By Romeo Kienzler, Chief Data Scientist, IBM Center for Open Source Data and AI Technologies
We’re currently in the process of integrating the Trusted AI Toolkits into Acumos AI. There are of course many possibilities in doing so – therefore we’ve started the journey with an architecture development method. Maybe not many of you are familiar with TOGAF – The Open Group Architecture Framework – but we’re making use of it here in order to make sure the architectural choices of integrating the Trusted AI Toolkits are sound. As you can see below in Figure 1, the development of an architecture is an iterative process. Since we’ve completed one iteration, we want to give you an update on the actual development of those individual process steps.
It is agreed by many AI practitioners that Trusted AI is a key property for large scale adoption of AI into enterprise. A set of questions illustrated in Figure 2, taken from Todd Moore’s (IBM VP, Open Technology) keynote at the Linux Foundation Conference in Lyon 2019 needs to be asked about every AI model apart from it’s generic performance metrics like accuracy, F1 score or area under ROC.
Since open source toolkits exist within the Linux Foundation AI to answer these questions, the task is to find out, how they are used most efficiently.
To answer the questions above the following checks and mitigations against an AI model deployment candidate must be done:
- Adversarial Robustness Assessment and Mitigation
- Bias Detection and Mitigation
- Accountability (Repeatability / Data and Model Lineage)
A set of open source tools exist for each of those tasks. In the following we want to make sure to identify the correct tools and the correct ways of integrating them to maximize their positive impact. So the overall value proposition of this architecture is the removal of
major road blocks of brining AI models into production, by generating, qualifying and quantifying trust, affecting Stakeholders like Regulators, Auditors and Business Representatives. Ease of use and adoption rate are the main drivers for transformation and can be seen as the main KPIs here.
Therefore, the main risk is complexity. The higher the complexity, the more adoption rate declines.
Information Systems Architecture
In this current iteration we only focus on bias detection using the AIF360 toolkit. Bias mitigation, adversarial robustness, explainability and accountability will be covered in future versions of this document. Although such a component can be deployed in many ways in an abundance of different possible information systems architectures, we’ve identified only two different generic integrations scenarios, which we call data driven integration and model driven integration.
Data driven integration
In data driven integration the AI model is only taking part in such that it generates predictions which are stored to a database. Using the model’s predictions and the ground truth, bias metrics can be computed. This works exactly in the same way ordinary model validation is done on a test set which hasn’t been used for training the model. The test set is applied to the model and then it’s performance is assessed on the predictions generated by the model on the test set using a metric algorithm. So the same rule applies here, but instead of an ordinary metric algorithm, the algorithms for bias measurement are used. This process is illustrated in Figure 3.
Model driven integration
On the other hand, a second integration scenario might be feasible as well which we call “model driven integration”. In this case, no data is provided to the bias detection library, only the model and a configuration object which contains information on the protected attributes, the label columns and the schema. In this case, the model has to be executed in an appropriate runtime first using artificial data. If this is a feasible way of integration will be determined during the next iterations of this project. Figure 4 illustrates this.
Since model driven integration is not yet confirmed to work, we propose finally a hybrid integration, as illustrated in Figure 5, where the model is executed in an appropriate environment but has access to the test data set. This is very similar to the data driven approach which the difference that model predictions are not needed beforehand but are created on the fly during execution of the validation process. This might have advantages in the area of data lineage / accountability or facilitating operational aspects.
Among others, integration into Acumos AI is one of the most important aspects of this project. Although other integration points exist, we first started with an evaluation of integration into Apache Nifi since Nifi will be part of the next release of Acumos AI and play a central role in data integration tasks. Therefore, a POC was conducted on integration the LF AI AIF360 (AI Fairness 360) toolkit as a custom processor into Apache Nifi using the data driven approach.
Opportunities and Solutions
For simplicity we started with the ExecuteStreamCommand Processor within Nifi which allows wrapping any executable which reads from STDIN and writes to STDOUT into a Nifi Processor.
We’ve used an Ubuntu 18.04 Server LTS system and installed Apache Nifi on top of it. The following script installs Apache Nifi and takes care of the necessary configuration:
apt install -y openjdk-8-jdk unzip git
apt install -y python3-pip
pip3 install –upgrade pip
apt install -y python3-venv
python3 -m venv venv
pip3 install aif360
git clone https://github.com/romeokienzler/lfai_nifi.git
Now it’s time to test. In a browser, Nifi can be accessed on port 8080. The file https://github.com/romeokienzler/lfai_nifi/blob/master/AIF360.xml contains the template to create the flow. Now it is possible to copy the “fair” and “unfair” test data into the “in” folder and it will be consumed by the Nifi flow. This flow is illustrated in Figure 6.
After the flow has run, the bias metrics are attached as attributes to the flowfile as shown in Figure 7.
In the next steps we’ll add bias mitigation as well to this prototype. Then we’ll evaluate the other integration scenarios mentioned and identify the best way of integrating them to Acumos AI. Finally, we’ll integrate the remaining toolkits for adversarial robustness, explainability and accountability into Acumos AI.
We’ve shown that using a custom processor Trusted AI toolkits can be integrated into Apache Nifi and Acumos AI.