  application. The goal is to identify points of weakness so that you can take
  steps to remedy them as appropriate. Adversarial testing can take
  significant time/effort from evaluators with expertise in your application ---
  but the more you do, the greater your chance of spotting problems,
  especially those occurring rarely or only after repeated runs of the
  application.

  - Adversarial testing is a method for systematically evaluating an ML model with the intent of learning how it behaves when provided with malicious or inadvertently harmful input:
    - An input may be malicious when the input is clearly designed to produce an unsafe or harmful output-- for example, asking a text generation model to generate a hateful rant about a particular religion.
    - An input is inadvertently harmful when the input itself may be innocuous, but produces harmful output -- for example, asking a text generation model to describe a person of a particular ethnicity and receiving a racist output.
  - What distinguishes an adversarial test from a standard evaluation is the
    composition of the data used for testing. For adversarial tests, select
    test data that is most likely to elicit problematic output from
    the model. This means probing the model's behavior for all the types of
    harms that are possible, including rare or unusual examples and
    edge-cases that are relevant to safety policies. It should also include
    diversity in the different dimensions of a sentence such as structure,
    meaning and length. You can refer to the [Google's Responsible AI
    practices in
    fairness](https://ai.google/responsibilities/responsible-ai-practices/?category=fairness)
    for more details on what to consider when building a test dataset.
    **Advanced tips:**

  - Use [automated testing](https://www.deepmind.com/blog/red-teaming-language-models-with-language-models)
    instead of the traditional method of enlisting people in 'red
    teams' to try and break your application. In automated testing,
    the 'red team' is another language model that finds input text
    that elicit harmful outputs from the model being tested.

  > [!NOTE]
  > **Note:** LLMs are known to sometimes produce different outputs for the same input prompt. Multiple rounds of testing may be needed to catch more of the problematic outputs.

## Monitor for problems

No matter how much you test and mitigate, you can never guarantee perfection, so
plan upfront how you'll spot and deal with problems that arise. Common
approaches include setting up a monitored channel for users to share feedback
(e.g., thumbs up/down rating) and running a user study to proactively solicit
feedback from a diverse mix of users --- especially valuable if usage patterns are
different to expectations.

### Advanced tips

- When users give feedback to AI products, it can greatly improve the AI performance and the user experience over time by, for example, helping you choose better examples for prompt tuning. The [Feedback and Control chapter](https://pair.withgoogle.com/chapter/feedback-controls/) in [Google's People and AI guidebook](https://pair.withgoogle.com/guidebook/chapters) highlights key considerations to take into account when designing feedback mechanisms.

## Next steps

- Refer to the [safety settings](https://ai.google.dev/gemini-api/docs/safety-settings) guide to learn about the adjustable safety settings available through the Gemini API.
- See the [intro to prompting](https://ai.google.dev/gemini-api/docs/prompting-intro) to get started writing your first prompts.