AIs limited to pure computation (Tool AIs) supporting humans, will be less intelligent, efficient, and economically valuable than more autonomous reinforcement-learning AIs (Agent AIs) who act on their own and meta-learn, because all problems are reinforcement-learning problems.
2016-09-07–2018-08-28 finished certainty: likely importance: 9
Autonomous AI systems (Agent AIs) trained using reinforcement learning can do harm when they take wrong actions, especially superintelligent Agent AIs. One solution would be to eliminate their agency by not giving AIs the ability to take actions, confining them to purely informational or inferential tasks such as classification or prediction (Tool AIs), and have all actions be approved & executed by humans, giving equivalently superintelligent results without the risk.
I argue that this is not an effective solution for two major reasons. First, because Agent AIs will by definition be better at actions than Tool AIs, giving an economic advantage. Secondly, because Agent AIs will be better at inference & learning than Tool AIs, and this is inherently due to their greater agency: the same algorithms which learn how to perform actions can be used to select important datapoints to learn inference over, how long to learn, how to more efficiently execute inference, how to design themselves, how to optimize hyperparameters, how to make use of external resources such as long-term memories or external software or large databases or the Internet, and how best to acquire new data. All of these actions will result in Agent AIs more intelligent than Tool AIs, in addition to their greater economic competitiveness. Thus, Tool AIs will be inferior to Agent AIs in both actions and intelligence, implying use of Tool AIs is a even more highly unstable equilibrium than previously argued, as users of Agent AIs will be able to outcompete them on two dimensions (and not just one).
One proposed solution to AI risk is to suggest that AIs could be limited purely to supervised/
Two variations on this limiting or boxing theme are
Oracle AI: Nick Bostrom, in Superintelligence (2014) (pg145–158) notes that while they can be easily ‘boxed’ and in some cases like P/
NP problems the answers can be cheaply checked or random subsets expensively verified, there are several issues with oracle AIs:
- the AI’s definition of ‘resources’ or ‘staying inside the box’ can change as it learns more about the world (ontological crises)
- responses might manipulate users into asking easy (and useless problems)
- making changes in the world can make it easier to answer questions about, by simplifying or controlling it (“All processes that are stable we shall predict. All processes that are unstable we shall control.”)
- even a successfully boxed and safe oracle or tool AI can be misused1
Tool AI (the term, as “tool mode” or “tool AGI”, was coined by Holden Karnofsky in a July 2011 discussion & elaborated on in a May 2013 essay, but the idea has probably been proposed before). To quote Karnofsky:
Google Maps—by which I mean the complete software package including the display of the map itself—does not have a “utility” that it seeks to maximize. (One could fit a utility function to its actions, as to any set of actions, but there is no single “parameter to be maximized” driving its operations.)
Google Maps (as I understand it) considers multiple possible routes, gives each a score based on factors such as distance and likely traffic, and then displays the best-scoring route in a way that makes it easily understood by the user. If I don’t like the route, for whatever reason, I can change some parameters and consider a different route. If I like the route, I can print it out or email it to a friend or send it to my phone’s navigation application. Google Maps has no single parameter it is trying to maximize; it has no reason to try to “trick” me in order to increase its utility. In short, Google Maps is not an agent, taking actions in order to maximize a utility parameter. It is a tool, generating information and then displaying it in a user-friendly manner for me to consider, use and export or discard as I wish.
Every software application I know of seems to work essentially the same way, including those that involve (specialized) artificial intelligence such as Google Search, Siri, Watson, Rybka, etc. Some can be put into an “agent mode” (as Watson was on Jeopardy) but all can easily be set up to be used as “tools” (for example, Watson can simply display its top candidate answers to a question, with the score for each, without speaking any of them.)…Tool-AGI is not “trapped” and it is not Unfriendly or Friendly; it has no motivations and no driving utility function of any kind, just like Google Maps. It scores different possibilities and displays its conclusions in a transparent and user-friendly manner, as its instructions say to do; it does not have an overarching “want,” and so, as with the specialized AIs described above, while it may sometimes “misinterpret” a question (thereby scoring options poorly and ranking the wrong one #1) there is no reason to expect intentional trickery or manipulation when it comes to displaying its results.
