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users for high compliance, persuasive design princi-
ples that are characterized by visually highlighting re-
gional products with short delivery routes or collec-
tive orders, as well as AI-supported fitting tools and
chat bots that automatically measure clothing sizes
and point out environmentally friendly delivery op-
tions, customers are encouraged to shop more con-
sciously – in the sense of a traffic shift, traffic avoid-
ance and traffic optimisation.
Through the active participation of the practical
partners Julius Meinl am Graben, kauftregional and
ZERUM, the innovative add-ons can be tested com-
prehensively and practically for different objectives,
target groups and different product groups in real op-
erations over several months. In addition, the inte-
gration of the innovative logistics service Green to
Home from logistics partner ERIVE makes it possible
to analyze the entire process between online shop op-
erators, online end consumers, and package delivery
service providers. Thus, this holistic approach gen-
erates new and in-depth insights into the acceptance,
suitability and impact of innovative interventions in
online shops.
Non-fitting garments are also a known factor to
strongly drive returns (Kristensen et al., 2013; Singh,
2015). To obtain precise body measurements, we de-
veloped a Fitting Tool in cooperation with partner
ZERUM. The Fitting Tool is an Android app that runs
on a small subset of mobile phones with active depth
sensing cameras. Due to the ability of such cameras
to exactly measure distances it was possible to rapidly
develop a prototype app to obtain body measurements
directly from depth images, using a pretrained body
pose keypoint detector.
In this paper we focus on reducing returns, both
by characterizing rules and by obtaining precise body
measurements using the Fitting Tool. We initially de-
scribe our results on using understandable machine
learning to analyze reasons for returns. In this project,
only ZERUM tracked and expressed concerns with
high returns, so we focus on its returns data. The anal-
ysis follows (Seewald et al., 2019) and also uses the
modified rule learning algorithm presented there.
Concerning the Fitting Tool, we first present an
algorithm to exactly measure body sizes from depth
camera images and body pose estimates and evaluate
its accuracy on a small set of persons. We then use
a subset of these measurements to determine T-shirt
sizes using a standard size table as well as machine
learning algorithms.
2 RELATED RESEARCH
Zalando Corporate (2023) introduced a new feature in
their app that measures body shape by one front and
one side photo of a person in tight-fitting clothes. It
is based on technology by company Fision which was
acquired by Zalando in 2020. Processing is locally
on the smartphone and photos are deleted afterwards.
The exact measurements are then used to search for
fitting clothes. Currently, only women’s tops – includ-
ing dresses – can be searched for. Contrary to our ap-
proach, their approachs works on any smartphone and
does not require special sensors. However, no quan-
tative data on the precision of the obtained measure-
ments were reported and the integrated search is likely
optimized to deal with the expected inaccurate mea-
surements. The requirement for tight-fitting clothes is
something that our system also needs as depth cam-
eras cannot see through clothes.
Singh (2015) analyzed reasons for returns within
Indian online market Flipkart, where mainly wom-
ens’ garments are sold directly by the manufacturers.
Apart from a detailed analysis of returns reasons they
also provided a minimal set of measurements for size
tables to reduce returns.
1
Simply changing the shown
size tables for nine manufacturers according to his
recommendations reduced returns dramatically: An
average reduction of absolute returns rate of 9% was
reported with a maximum of 46% – so manufacturers
saw their returns rate at best almost halved. They also
provided an analysis of returns reasons due to prod-
uct quality issues which were also a major cause for
returns within this online market, albeit less relevant
for our project.
Kristensen et al. (2013) present TrueFit, a sys-
tem to determine precise body measurements which
can reduce returns by up to 30%. However it re-
quires much effort by potential customers. TrueFit
works by combining extensive information provided
by customers on their height, age, weight as well as a
set of previously bought fitting clothes with manufac-
turer, model type and given size to determine best fit.
While it therefore tries to compensate both customer
and manufacturer bias, in its present form it ignores
body size temporal drift (i.e. changes in body size
over time).
Toktay (2003) analyzed different models to pre-
dict returns via synthetic data. They differentiated be-
tween modelling via periodical data where only the
number of sold and returned products is known (i.e.
1
Minimal set of measurements: breast width, waist cir-
cumference, shoulder circumference, sleeve diameter at
3
4
height; provide at least UK, US and EU-Sizes and at least
S,M,L,XL,XXL for simple sizes.
Climate-Friendly Online Shopping Within the Green eCommerce Project: A Fitting Tool to Determine T-Shirt Sizes Using Active Depth
Sensing
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