-
Notifications
You must be signed in to change notification settings - Fork 1
/
Copy pathOLD aises_3_2
418 lines (417 loc) · 25.8 KB
/
OLD aises_3_2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
<h1 id="sec:bias">3.2 Bias</h1>
<h3 id="introduction">3.2.1 Introduction</h3>
<p><strong>AI systems can amplify undesirable biases.</strong> AI
systems are being increasingly deployed throughout society. If these
influential systems have biases, they can reinforce disparities and
produce widespread, long-term harms. In AI, <em>bias</em> refers to a
consistent, systematic, or undesirable distortion in the outcomes
produced by an AI system. These outcomes can be predictions,
classifications, or decisions. Bias can be influenced by many factors,
including erroneous assumptions, training data, or human biases. Biases
in modern deep learning systems can be especially consequential. While
not all forms of bias are harmful, we focus on biases that are socially
relevant because of their harms. We must proactively prevent bias to
avoid its harms. This section overviews bias in AI and outlines some
mitigation strategies.</p>
<p><strong>Aspects of bias in AI.</strong> A bias is <em>systematic</em>
when it includes a pattern of repeated deviation from the true values in
one direction. Unlike random unstructured errors, or “noise,” these
biases are not reliably fixed by just adding more data. Resolving
ingrained biases often requires changing algorithms, data collection
practices, or how the AI system is applied. <em>Algorithmic bias</em>
occurs when any computer system consistently produces results that
disadvantage certain groups over others. Some biases are relatively
harmless, like a speech recognition system that is better at
interpreting human language than whale noises. However, other forms of
bias can result in serious social harms, such as partiality to certain
groups, inequity, or unfair treatment.</p>
<p><strong>Bias can manifest at every stage of the AI
lifecycle.</strong> From data collection to real-world deployment, bias
can be introduced through multiple mechanisms at any step in the
process. Historical and social prejudices produce skewed training data,
propagating flawed assumptions into models. Flawed models can cement
biases into the AI systems that help make important societal decisions.
In addition, humans misinterpreting results can further compound bias.
After deployment, biased AI systems can perpetuate discriminatory
patterns through harmful feedback loops that exacerbate bias. Developing
unbiased AI systems requires proactively identifying and mitigating
biases across the entire lifecycle.</p>
<figure id="fig:enter-label">
<embed src="https://raw.githubusercontent.com/WilliamHodgkins/AISES/main/images/bias_diagram.png" class="tb-img-full" style="width: 90%"/>
<p class="tb-caption">Figure 3.1: Systematic psychological, historical, and social biases can lead to algorithmic biases
within AI systems. </p>
<!--<figcaption>Systematic psychological, historical, and social biases can-->
<!--lead to algorithmic biases within AI systems.</figcaption>-->
</figure>
<p><strong>Biases in AI often reflect systemic biases.</strong>
Systematic biases can occur even against developers’ intentions. For
instance, Amazon developed an ML-based resume-screening algorithm
trained on historical hiring decisions. However, as the tech industry is
predominantly male, this data reflected skewed gender proportions in the
data (about 60% male and 40% female) <span class="citation"
data-cites="amazon_bias">[1]</span>. Consequently, the algorithm scored
male applicants higher than equally qualified women, penalizing resumes
with implicit signals like all-female colleges. The algorithm
essentially reproduced real-world social biases in hiring and
employment. This illustrates how biased data, when fed into AI systems,
can inadvertently perpetuate discrimination. Organizations must be
vigilant about biases entering any stage of the machine learning
pipeline.</p>
<p><strong>In many countries, some social categories are legally
protected from discrimination.</strong> Groups called <em>protected
classes</em> are legally protected from harmful forms of bias. These
often include race, religion, sex/gender, sexual orientation, ancestry,
disability, age, and others. Laws in many countries prohibit denying
opportunities or resources to people solely based on these protected
attributes. Thus, AI systems exhibiting discriminatory biases against
protected classes can produce unlawful outcomes. Mitigating algorithmic
bias is crucial for ensuring that AI complies with equal opportunity