…Another way of putting this is that a “tool” has an underlying instruction set that conceptually looks like: “(1) Calculate which action A would maximize parameter P, based on existing data set D. (2) Summarize this calculation in a user-friendly manner, including what Action A is, what likely intermediate outcomes it would cause, what other actions would result in high values of P, etc.” An “agent,” by contrast, has an underlying instruction set that conceptually looks like: “(1) Calculate which action, A, would maximize parameter P, based on existing data set D. (2) Execute Action A.” In any AI where (1) is separable (by the programmers) as a distinct step, (2) can be set to the “tool” version rather than the “agent” version, and this separability is in fact present with most/
all modern software. Note that in the “tool” version, neither step (1) nor step (2) (nor the combination) constitutes an instruction to maximize a parameter—to describe a program of this kind as “wanting” something is a category error, and there is no reason to expect its step (2) to be deceptive…This is important because an AGI running in tool mode could be extraordinarily useful but far more safe than an AGI running in agent mode. In fact, if developing “Friendly AI” is what we seek, a tool-AGI could likely be helpful enough in thinking through this problem as to render any previous work on “Friendliness theory” moot.
…Is a tool-AGI possible? I believe that it is, and furthermore that it ought to be our default picture of how AGI will work
There are similar general issues with Tool AIs as with Oracle AIs:
- a human checking each result is no guarantee of safety; even Homer nods. A extremely dangerous or subtly dangerous answer might slip through; Stuart Armstrong notes that the summary may simply not mention the important (to humans) downside to a suggestion, or frame it in the most attractive light possible. The more a Tool AI is used, or trusted by users, the less checking will be done of its answers before the user mindlessly implements it.
- an intelligent, never mind superintelligent Tool AI, will have built-in search processes and planners which may be quite intelligent themselves, and in ‘planning how to plan’, discover dangerous instrumental drives and the sub-planning process execute them.2 (This struck me as mostly theoretical until I saw how well GPT-3 could roleplay & imitate agents purely by offline self-supervised prediction on large text databases—imitation learning is (batch) reinforcement learning too!)
- developing a Tool AI in the first place might require another AI, which itself is dangerous
Oracle AIs remain mostly hypothetical because it’s unclear how to write such utility functions. The second approach, Tool AI, is just an extrapolation of current systems but has two major problems aside from the already identified ones which cast doubt on Karnofsky’s claims that Tool AIs would be “extraordinarily useful” & that we should expect future AGIs to resemble Tool AIs rather than Agent AIs.
First and most commonly pointed out, agent AIs are more economically competitive as they can replace tool AIs (as in the case of YouTube upgrading from next-video prediction to REINFORCE3) or ‘humans in the loop’.4 In any sort of process, Amdahl’s law notes that as steps get optimized, the optimization does less and less as the output becomes dominated by the slowest step—if a step only takes 10% of the time or resources, then even infinite optimization of that step down to zero time/
At some point, there is not much point to keeping the human in the loop at all since they have little ability to check the AI choices and become ‘deskilled’ (think drivers following GPS directions), correcting less than they screw up and demonstrating that toolness is no guarantee of safety nor responsible use. (Hence the old joke: “the factory of the future will be run by a man and a dog; the dog will be there to keep the man away from the factory controls.”) For a successful autonomous program, just keeping up with growth alone makes it difficult to keep humans in the loop; the US drone warfare program has become such a central tool of US warfare that the US Air Force finds it extremely difficult to hire & retain enough human pilots overseeing its drones, and there are indications that operational pressures are slowly eroding the human control & turning them into rubberstamps, and for all its protestations that it would always keep a human in the decision-making loop, the Pentagon is, unsurprisingly, inevitably, sliding towards fully autonomous drone warfare as the next technological step to maintain military superiority over Russia & China. (See “Meet The New Mavericks: An Inside Look At America’s Drone Training Program”; “Future is assured for death-dealing, life-saving drones”; “Sam Altman’s Manifest Destiny”; “The Pentagon’s ‘Terminator Conundrum’: Robots That Could Kill on Their Own”; “Attack of the Killer Robots”)
Fundamentally, autonomous agent AIs are what we and the free market want; everything else is a surrogate or irrelevant loss function. We don’t want low log-loss error on ImageNet, we want to refind a particular personal photo; we don’t want excellent advice on which stock to buy for a few microseconds, we want a money pump spitting cash at us; we don’t want a drone to tell us where Osama bin Laden was an hour ago (but not now), we want to have killed him on sight; we don’t want good advice from Google Maps about what route to drive to our destination, we want to be at our destination without doing any driving etc. Idiosyncratic situations, legal regulation, fears of tail risks from very bad situations, worries about correlated or systematic failures (like hacking a drone fleet), and so on may slow or stop the adoption of Agent AIs—but the pressure will always be there.
