=Paper=
{{Paper
|id=Vol-2041/paper7
|storemode=property
|title=A Survey on Norwegian User's Perspective on Privacy in Recommender Systems
|pdfUrl=https://ceur-ws.org/Vol-2041/paper7.pdf
|volume=Vol-2041
|authors=Itishree Mohallick,Ozlem Ozgobek
}}
==A Survey on Norwegian User's Perspective on Privacy in Recommender Systems==
https://ceur-ws.org/Vol-2041/paper7.pdf
A Survey on Norwegian User’s Perspective on Privacy in
Recommender Systems
Itishree Mohallick and Özlem Özgöbek
Norwegian University of Science and Technology, Trondheim 7491, Norway
m.itishree@gmail.com
ozlem.ozgobek@ntnu.no
Abstract. In this digital era, there is ample research on the issue of privacy
concerns in recommender systems. Still, there remain many important research
questions which are yet to be answered concerning the topic. In one such at-
tempt, this survey is designed to study and understand the opinion of Norwe-
gian users as compared to the users from different nationalities regarding their
privacy concerns in recommender systems. This article analyses the survey re-
sults of Norwegian users’ privacy attitude over several aspects such as behav-
ioral preferences, privacy preferences, trust, ownership, and control. A compar-
ative study between the demographic differences demonstrates the influence of
demographics on individual user’s privacy opinion. Norwegian users are found
to be less concerned regarding their privacy in recommender systems. This arti-
cle concludes with a discussion where the aforesaid privacy aspects and their
interconnectivity are studied from the Norwegians’ and others’ point of view.
This opinion based research can help designers and researchers to understand
and mitigate user’s privacy concern while designing cutting age recommender
systems.
Keywords: Recommender Systems, Privacy Perception, Trust and Ownership.
1 Introduction
With the advent of World Wide Web, recommender systems have gained significant
importance. Most of the internet users must have come across recommender systems
during their internet usage. For example, Facebook suggests new friends for adding
into the existing friend list whereas LinkedIn suggests job offers, new connections,
news and interesting companies for its’s registered users. Advances in such modern
technologies which includes data collection, matching, and profiling for creating “us-
er profiles” to offer tailored products to the users have raised privacy concerns in
recommender systems.
Copyright held by the author(s). NOBIDS 2017
2
The conventional research approach in recommender systems focuses on the predic-
tion accuracy of various recommendation algorithms [1-3]. The prediction accuracy of
any recommender system partially constitutes the user experience. But, the perfor-
mance and accuracy of the prediction algorithms are primarily used for evaluating the
recommender systems. However, researching the user experience for such personalized
systems are found to be effective for evaluation of these user-adaptive systems in re-
cent years. The effectiveness and evaluation criteria of recommender systems are in-
vestigated from user’s perspective [4] as recommendation accuracy does not suffice for
being useful to the users [5]. The various user-centric concerns related to recommender
systems (i.e.; privacy concerns) can only be addressed effectively by studying the actu-
al opinion of real users.
Privacy in recommender systems is concerned with user information. Generally, us-
ers keep on worrying regarding their online privacy. Although many surveys conclude
the fact that users, in general, are concerned about their online privacy none of them
present a demographic study of this privacy concerns in recommender systems. In this
paper, we present the results of the survey which is basically designed to find out the
interesting and unique features related to users’ perception of privacy in recommender
systems with a focus on cultural differences of different nationals (Norwegian users
and users from other nationalities).
The objective of this paper is to investigate the opinion of users regarding recom-
mender systems; especially focusing on Norwegian user’s privacy behavior and opin-
ion while using various recommender systems. This user study was run with 100 peo-
ple from different nations where 26 of them were Norwegians. In this paper, the priva-
cy preferences of Norwegian users are presented in comparison with other nationals.
As a result, it is observed that users’ trust in the service provider and ownership of the
users’ own data are correlated. This, in return, reduces the privacy concerns of the
users. The paper is structured as follows: A brief background study related to user-
centric surveys and privacy risks in recommender systems is given in Section 2. The
interpretation and evaluation of the user study based on the key findings are presented
in Section 3. Section 4 includes a brief discussion providing the executive summary of
the survey results. Section 5 concludes the paper.
