World Cup Women’s 10k Classic Nordic Ski Race - Splits

Simple linear regression
Correlation
Randomized block ANOVA
Times and ranks of skiers taken at four different distance points (1.3, 4.3, 7.5, and 10k) in a 10k classic race in Trondheim, Norway.
Authors
Affiliation

Abigail Smith

St. Lawrence University

Robin Lock

St. Lawrence University

Published

May 16, 2024

Module

Please note that these material have not yet completed the required pedagogical and industry peer-reviews to become a published module on the SCORE Network. However, instructors are still welcome to use these materials if they are so inclined.

Introduction

The International Ski and Snowboard Federation (FIS), organizes and records a series of events such as the World Cup which exists for all disciplines of FIS such as Nordic Skiing. World Cup races occur every weekend between January and March, with events hosted in different countries. These events consist of multiple different races, held in different disciplines and distances. Nordic skiing is split up into two different techniques, classic and skate, all race weekends have a mixture of skate and classic technique races. The race in this dataset is a womens’ 10k classic race set in Trondheim, Norway. In long distance pieces like 10ks there is often a lot of discussion about pacing. Racers’ times are recorded at different distance intervals throughout the course. It is interesting to look at how well racers’ times at different distances predict their rank at the end of the race. For example, do the racers who have top times at an early distance have good ranks at the end of the race?

Preliminary video ideas

By the end of this activity, you will be able to:

  1. Fit a linear regression model.

  2. Assess a correlation.

  3. Look at and ANOVA model for a randomized block design

To be written

Data

Each row of the dataset represents a skier in the womens’ 10k classic ski race in Trondheim. There are 61 racers in the dataset and 24 variables. The “splits” record rank, time, and sped at four points in the race 1=1.3 km, 2=4.3 km, 3=7.5 km, and 4=10 km (finish).

Download data: Nordic10K_ski_speeds.csv

Variable Descriptions
Variable Description
Bib The bib number of the skier, which also represents the order they started in.
Name The name of the skier.
NSA The nation a skier is representing.
Rank1 The rank or placement of skiers at the first distance interval.
Time1 The skier’s time at the first distance interval, measured in minutes.
Diff1 The difference of time between each skier and the first place racer, at the first distance interval, measured in seconds.
Dist1 The distance of the first interval, measured in kilometers.
Rank2 The rank or placement of skiers at the first distance interval.
Time2 The skier’s time at the first distance interval, measured in minutes.
Diff2 The difference of time between each skier and the first place racer, at the second distance interval, measured in seconds.
Dist2 The distance of the second interval, measured in kilometers.
Rank3 The rank or placement of skiers at the third distance interval.
Time3 The skier’s time at the third distance interval, measured in minutes.
Diff3 The difference of time between each skier and the first place racer, at the third distance interval, measured in seconds.
Dist3 The distance of the third interval, measured in kilometers.
Rank4 The rank or placement of skiers at the fourth distance interval.
Time4 The skier’s time at the fourth distance interval, measured in minutes.
Diff4 The difference of time between each skier and the first place racer, at the fourth distance interval, measured in seconds.
Dist4 The distance of the fourth interval, measured in kilometers.
Event The FIS code assigned to the event.
Speed1 Speed (km/min) over the first split (1.3K)
Speed1 Speed (km/min) over the second split (1.3K-4.3K)
Speed1 Speed (km/min) over the third split (4.3K-7.5K)
Speed1 Speed (km/min) over the fourth split (7.5K-10K)

A revised version of the data set stacks the speeds into a single column with another variable identifying the split and a third with the skier’s name. This version has 236 rows for the three variables.

Download data: Stacked_Nordic10K_ski_speeds.csv

Variable Descriptions - stacked version
Variable Description
Speed Speed over the split (km/minute)
SpeedInterval Spped1, Spped2, Spped3, or Speed4
Name The name of the skier

Data Source

Trondheim 4th World Cup Stage - Women’s Interval Start 10.0 km Classic results via the FIS website at https://live.fis-ski.com/cc-2257/results-pda.htm

Materials

Class handout

Class handout - Key

To Be Written …