So for this reason alone, we expect to see Agent AIs to systematically be preferred over Tool AIs unless they’re considerably worse.
Agent AIs will be chosen over Tool AIs—for reasons aside from not being what anyone wants and something that will be severely penalized by free markets or simply there being multiple agents choosing whether to use a Tool AI or an Agent AI in any kind of competitive scenario—also suffer from the problem that the best Tool AI’s performance/
An Agent AI clearly benefits from being a better Tool AI, so it can better understand its environment & inputs; but less intuitively, any Tool AI benefits from agentiness. An Agent AI has the potential, often realized in practice, to outperform any Tool AI: it can get better results with less computation, less data, less manual design, less post-processing of its outputs, on harder domains.
(Trivial proof: Agent AIs are supersets of Tool AIs—an Agent AI, by not taking any actions besides communication or random choice, can reduce itself to a Tool AI; so in cases where actions are unhelpful, it performs the same as the Tool AI, and when actions can help, it can perform better; hence, an Agent AI can always match or exceed a Tool AI. At least, assuming sufficient data that in the environments where actions are not helpful, it can learn to stop acting, and in the ones where they are, it has a distant enough horizon to pay for the exploration. Of course, you might agree with this but simply believe that intelligence-wise, Agent AIs == Tool AIs.)
Every sufficiently hard problem is a reinforcement learning problem.
More seriously, not all data is created equal. Not all data points are equally valuable to learn from, require equal amounts of computation, should be treated identically, should inspire identical followup data sampling, or actions. Inference and learning can be much more efficient if the algorithm can choose how to compute on what data with which actions.
There is no hard Cartesian boundary between an algorithm & its environment such that control of the environment is irrelevant to the algorithm and vice-versa and its computation can be carried out without regard to the environment—there are simply many layers between the core of the algorithm and the furthest part of the environment, and the more layers that the algorithm can model & control, the more it can do. Consider Google Maps/
This is a highly general point which can be applied on many levels. This point often arises in classical statistics/
The wide variety of uses of action is a major theme in recent work in AI (specifically, deep learning/
Roughly, we can try to categorize the different kinds of agentiness by the ‘level’ of the NN they work on. There are:
actions internal to a computation:
- intermediate states
- accessing the external ‘environment’
- amount of computation
- enforcing constraints/
finetuning quality of output
- changing the loss function applied to output
actions internal to training the NN:
- the gradient itself
- size & direction of gradient descent steps on each parameter
- overall gradient descent learning rate and learning rate schedule
- choice of data samples to train on
internal to the dataset
- active learning
- optimal experiment design
internal to the NN design step
- hyperparameter optimization
- NN architecture
internal to interaction with environment
- adaptive experiment /
multi-armed bandit / exploration for reinforcement learning
- adaptive experiment /
Inside a specific NN, while computing the output for an input question, a NN can make choices about how to handle it.
It can choose what parts of the input to run most of its computations on, while throwing away or computing less on other parts of the input, which are less relevant to the output, using “attention mechanisms” (eg Olah & Carter 2016, Hahn & Keller 2016, Bellver et al 2016, Mansimov et al 2015, Gregor et al 2015, Xu 2015, Larochelle & Hinton 2010, Bahdanau et al 2015, Ranzato 2014, Mnih et al 2014, Sordoni et al 2016, Kaiser & Bengio 2016). Attention mechanisms are responsible for many increases in performance, but especially improvements in RNNs’ ability to do sequence-to-sequence translation by revisiting important parts of the sequence (Vaswani et al 2017), image generation and captioning, and in CNNs’ ability to recognize images by focusing on ambiguous or small parts of the image, even for adversarial examples (Luo et al 2016). They are a major trend in deep learning, as it is often the case that some parts of the input are more important than others and enable both global & local operations to be learned, with increasingly too many examples of attention to list (with a trend as of 2018 towards using attention as the major or only construct).