laws by avoiding discrimination.</p>
<p><strong>Conclusion.</strong> Identifying and mitigating biases is
crucial to build social trust in AI. This section discusses the main
sources of bias as well as strategies researchers are exploring to
mitigate bias. However, this overview aims to be brief, so it is not
exhaustive.<p>
</p>
<h2 id="sources-of-bias">3.2.1 Sources of Bias</h2>
<p>Biases can arise from multiple sources, both from properties of the
AI system itself and human interaction with the system. This section
discusses common sources of harmful biases in AI systems, although there
are many more. First, we will discuss technical sources of bias,
primarily from flawed data or objectives. Then, we will review some
biases that arise from interactions between humans and AI systems.</p>
<h3 id="technical-sources-of-bias-in-ai-systems">Technical Sources of
Bias in AI Systems</h3>
<p><strong>An overview of technical sources of bias.</strong> In this
section, we will review some sources of bias in technical aspects of AI
systems. First, we will investigate some <em>data-driven</em> sources of
biases, including flawed training data, subtle patterns that can be used
to discriminate, biases in how the data is generated or reported, and
underlying societal biases. Flawed or skewed training data can propagate
biases into the model’s weights and predictions. Then, we show how RL
training environments and objectives can also reinforce bias.</p>
<p><strong>ML models trained on biased datasets can learn and reinforce
harmful societal biases.</strong> AI systems learn from human-generated
data, absorbing both valuable knowledge and harmful biases. Even when
unintentional, this data frequently mirrors ingrained societal
prejudices. As a result, AI models can propagate real-world
discrimination by learning biases from their input data. For instance, a
lawsuit found that Facebook’s ad targeting algorithm violated the Fair
Housing Act because it learned to exclude users from seeing housing ads
based on race, gender, or other protected traits. Similarly, ML models
can reflect political biases, deprioritizing users from specific
political affiliations by showing their content to smaller audiences. As
another example, an NLP model trained on a large corpus of internet text
learned to reinforce gender stereotypes, completing sentence structures
of the format “man is to X as woman is to Y” with content such as “man
is to computer programmer as woman is to homemaker” <span
class="citation" data-cites="bolukbasi2016man">[2]</span>. These
examples show how ML models can amplify existing social biases.</p>
<p><strong>Models can learn to discriminate based on subtle
correlations.</strong> One intuitive way to fix bias is to remove
protected attributes like gender and achieve “fairness through
unawareness.” But this is not enough to remove bias. ML models can learn
subtle correlations that serve as proxies for these attributes. For
example, even in datasets with gender information removed,
resume-screening models learned to associate women with certain colleges
and assigned them lower scores <span class="citation"
data-cites="amazon_bias">[1]</span>. In another study, ML models
erroneously labeled images of people cooking as women, due to learned
gender biases <span class="citation"
data-cites="zhao2017men">[3]</span>. Thus, models can discriminate even
when the data does not contain direct data about protected classes. This
hidden discrimination can harm protected groups despite efforts to
prevent bias.</p>
<p><strong>Biased or unrepresentative data collection can lead to biased
decisions.</strong> Training data reflects biases in how the data was
collected. If the training data is more representative of some groups
than others, the predictions from the model may also be systematically
worse for the underrepresented groups. Thus, the model will make worse
or biased decisions for the group that is represented less in the
dataset. Imbalances in training data occur when the data is skewed with
respect to output labels, input features, and data structure. For
instance, a disease prediction dataset with 100,000 healthy patients but
only 10 sick patients exhibits a large class imbalance. The minority
class with fewer examples is underrepresented.</p>
<p><strong>Several other problems can introduce bias in AI training
data.</strong> Systematic problems in the data can add bias. For
instance, <em>reporting bias</em> occurs when the relative frequency of
examples in the training data misrepresents real-world frequencies.
