1. 5/22/19 1Demetris Trihinas
trihinas.d@unic.ac.cy
1ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
Machine Learning
Panel Opening Comments
Demetris Trihinas
Department of Computer Science
AILab @ University of Nicosia
trihinas.d@unic.ac.cy
2. 5/22/19 2Demetris Trihinas
trihinas.d@unic.ac.cy
2ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
Full-Time Faculty Member
University of Nicosia
“Designing and developing scalable and self-adaptive tools for data
management, exploration and visualization”
@dtrihinas
http://dtrihinas.info
https://ailab.unic.ac.cy/https://www.slideshare.net/DemetrisTrihinas
3. 5/22/19 3Demetris Trihinas
trihinas.d@unic.ac.cy
3ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
What is NOT Machine Learning
• Any question you can ask and get an –immediate and
concrete– answer (e.g., database, spreadsheet).
• How many sofas models are currently in stock?
• How many sofas did we sell in Germany last month?
• Which of our customers bought a sofa worth more than 500
euros this quarter?
4. 5/22/19 4Demetris Trihinas
trihinas.d@unic.ac.cy
4ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
The Machine Learning Process
Data and
Labels
Feature
Engineering
ML
Algorithm
Bike
Car
Bike
< 2, 170, 35, 169, 51, 38, …>
< 2, 119, 28, 210, 52, 02, …>
Car
<4, 13, 157, 90, 178, 145, …>
<4, 12, 170, 82, 193, 145, …>
wheels
Training
Testing
Data
Feature
Engineering
Inferencing
Statistical
Model
<4, 18, 200, 64, 170, 141, …> It’s a… Car
Finding ”patterns” from features
! = #(%, ')
5. 5/22/19 5Demetris Trihinas
trihinas.d@unic.ac.cy
5ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
ML Modeling is an Approximation...
Feature
Engineering
ML
Algorithm
Training
Testing
Data
Feature
Engineering
Statistical
Model
<4, 18, 200, 64, 170, 141, …>
<3, 22, 23, 31, 101, 205, …>
Data and
Labels
Inferencing
It’s a Car I’m 0.88 sure
It’s a Car I’m 0.71 sure
6. 5/22/19 6Demetris Trihinas
trihinas.d@unic.ac.cy
6ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
It’s Also Called “Learning” Because…
Feature
Engineering
ML
Algorithm
Training
Testing
Data
Feature
Engineering
Statistical
Model
<4, 18, 200, 64, 170, 141, …> It’s a… Car, 0.88
<3, 22, 23, 31, 101, 205, …> It’s a… Car, 0.71
<3, 22, 23, 31, 101, 205, …> It’s a… tricycle, 0.93
Data and
Labels
Evaluate
and
RetrainInferencing
8. 5/22/19 8Demetris Trihinas
trihinas.d@unic.ac.cy
8ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
Training is of Utmost Importance
• More training data is good but too much leads to overfitting
(irrelevant details are modeled).
• Algorithms are not racist, do not hold prejudice or apply
stereotypes… yes, but what happened to Amazon?
Memorizing the answers is NOT Learning
9. 5/22/19 9Demetris Trihinas
trihinas.d@unic.ac.cy
9ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
Beware of the “Trainer”…
https://www.businessinsider.com/amazon-built-ai-to-hire-people-discriminated-against-women-2018-10
10. 5/22/19 10Demetris Trihinas
trihinas.d@unic.ac.cy
10ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
Data Preprocessing
• Preprocessing significantly increases ML performance
and result quality.
• Is 1% more error tolerable if computation “promises”
to run for 10min instead of 5 hours?
• Data Reduction –remove
insignificant model dimensions.
• Data Cleaning –remove
incomplete and “dirty” data.
Do not “influence” result
11. 5/22/19 11Demetris Trihinas
trihinas.d@unic.ac.cy
11ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
What is YOUR Role?
• Ask good questions – a model is based on a hypothesis.
• Provide training data – BEWARE training can lead to bias.
• Assess the quality of results – retrain let the model “learn”.
• TEST, TEST and TEST again.
The Ability Matrix
Insights are generated
by humans not
machines!
12. 5/22/19 12Demetris Trihinas
trihinas.d@unic.ac.cy
12ACCA ML Panel| Nicosia, May 2019
Department of
Computer Science
Questions?
Demetris Trihinas
Department of Computer Science
AILab @ University of Nicosia
trihinas.d@unic.ac.cy