Many designs can be interpreted as using attention. The bidirectional RNN also often used in natural language translation doesn’t explicitly use attention mechanisms but is believed to help by giving the RNN a second look at the sequence. Indeed, so universal that it often goes without mention is that the LSTM/GRU mechanism which improves almost all RNNs is itself a kind of attention mechanism: the LSTM cells learn which parts of the hidden state/
Extending attention, a NN can choose not just which parts of an input to look at multiple times, but also how long to keep computing on it, “adaptive computation” (Graves 2016a, Figurnov et al 2016, Silver et al 2016b, Zamir et al 2016, Huang et al 2017, Li et al 2017, Wang et al 2017, Teerapittayanon et al 2017, Huang et al 2017, Li et al 2017b, Campos et al 2017, McGill & Perona 2017, Bolukbasi et al 2017, Wu et al 2017, Seo et al 2017, Lieder et al 2017, Dehghani et al 2018, Buesing et al 2019): so it iteratively spends more computation on hard parts of problem within a given computational budget6. Neural ODEs are an interesting example of a model which are sort of like adaptive RNNs in that they can be run repeatedly by the ODE solver, adaptively, to refine their output to a target accuracy, and the ODE solver can be considered a kind of agent as well.
Attention generally doesn’t change the nature of the computation aside from the necessity of actions over the input, but actions can be used to bring in different computing paradigms. For example, the entire field of “differentiable neural computer”/
Anywhere We’re Using Heuristics To Make a Decision!
- Compilers: instruction scheduling, register allocation, loop nest parallelization strategies, …
- Networking: TCP window size decisions, backoff for retransmits, data compression, …
- Operating systems: process scheduling, buffer cache insertion/
replacement [eg Lagar-Cavilla et al 2019 for compressed RAM], file system prefetching [eg Hashemi et al 2018, memory allocation (Maas et al 2020)], …
- Job scheduling systems: which tasks/
VMs to co-locate on same machine, which tasks to pre-empt, … [eg Chen & Tian 2018]
- ASIC design: physical circuit placement, test case selection, …
Anywhere We’ve Punted to a User-Tunable Performance Option! Many programs have huge numbers of tunable command-line flags, usually not changed from their defaults (
--eventmanager_threads=16 --bigtable_scheduler_batch_size=8 --mapreduce_merge_memory=134217728
Meta-learn everything. ML:
- learning placement decisions
- learning fast kernel implementations
- learning optimization update rules
- learning input preprocessing pipeline steps
- learning activation functions
- learning model architectures for specific device types, or that are fast for inference on mobile device X, learning which pre-trained components to reuse, …
datacenter networking design:
- learning best design properties by exploring design space automatically (via simulator) [see Dean 2019]
Finally, one interesting variant on this theme is treating an inferential or generative problem as a reinforcement learning problem in a sort of environment with global rewards. Many times the standard loss function is inapplicable, or the important things are global, or the task is not really well-defined enough (in a “I know it when I see it” sense for the human) to nail down as a simple differentiable loss with predefined labels such as in an image classification problem; in these cases, one cannot do standard supervised training to minimize the loss but must start using reinforcement learning to directly optimize a reward—treating outputs such as classification labels as ‘actions’ which may eventually result in a reward. For example, in a char-RNN generative text model trained by predicting a character conditional on the previous, one can generative reasonable text samples by greedily picking the most likely next character and occasionally a less likely character for diversity, but one can generate higher quality samples by exploring longer sequences with beam search or nucleus sampling, and one can improve generation further by adding utility functions for global properties & applying RL algorithms such as Monte Carlo tree search (MCTS) for training or runtime maximization of an overall trait like translation/
The training of a NN by stochastic gradient descent might seem to be independent of any considerations of ‘actions’, but it turns to be another domain where you can go “what if we treated this as a MDP?” and it’s actually useful. Specifically, gradient descent requires selection of which data to put into a minibatch, how large a change to make to parameters in general based on the error in the current minibatch (the learning rate hyperparameter), or how much to update each individual parameter each minibatch (perhaps having some neurons which get tweaked much less than others). Actions are things like selecting 1 out of n possible minibatches to do gradient descent on, or selecting 1 out of n possible learning rates with the learning rate increasing/
We have previously looked at sampling from existing datasets: training on hard samples, and so on. One problem with existing datasets is that they can be inefficient—perhaps they have class imbalance problems where some kinds of data are overrepresented and what is really needed for improved performance is more of the other kinds of data. An image classification CNN doesn’t need 99 dog photos & 1 cat photos, it wants 50 dog photos & 50 cat photos. (Quite aside from the fact that there’s not enough information to classify other cat photos based on just 1 exemplar, the CNN will simply learn to always classify photos as ‘dog’.) One can try to fix this by choosing predominately from the minority classes, or by changing the loss function to make classifying the minority class correctly much more valuable than classifying the majority class.