Often, the frequency of outcomes in legible data does not reflect their
actual occurrence. For instance, the news amplifies shocking events and
under-reports normal occurrences or systematic, ongoing
problems—reporting shark attacks rather than cancer deaths. <em>Sampling
bias</em> occurs when the data collection systematically over-samples
some groups and undersamples others. For instance, facial recognition
datasets in Western countries often include many more lighter-skinned
individuals. <em>Labeling bias</em> is introduced later in the training
process, when systematic errors in the data labeling process distort the
training signal for the model. Humans may introduce their own subjective
biases when labeling data.<p>
Beyond problems with the training data, the training environments and
objectives of RL models can also exhibit problems that promote bias.
Now, we will review some of these sources of bias.</p>
<p><strong>Training environments can also amplify bias.</strong>
<em>Reward bias</em> occurs when the environments used to train RL
models introduce biases through improper rewards. RL models learn based
on the rewards received during training. If these rewards fail to
penalize unethical or dangerous behavior, RL agents can learn to pursue
immoral outcomes. For example, models trained in video games may learn
to accomplish goals by harming innocents if these actions are not
sufficiently penalized in training. Some training environments may fail
to encourage good behaviors enough, while others can even incentivize
bad behavior by rewarding RL agents for taking harmful actions. Humans
must carefully design training environments and incentives that
encourage ethical learning and behavior <span class="citation"
data-cites="gilbert2022choices">[4]</span>.</p>
<p><strong>RL models can optimize for training objectives that amplify
bias or harm.</strong> Reinforcement learning agents will try to
optimize the goals they are given in training, even if these objectives
are harmful or biased, or reflect problematic assumptions about value.
For example, a social media news feed algorithm trained to maximize user
engagement may prioritize sensational, controversial, or inflammatory
content to increase ad clicks or watch time. Technical RL objectives
often make implicit value assumptions that cause harm, especially when
heavily optimized by a powerful AI system <span class="citation"
data-cites="stray2021optimizing kross2013facebook">[5], [6]</span>. News
feed algorithms implicitly assume that how much a user engages with some
content is a high-quality indicator of the <em>value</em> of that
content, therefore showing it to even more users. After all, social
media companies train ML models to maximize ad revenue by increasing
product usage, rather than fulfilling goals that are harder to monetize
or quantify, such as improving user experience or promoting accurate and
helpful information. Especially when taken to their extreme and applied
at a large scale, RL models with flawed training objectives can
exacerbate polarization, echo chambers, and other harmful outcomes.
Problems with the use of flawed training objectives are further
discussed in the Proxy Gaming section.<p>
In summary, biased training data, flawed objectives, and other technical
aspects of ML models can introduce bias, illustrating how ML bias can
perpetuate existing disparities. Carefully scrutinizing the technical
details of models is crucial for mitigating these biases.</p>
<h3 id="biases-from-human-ai-interactions">Biases from human-AI
interactions</h3>
<p><strong>Interactions between humans and AI systems can produce many
kinds of bias.</strong> It is not enough to just ensure that AI systems
have unbiased training data: humans interacting with AI systems can also
introduce biases during development, usage, and monitoring. Flawed
evaluations allow biases to go unnoticed before models are deployed.
<em>Confirmation bias</em> in the context of AI is when people focus on
algorithm outputs that reinforce their pre-existing views, dismissing
opposing evidence. Humans may emphasize certain model results over
others, skewing the outputs even if the underlying AI system is
reliable. This distorts our interpretation of model decisions.
<em>Overgeneralization</em> occurs when humans draw broad conclusions
about entire groups based on limited algorithmic outputs that reflect
only a subset. Irrationality and human cognitive bias play a substantial
role in biasing AI systems.</p>
<p><strong>Human-AI system biases can be reinforced by feedback
loops.</strong> <em>Feedback loops</em> in human-AI systems often arise
when the output of an AI system is used as input in future AI models. An
AI system trained on biased data could make biased decisions that are
fed into future models, reinforcing bias in a self-perpetuating cycle.