2 Related Work
Evaluating recommender systems is not an easy task as it involves both the system
and the users. Many different evaluation techniques are adopted in dissimilar ways to
evaluate the recommender systems [6]. These evaluation techniques are broadly clas-
sified into two types; system-centric and user-centric. The latter technique has been
discussed in detail in [6, 7] where the users interact with a recommender or multiple
recommenders in an online environment. The output data is collected based on the
user and system interaction. This interaction is carried out through either a preset
questionnaire or online surveys where users are required to provide their input. Exper-
iments involving real users are helpful in evaluating recommender systems effectively
than the offline experiment.
3
It is however important to look at user’s privacy concern as part of the user-centric
evaluation in recommender systems. In general, privacy in recommender systems is
multi-faceted which includes the recommender system itself, users and third parties
(any external entity involved in the process such as data brokers, other companies
where user data is outsourced from the parent company) [8, 9]. Hence, user-centric
research is similarly important as the system-centric research in such user-adaptive
systems because recommender systems are designed and developed to be used by the
end users. Evaluating recommender systems from user’s privacy perspective as in [10]
further helps in distinguishing the actual behaviors of users from their privacy prefer-
ences.
User’s privacy concern has been addressed from a different perspective such as us-
er’s personal traits, trust, the value of disclosure in many prior researches [11]. Trust in
the service providers has been long identified as one of the main influential characteris-
tics to reduce privacy worries of users in the online environment [12-14]. User control
is given much importance to influence (reduce) the user’s privacy concern by inducing
trust in the service providers.
User’s personal characteristics influence the information disclosure behavior of the
user and often contributes to individual user’s privacy perception [15]. Value of the
perceived benefit also determines user’s information disclosure behavior as the gained
benefits can overweight the risk factors involved with user’s personal information
disclosure [16, 17].
Prior researches have addressed the various privacy Laws and Regulations as an
impact to the user’s privacy behavior. Considerably a stronger privacy law such as the
European Union (EU) privacy Directive might reduce privacy concerns of EU users
than rest of the world [18]. International differences in the privacy laws and regulations
further influence user’s privacy perception.
User’s opinion regarding privacy hold a prominent place in decision making and in-
fluences the information disclosure behavior of the user [19]. Hence, the user-centric
comparative survey based on demographic may bring forth any interesting result re-
garding the user’s privacy perspective.
3 User Study
The main goal of this user-centric evaluation process is to understand the user’s opin-
ion concerning privacy and accessing the numerous factors which contribute to user’s
privacy concern in recommender systems. For the user study, an online survey is de-
signed to understand the behavioral approaches and privacy concerns among online
users. The outputs of the survey are beneficial for providing user-centered guidelines
or solutions in the said problem domain.
The online survey is conducted for a duration of 30 days and 100 responses from
16 nationalities are recorded. The aim of the user experience research is to gain ade-
quate knowledge from a group of people who have the preliminary understanding of
the personalized services. Hence, most of the respondents belong to the student and
professional networks. But a common diversity designed during the survey is to find
4
the opinion from different age groups and different nationalities. The users are asked
to complete a set of questionnaires referring to various aspects of user experience
related to recommender systems. It includes users’ impression of the usability of the
system, user awareness, privacy concerns of users, trust, ownership, behavioral pref-
erences and preferences for cross-domain recommendation.
The initial analysis of the survey results demonstrated that user’s privacy concerns
are a major issue and it directly impacts the recommender systems. Based on the re-
sults, the findings are divided into the following categories (i.e., behavioral prefer-
ences, trust, and ownership) which we hope that they help researchers and developers
to provide better privacy solutions in the recommender systems domain. The out-
comes of the survey are further analyzed for the Norwegian users against the non-
Norwegian users to find out similarities and differences.
3.1 Behavioral Preferences and Privacy Concerns
On the topic concerning user’s behavioral preferences and privacy, Norwegian users
are found to be more active in using the recommendation service daily. A whopping
62% of Norwegian users replied to have used the recommender system several times a
day proves the aforesaid fact. However, the preferences for using the recommendation
service do not influence directly the privacy behavior of every user. Although all the
participants have used the recommendation service at some point in time, respondents
who have asked for the service providers to view their own user profiles or other in-
formation are found to be 35%. User’s perception of recommender systems following
laws and regulations are found to be undermined. To understand user’s behavior from
the demographic point of view, a further analysis has been done for Norwegian users
versus non-Norwegian users.
