“Am I doing it better?” Conveying the message to athletes Simon Fothergill, Ph.D. student Digital Technology Group, Computer Laboratory, University of Cambridge DTG Monday Meeting, 21 st February 2010, FW26

Baking a cake is a complex process… NaHCO 3 + H + → Na + + H 2 O + CO 2 CO 2 fills gluten structure Proteins uncurl to re-enforce structure egg

…or not!

Athletes suffer from data overload

There are different forms of feedback

Useful simplification of feedback Importance of aspects Events Raw kinetics Similarity Importance of aspects Events Similarity Coaches vocabularyCoaching session with basic feedback Rowing community survey

Coaching continues to develop Feedback – efficient and safe training and performance Self assessment – requires expertise, bias Automation – fidelity, quantity, reliability, objectivity, availability Coaches teach machines the human touch

Judgement of similarity Applications Quality ~ distance from target Consistency ~ quality, fatigue Takes various forms Continuous Inter-athlete Intra-athlete Overall Performance Individual aspect (handle trajectory) Handle trajectories from athletes with different levels expertise

Capturing expert opinions on forms of similarity

Evaluation of well-known similarity metrics d2 d1 Metric d1 < d2 Performance 1 Performance 2 Performance 0 Metric score += ? Expert coaches

Accuracy approaches some expert coach Inter-athlete Intra-athlete Overall performanceIndividual aspect

Summary of results Overall Performance Inter-athlete: Duration >= 61.0% of some coach Intra-athlete: Euclidean distance >= 71.1% of some coach Individual Aspect Inter-athlete: DTW >= 54.0% of some coach Intra-athlete: Duration >= 43.8% of some coach Algorithms are more useful for coarser judgements

Combining metrics can be complementary

Characterising trajectories

Acknowledgements GB Rowing CUWBC Jesus College Boatclub Jesus College BoatClub Trust Cantabs Boatclub ISEA DTG Computer Laboratory SeSAME Jesus College Rainbow group Andy Hopper George Coulouris Rob Harle Andrei Bejan Alan Blackwell Sean Holden Brian Jones Marcelo Pias Joe Newman Andy Rice Salman Taherian Richard Gibbens Andrew Lewis