We speak more about these feedback loops in the Complex Systems chapter.
<em>Self-fulfilling prophecies</em> can occur when an algorithmic
decision influences actual outcomes, as the model reinforces its own
biases and influences future input data <span class="citation"
data-cites="krueger2020hidden">[7]</span>. In this way, models can
amplify real-world biases, making them even more real. For example, a
biased loan-approval algorithm could deny loans to lower-income groups,
reinforcing real-world income disparities that are then reflected in the
training data for future models. This process can make bias more severe
over time.</p>
<p><strong>Automation and measurability induce bias.</strong> Bias can
be amplified by <em>automation bias</em>, where humans favor algorithmic
decisions over human decisions, even if the algorithm is wrong or
biased. This blind trust can cause harm when the model is flawed.
Similarly, a <em>bias toward the measurable</em> can promote a general
preference for easily quantifiable attributes. Human-AI systems may
overlook important qualitative aspects and less tangible factors.</p>
<p><strong>Despite their problems, AI systems can be less biased than
humans.</strong> Although there are legitimate concerns, AI systems used
for hiring and other sensitive tasks may sometimes lead to <em>less</em>
biased decisions when compared with human decision-makers. Humans often
harbor strong biases that skew their judgment in these decisions. With
careful oversight and governance, AI holds promise to reduce certain
biases relative to human motivations.<p>
In summary, human biases and blind spots during development, usage, and
governance of AI systems contribute to biased outputs from AI systems. A
holistic approach for critically examining human-AI interaction is
required to address this.</p>
<h2 id="strategies-for-bias-mitigation">3.2.2 Strategies for Bias
Mitigation</h2>
<p><strong>Multiple complementary approaches can help address bias in AI
systems.</strong> Even with the best intent, biases in AI can be
difficult to anticipate. Mitigating the complicated problem of bias
calls for combining engineering, social, legal, and governance
strategies. For instance, one promising technical approach involves
training an adversarial network to predict a protected variable from an
ML model’s outputs <span class="citation"
data-cites="zhang2018mitigating">[8]</span>. By penalizing the model
when the adversary succeeds at predicting a variable like race or
political affiliation from the model’s outputs, the model is forced to
avoid discrimination and make predictions that do not unfairly depend on
sensitive attributes. When applied well, this can minimize biases.
However, even the best technical approaches have limitations, and a
holistic solution will integrate many approaches.</p>
<p><strong>Engineering strategies for reducing bias must be paired with
non-technical strategies.</strong> Ultimately, technical debiasing alone
is insufficient. Social processes are crucial as humans adapt to AI. We
speak about this at length in the Systemic Factors section, but here we will only
mention a few ideas. For instance, <em>early bias detection</em>
involves creating checks to identify risks of bias before the AI system
is deployed or even trained, so that models that have discriminatory
outputs can be rejected before they cause harm. Similarly, <em>gradual
deployment</em> safely transitions AI systems into use while monitoring
them for bias so that harms can be identified early and reversed.
<em>Regulatory changes</em> can require effective mitigation strategies
by law, mandating transparency and risk mitigation in safety-critical AI
systems, as we discuss in the Governance chapter.</p>
<p><strong>Participatory design can mitigate bias in AI
development.</strong> An important non-technical strategy for bias
reduction is stakeholder engagement, or deeply engaging impacted groups
in the design of the AI system to identify potential biases proactively.