An interesting result has been found was that the non-Norwegian users are more
privacy concerned than the Norwegian users whereas the Norwegian users most fre-
quently use the recommendation services compared to the non-Norwegian users. In
Fig. 1, the differences between the privacy concerns among Norwegian users and
non-Norwegian users is shown. Here we interpret that the users requesting to see the
user profiles are more privacy aware or concerned about their personal information.
As it can be seen in the figure, while replying to a ‘Yes’ or ‘No’ type question, only
28% Norwegian users have replied that they have requested their user profile data
whereas 38% non-Norwegian users have requested to view their user profile data.
5
Fig. 1. Privacy Privacy concerned (a) Non-Norwegian (b) Norwegian users
In the survey, a group of questions whose objective is to determine the most preferred
recommendation domain from a group of recommendation services (e.g., news, mu-
sic, movies, books, shopping, and tourism) were asked. In Table 1, domain dependent
interests of users to get recommendations are shown. According to the table, the most
interesting domain that users would like to get recommendations was music. Howev-
er, news was the least preferred recommendation domain for all the users. Norwegian
users are found to be less interested in news recommendation as compared to the non-
Norwegian users by giving an average rating of 3.92 out of 10.
Table 1. User’s average rating (1-10) for different recommendation domain
Recommendation domain Norwegian Non-Norwegian
Music 5.88 6.66
Movies 5.42 6.31
News 3.92 5.17
Books 5.57 6.09
Other products 3.96 5.60
Both the Norwegian and non-Norwegian users are equally found to be uncertain if the
recommender systems are following the existing privacy laws and regulations. Anoth-
er question based on user’s perception on “systems violate privacy” draws similar
response from the users. In a scale from 1 to 10 ratings, both the Norwegian and non-
Norwegian users expressed a similar concern by giving an average approximate rating
of 6 for this question.
6
3.2 Trust and Privacy Concerns
Trust and privacy have been interlinked in recommender systems. User’s trust can be
violated in many ways such as exposure, sabotage, and bias [14]. A part of our user
survey demonstrates the link between user trust and privacy in recommender systems.
For instance, when users were asked if they would prefer a single user profile in-
stead of having multiple user profiles across different recommender system domains
like movies, music or news, more than half of the users (53% approx.) opted out by
saying “Not at all”. Exposure of personal data through sharing user profiles is found
to be a concern for both Norwegian and non-Norwegian users whereas 46% Norwe-
gian users chose not to share their user profiles among multiple domains which is
given in Fig. 2. In a follow-up question, it is found that added trust reduces the priva-
cy concern among users and more users are willing to share their user profile across
applications with trusted service providers. When the service provider is trusted, only
36% users refused to share their user profiles. It has been observed from the above
trend that added trust with the service provider increased the willingness of 17% users
to avail the service by allowing their profiles to be shared across applications. The
same trend has been observed for the Norwegian users where the denial rate has
dropped from 46% to 38% where the service provider is a trusted one. The link be-
tween user trust and exposure risk is clearly visible in Fig. 3.
Fig. 2. Sharing user profiles across applications with any service providers (Norwegian versus
non-Norwegians)
7
Fig. 3. Sharing user profiles across applications with a trusted service provider (Norwegian
versus non-Norwegians)
One of the important results we got is that the user trust for a service provider can be
established by allowing the users to control their personal data, through privacy
policies, and by followings privacy guidelines. In the survey, most of the users
expressed their concerns regarding to the service providers seeking the permission
before using personal data can build user trust for the concerned service providers.
Hence, user trust is found to be a primary factor from the survey results for reduc-
ing the privacy concerns of any user. In addition, user trust can motivate the user for
using the services of a trusted provider and increase the user’s willingness to share
their personal information (user profiles) with the service providers.
3.3 Ownership and Privacy Concerns
Ownership or control of user data plays a very crucial role in information privacy.