Even better is if the NN can somehow ask for new data, be given additional/
“I suspect that less than 10 years from now, all of the DL training/
architecture tricks that came from the arXiv firehose over 2015–2019 will have been entirely superseded by automated search techniques. The future: no alchemy, just clean APIs, and quite a bit of compute.”
François Chollet, 2019-01-7
Moving on to more familiar territory, we have hyperparameter optimization using random search or grid search or Bayesian Gaussian processes to try training a possible NN, observe interim (Swersky et al 2014) and final performance, and look for better hyperparameters. But if “hyperparameters are parameters we don’t know how to learn yet”, then we can see the rest of neural network architecture design as being hyperparameters too: what is the principled difference between setting a dropout rate and setting the number of NN layers? Or between setting a learning rate schedule and the width of NN layers or the number of convolutions or what kind of pooling operators are used? There is none; they are all hyperparameters, just that usually we feel it is too difficult for hyperparameter optimization algorithms to handle many options and we limit them to a small set of key hyperparameters and use “grad student descent” to handle the rest of the design. So… what if we used powerful algorithms (viz. neural networks) to design compiled code, neural activations, units like LSTMs, or entire architectures (Zoph & Le 2016, Baker et al 2016, Chen et al 2016, Duan et al 2016, Wang et al 2016, Castronovo 2016, Ha et al 2016, Fernando et al 2017, Ravi & Larochelle 2017, Yoo et al 2017, Negrinho & Gordon 2017, Miikkulainen et al 2017, Real et al 2017, Hu et al 2017, Johnson et al 2017, Veniat & Denoyer 2017, Munkhdalai & Yu 2017, Cai et al 2017, Zoph et al 2017, Brock et al 2017, Zhong et al 2017, Ashok et al 2017, Ebrahimi et al 2017, Ramachandran et al 2017, Anonymous 2017, Wistuba 2017, Schrimpf et al 2017, Huang et al 2018, Real et al 2018, Vasilache et al 2018, Elsken et al 2018, Chen et al 2018, Zhou et al 2018, Zela et al 2018, Tan et al 2018, Chen et al 2018a, Cheng et al 2018b, Anonymous 2018, Cheng et al 2018c, Guo et al 2018, Cai et al 2018, So et al 2019, Ghiasi et al 2019, Tan & Le 2019, An et al 2019, Gupta & Tan 2019, Piergiovanni et al 2018)?
The logical extension of these “neural networks all the way down” papers is that an actor like Google/
Finally, we come to actions in environments which aren’t purely virtual. Adaptive experiments, multi-armed bandits, reinforcement learning etc will outperform any purely supervised learning. For example, AlphaGo trained as a pure supervised-learning Tool AI, predicting next moves of human Go games in a KGS dataset, but that was only a prelude to the self-play, which boosted it from professional player to superhuman level; aside from replacing loss functions (a classification loss like log loss vs victory), the AlphaGo NNs were able to explore tactics and positions that never appeared in the original human dataset. The rewards can also help turn an unsupervised problem (what is the structure or label of each frame of a video game?) into more of a semi-supervised problem by providing some sort of meaningful summary: the reward. A DQN Atari Learning Environment (ALE) agent will, without any explicit image classification, learn to recognize & predict objects in a game which are relevant to achieving a high score.
So to put it concretely: CNNs with adaptive computations will be computationally faster for a given accuracy rate than fixed-iteration CNNs, CNNs with attention classify better than CNNs without attention, CNNs with focus over their entire dataset will learn better than CNNs which only get fed random images, CNNs which can ask for specific kinds of images do better than those querying their dataset, CNNs which can trawl through Google Images and locate the most informative one will do better still, CNNs which access rewards from their user about whether the result was useful will deliver more relevant results, CNNs whose hyperparameters are automatically optimized by an RL algorithm (and possibly trained directly by a NN) will perform better than CNNs with handwritten hyperparameters, CNNs whose architecture as well as standard hyperparameters are designed by RL agents will perform better than handwritten CNNs… and so on. (It’s actions all the way down.)