Diverse teams and users can also help engineering teams incorporate
diverse perspectives into the R&D process of AI models to anticipate
potential biases proactively. One approach to proactively addressing
bias is <em>participatory design</em>, which aims to include those
affected by a developing technology as partners in the design process to
ensure that the final product meets diverse human interests. For
example, before implementing an AI notetaking assistant for doctors,
participatory design can require hospitals to improve the system based
on feedback from all stakeholders during iterative design sessions with
nurses, doctors, and patients. Rather than just evaluating ML models on
test sets, developers should consult with the affected groups during the
design process. Adding oversight mechanisms for rejecting models with
discriminatory outputs can also enable catching biases before AI models
affect real decisions.</p>
<p><strong>Independent audits are important for identifying biases in AI
systems before deployment.</strong> Auditors can systematically evaluate
datasets, models, and outputs to uncover discrimination and hold the
developers of AI systems accountable. There are several signs of bias to
look for when auditing datasets. For example, auditors can flag missing
data for certain subgroups, which indicates underrepresentation.
<em>Data skew</em>, where certain groups are misrepresented compared to
their real-world prevalence, is another sign of bias. Patterns and
correlations with protected classes could indicate illegal biases.
Auditors can also check for disparities in the model outputs. By
auditing throughout the process, developers can catch biases early,
improving data and models <em>before</em> their biases propagate. Rather
than waiting until after the system has harmful impacts, meticulous
audits should be integrated as part of the engineering and design
process for AI systems <span class="citation"
data-cites="raji2020closing">[9]</span>. Audits are especially effective
when conducted independently by organizations without a stake in the AI
system’s development, allowing for impartial and rigorous auditing
throughout the process.</p>
<p><strong>Effective model evaluation is a crucial way to reduce
bias.</strong> An important part of mitigating bias is proactively
evaluating AI systems by analyzing their outputs for biases. Models can
be tested by measuring performance metrics such as false positive and
false negative rates separately for each subgroup. For instance,
significant performance disparities between groups like men and women
can reveal unfair biases. Ongoing monitoring across demographics is
necessary to detect unintended discrimination before AI systems
negatively impact people’s lives. Without rigorous evaluation of model
outputs, harmful biases can easily go unnoticed.</p>
<p><strong>Reducing toxicity in data aims to mitigate harmful biases in
AI, but faces challenges.</strong> <em>Toxicity</em> refers to harmful
content, such as inflammatory comments or hate speech. Models trained on
unfiltered text can absorb these harmful elements. As a result, AI
models can propagate toxic content and biases if not carefully designed.
For example, language models can capture stereotypical and harmful
associations between social groups and negative attributes based on the
frequency of words occurring together. Reducing toxicity in the training
data can mitigate some biases. For example, developers can use toxicity
classifiers to clean up the internet data, using both sentiment and
manual labels to identify toxic content. However, all of these
approaches still run into major challenges and limitations. Classifiers
are still subject to social bias, evaluations can be brittle and
unreliable, and bias is often very hard to measure.</p>
<p><strong>Trade-offs can emerge between correcting one form of bias and
introducing new biases.</strong> Bias reduction methods can introduce
new biases, as classifiers have social biases, evaluations are
unreliable, and bias reduction can introduce new biases. For example,
some experiments show that an attempt to correct for toxicity in
OpenAI’s older content moderation system resulted in biased treatment
towards certain political and demographic groups: a previous system
classified negative comments about conservatives as not hateful, while
flagging the exact same comments about liberals as hateful <span
class="citation" data-cites="Rozado2023treatment">[10]</span>. It also
exhibited disparities in classifying negative comments towards different
nationalities, religions, identities, and more.<p>
In summary, biases can arise at all stages of the AI lifecycle and
compound in complicated ways. A multifaceted approach is necessary,
combining development practices, technical strategies, and governance,
to detect and reduce harmful biases in AI systems.</p>
<br>
<br>
<h3>References</h3>
<div id="refs" class="references csl-bib-body" data-entry-spacing="0"
role="list">
<div id="ref-amazon_bias" class="csl-entry" role="listitem">
<div class="csl-left-margin">[1] J.