The drawback to all this is the implementation difficulty is higher, the sample efficiency can be better or worse (individual parts will have greater sample-efficiency but data will be used up training the additional flexibility of other parts), and the computation requirements for training can be much higher; but the asymptotic performance is better, and the gap probably grows as GPUs & datasets get bigger and tasks get more difficult & valuable in the real world.
Why does treating all these levels as decision or reinforcement learning problems help so much?
One answer is that most points are not near any decision boundary, or are highly predictable and contribute little information. Optimizing explorations can often lead to prediction/
Another answer is the “curse of dimensionality”: in many environments, the tree of possible actions and subsequent rewards grows exponentially, so any sequence of actions over more than a few timesteps is increasingly unlikely to ever be sampled, and sparse rewards will be increasingly likely to be observed. Even if an important trajectory is executed at random and a reward obtained, it will be equally unlikely to ever be executed again—whereas some sort of RL agent, whose beliefs affect its choice of actions, can sample the important trajectory repeatedly, and rapidly converge on an estimate of its high value and continue exploring more deeply.
A dataset of randomly generated sequences of robot arm movements intended to grip an object would likely include no rewards (successful grips) at all, because it requires a long sequence of finely calibrated arm movements; with no successes, how could the tool AI learn to manipulate an arm? It must be able to make progress by testing its best arm movement sequence candidate, then learn from that and test the better arm movement, and so on, until it succeeds. Without any rewards or ability to hone in good actions, only the initial states will be observed and progress will be extremely slow compared to an agent who can take actions and explore novel parts of the environment (eg the problem of Montezuma’s Revenge in the Atari Learning Environment: because of reward sparsity, an epsilon-greedy might as well not be an agent compared to some better method of exploring like density-estimation in Bellemare et al 2016.)
Or imagine training a Go program by creating a large dataset of randomly generated Go boards, then evaluating each possible move’s value by playing out a game between random agents from it; this would not work nearly as well as training on actual human-generated board positions which target the vanishingly small set of high-quality games & moves. The exploration homes in on the exponentially shrinking optimal area of the movement tree based on its current knowledge, discarding the enormous space of bad possible moves. In contrast, a tool AI cannot lift itself up by its bootstraps. It merely gives its best guess on the static current dataset, and that’s that. If you don’t like the results, you can gather more data, but it probably won’t help that much because you’ll give it more of what it already has.
Hence, being a secret agent is much better than being a tool.
Even if the oracle itself works exactly as intended, there is a risk that it would be misused. One obvious dimension of this problem is that an oracle AI would be a source of immense power which could give a decisive strategic advantage to its operator. This power might be illegitimate and it might not be used for the common good. Another more subtle but no less important dimension is that the use of an oracle could be extremely dangerous for the operator herself. Similar worries (which involve philosophical as well as technical issues) arise also for other hypothetical castes of superintelligence. We will explore them more thoroughly in Chapter 13. Suffice it here to note that the protocol determining which questions are asked, in which sequence, and how the answers are reported and disseminated could be of great significance. One might also consider whether to try to build the oracle in such a way that it would refuse to answer any question in cases where it predicts that its answering would have consequences classified as catastrophic according to some rough-and-ready criteria.
Superintelligence, pg152–153, pg158:
With advances in artificial intelligence, it would become possible for the programmer to offload more of the cognitive labor required to figure out how to accomplish a given task. In an extreme case, the programmer would simply specify a formal criterion of what counts as success and leave it to the AI to find a solution. To guide its search, the AI would use a set of powerful heuristics and other methods to discover structure in the space of possible solutions. It would keep searching until it found a solution that satisfied the success criterion…Rudimentary forms of this approach are quite widely deployed today…A second place where trouble could arise is in the course of the software’s operation. If the methods that the software uses to search for a solution are sufficiently sophisticated, they may include provisions for managing the search process itself in an intelligent manner. In this case, the machine running the software may begin to seem less like a mere tool and more like an agent. Thus, the software may start by developing a plan for how to go about its search for a solution. The plan may specify which areas to explore first and with what methods, what data to gather, and how to make best use of available computational resources. In searching for a plan that satisfies the software’s internal criterion (such as yielding a sufficiently high probability of finding a solution satisfying the user-specified criterion within the allotted time), the software may stumble on an unorthodox idea. For instance, it might generate a plan that begins with the acquisition of additional computational resources and the elimination of potential interrupters (such as human beings). Such “creative” plans come into view when the software’s cognitive abilities reach a sufficiently high level. When the software puts such a plan into action, an existential catastrophe may ensue….The apparent safety of a tool-AI, meanwhile, may be illusory. In order for tools to be versatile enough to substitute for superintelligent agents, they may need to deploy extremely powerful internal search and planning processes. Agent-like behaviors may arise from such processes as an unplanned consequence. In that case, it would be better to design the system to be an agent in the first place, so that the programmers can more easily see what criteria will end up determining the system’s output.