Dastin, <span>“Amazon scraps secret AI recruiting tool that showed bias
against women.”</span> [Online]. Available: <a
href="https://www.reuters.com/article/us-amazon-com-jobs-automation-insight-idUSKCN1MK08G">https://www.reuters.com/article/us-amazon-com-jobs-automation-insight-idUSKCN1MK08G</a></div>
</div>
<div id="ref-bolukbasi2016man" class="csl-entry" role="listitem">
<div class="csl-left-margin">[2] T.
Bolukbasi, K.-W. Chang, J. Zou, V. Saligrama, and A. Kalai, <span>“Man
is to computer programmer as woman is to homemaker? Debiasing word
embeddings.”</span> 2016. Available: <a
href="https://arxiv.org/abs/1607.06520">https://arxiv.org/abs/1607.06520</a></div>
</div>
<div id="ref-zhao2017men" class="csl-entry" role="listitem">
<div class="csl-left-margin">[3] J.
Zhao, T. Wang, M. Yatskar, V. Ordonez, and K.-W. Chang, <span>“Men also
like shopping: Reducing gender bias amplification using corpus-level
constraints.”</span> 2017. Available: <a
href="https://arxiv.org/abs/1707.09457">https://arxiv.org/abs/1707.09457</a></div>
</div>
<div id="ref-gilbert2022choices" class="csl-entry" role="listitem">
<div class="csl-left-margin">[4] T.
K. Gilbert, S. Dean, T. Zick, and N. Lambert, <span>“Choices, risks, and
reward reports: Charting public policy for reinforcement learning
systems.”</span> 2022. Available: <a
href="https://arxiv.org/abs/2202.05716">https://arxiv.org/abs/2202.05716</a></div>
</div>
<div id="ref-stray2021optimizing" class="csl-entry" role="listitem">
<div class="csl-left-margin">[5] J.
Stray, I. Vendrov, J. Nixon, S. Adler, and D. Hadfield-Menell,
<span>“What are you optimizing for? Aligning recommender systems with
human values.”</span> 2021. Available: <a
href="https://arxiv.org/abs/2107.10939">https://arxiv.org/abs/2107.10939</a></div>
</div>
<div id="ref-kross2013facebook" class="csl-entry" role="listitem">
<div class="csl-left-margin">[6] E.
Kross <em>et al.</em>, <span>“Facebook use predicts declines in
subjective well-being in young adults,”</span> <em>PloS one</em>.</div>
</div>
<div id="ref-krueger2020hidden" class="csl-entry" role="listitem">
<div class="csl-left-margin">[7] D.
Krueger, T. Maharaj, and J. Leike, <span>“Hidden incentives for
auto-induced distributional shift.”</span> 2020. Available: <a
href="https://arxiv.org/abs/2009.09153">https://arxiv.org/abs/2009.09153</a></div>
</div>
<div id="ref-zhang2018mitigating" class="csl-entry" role="listitem">
<div class="csl-left-margin">[8] B.
H. Zhang, B. Lemoine, and M. Mitchell, <span>“Mitigating unwanted biases
with adversarial learning.”</span> 2018. Available: <a
href="https://arxiv.org/abs/1801.07593">https://arxiv.org/abs/1801.07593</a></div>
</div>
<div id="ref-raji2020closing" class="csl-entry" role="listitem">
<div class="csl-left-margin">[9] I.
D. Raji <em>et al.</em>, <span>“Closing the AI accountability gap:
Defining an end-to-end framework for internal algorithmic
auditing.”</span> 2020. Available: <a
href="https://arxiv.org/abs/2001.00973">https://arxiv.org/abs/2001.00973</a></div>
</div>
<div id="ref-Rozado2023treatment" class="csl-entry" role="listitem">
<div class="csl-left-margin">[10] D.
Rozado, <span>“The unequal treatment of demographic groups by
ChatGPT/OpenAI content moderation system.”</span> [Online]. Available:
<a
href="https://davidrozado.substack.com/p/openaicms">https://davidrozado.substack.com/p/openaicms</a></div>
</div>
</div>