As the lead author put it in a May 2019 talk about REINFORCE on YouTube, the benefit is not simply better prediction but in superior consideration of downstream effects of all recommendations, which are ignored by predictive models: this produced “The largest single launch improvement in YouTube for two years” because “We can really lead the users toward a different state, versus recommending content that is familiar”.↩︎
It might be thought that by expanding the range of tasks done by ordinary software, one could eliminate the need for artificial general intelligence. But the range and diversity of tasks that a general intelligence could profitably perform in a modern economy is enormous. It would be infeasible to create special-purpose software to handle all of those tasks. Even if it could be done, such a project would take a long time to carry out. Before it could be completed, the nature of some of the tasks would have changed, and new tasks would have become relevant. There would be great advantage to having software that can learn on its own to do new tasks, and indeed to discover new tasks in need of doing. But this would require that the software be able to learn, reason, and plan, and to do so in a powerful and robustly cross-domain manner. In other words, it would need general intelligence. Especially relevant for our purposes is the task of software development itself. There would be enormous practical advantages to being able to automate this. Yet the capacity for rapid self-improvement is just the critical property that enables a seed AI to set off an intelligence explosion.
While Google Maps was used as a paradigmatic example of a Tool AI, it’s not clear how hard this can be pushed, even if we exclude the road system itself: Google Maps/
Waze is, of course, trying to maximize something—traffic & ad revenue. Google Maps, like any Google property, is doubtless constantly running A/ B testson its users to optimize for maximum usage, its users are constantly feeding in data about routes & traffic conditions to Google Maps/ Waze through the website interface & smartphone GPS/WiFi geographic logs, and to the extent that users make any use of the information & increase/ decrease their use of Google Maps which many do so blindly, Google Maps will get feedback after changing the real world (sometimes to the intense frustration of those affected, who try to manipulate it back)… Is Google Maps/ Waze a Tool AI or a large-scale Agent AI?
It is in a POMDP environment, it has a clear reward function in terms of website traffic, and it has a wide set of actions it continuously explores with randomization from various sources; even though it was designed to be a Tool AI, from an abstract perspective, one would have to consider it to have evolved into an Agent AI due to its commercial context and use in real-world actions, whether Google likes it or not. We might consider Google Maps to be a “secret agent”: it is not a Tool AI but an Agent AI with a hidden & highly opaque reward function. This is probably not an ideal situation.↩︎
If the NN is trained to minimize error alone, it’ll simply spend as much time as possible on every problem; so a cost is imposed on each iteration to encourage it to finish as soon as it has a good answer, and learn to finish sooner. And how do we decide what costs to impose on the NN for deciding whether to loop another time or emit its current best guess as good enough? Well, that’ll depend on the cost of GPUs and the economic activity and the utility of results for the humans…↩︎
One question I remember came from Tieleman. He asked the panelists about their opinions on active learning/
exploration as an option for efficient unsupervised learning. Schmidhuber and Murphy responded, and before I reveal their response, I really liked it. In short (or as much as I’m certain about my memory), active exploration will happen naturally as the consequence of rewarding better explanation of the world. Knowledge of the surrounding world and its accumulation should be rewarded, and to maximize this reward, an agent or an algorithm will active explore the surrounding area (even without supervision.) According to Murphy, this may reflect how babies learn so quickly without much supervising signal or even without much unsupervised signal (their way of active exploration compensates the lack of unsupervised examples by allowing a baby to collect high quality unsupervised examples.)
An example here might be the use of ‘ladders’ or ‘mirroring’ in Go—models trained in a purely supervised fashion on a dataset of Go games can have serious difficulty responding to a ladder or mirror because those strategies are so bad that no human would play them in the dataset. Once the Tool AI has been forced ‘off-policy’, its predictions & inferences may become garbage because it’s never seen anything like those states before; an agent will be better off because it’ll have been forced into them by exploration or adversarial training and have learned the proper responses. This sort of bad behavior leads to quadratically increasing regret with passing time: Ross & Bagnall 2010.↩︎