One of the basic privacy requirement for any user is to have a minimal level of user
control over their own data which is critical to the level of privacy concern experi-
enced by these users [20].
The survey results convey the concept of users’ ownership over their data from the
privacy perspective. By ownership of the data, the users are supposed to gain control
over their data by being able to modify, access or delete their personal data (stored in
the user profile) as and when they wish. Ownership over personal data makes the
respondent less concerned about privacy in recommender systems, increases the trust
for the service provider, and encourages the disclosure of profile data across applica-
8
tions and frequent system usage. Almost 88.6 % of Norwegian users (23 out of 26
respondents) as compared to 59.45 % of non-Norwegian users (44 out of 74 respond-
ents) replied that ownership over their data makes them feel more secure regarding
their online privacy in recommender systems. The users could select multiple options
under this category of questions. Hence, many users (both Norwegian and non-
Norwegian) have also stated that ownership can enhance their trust for the service
providers. In addition, 30.76 % of Norwegian users (8 out of 26 respondents) as 27.02
% of non-Norwegian users (20 out of 74 users) have shown their interest in sharing
their user profiles across multiple domains if they are given the ownership over their
own data.
While studying users’ opinion regarding ownership, 88.6% Norwegian users (23
out of 26 respondents) stated that the access to modify and delete their own data pro-
vides them true control regarding their personal data. However, 78.37% non-
Norwegian users (58 out of 74 respondents) selected the above-said options in the
context of true ownership over user’s own data. Moreover, users would prefer to be
asked for their consent before the data is being shared. This trend is evident as 76.92
% Norwegian users and 78.37 % non-Norwegian users (58 out of 74 respondents)
opted “I decide how my data is shared”. Equal responses are received from the non-
Norwegian users regarding ownership of their data as they would prefer to be allowed
to modify and delete their data as well as asked for their consent before the data is
shared.
Fig. 4. Importance of owning user’s own data
The results regarding importance of owning user data in recommender systems is
shown in the below Fig. 4 for the Norwegian users and non-Norwegian users. Owner-
ship of the user data is found to be more important for Norwegian users (see Fig. 4).
9
4 Discussion
The outcomes of this survey demonstrate that all the users (100%) are using recom-
mendation services in various frequencies as all the participants stated availing the
recommendation service. However, 61.53% of Norwegian users access the recom-
mendation services by using it several times a day, while only 41.81 % of Non-
Norwegian users have the same habits. This can also be interpreted as Norwegians are
the most aware user group about existing online recommender systems. Irrespective
of the popularity of the recommendation service, there is an increasing concern
among the users related to privacy of their personal data in the recommender systems.
While most of the users are concerned regarding privacy in recommender systems,
a limited number of users really tried to ask and learn more about their personal data
shared with these personalized service providers. An interesting fact came into sight
as the survey results shown that the Norwegian users are less concerned regarding
privacy in recommender systems than the rest of the users from different nationalities.
Most of the users from all nationalities lack in knowledge regarding the privacy
laws and regulations whereas 30.76% Norwegian users think that recommender sys-
tems do not adhere to the existing regulations. Most users believe that recommender
systems violate their privacy through collecting more data than approved and by shar-
ing the data with any external entities. Most of the users believe that their personal
information is being exploited. Users have shown less interest in news recommenda-
tion as compared to other domains such as movie, music, books, shopping, and tour-
ism. However, movie, music, and books are found to be most preferred by the users.
Interestingly, news and tourism are two domains where the users are less interested in
receiving any recommendation. Majority of participants not at all prefer to share their
user profiles across domains, although a common profile for multiple domains has its
advantages, for example, it is less time consuming while getting personalized ser-
vices. Whereas certain users prefer a common profile with adequate user control.
Trust is an important characteristic which can influence user’s privacy attitude. Users
prefer to share their information with a trusted service provider. With trust, more us-
ers are ready to share their personal information across the domain. User control and
user consent regarding the data usage are the two key factors which can build trust for
the service providers although the other options are equally relevant. User control
increases trust and reduces privacy concerns for the users. User preferences are diffi-
cult to predict under different environment. However, a common trend for positive
preferences is observed for book recommendation from the user behavior whereas
news recommendation is found to be not that much desired. Ownership of the data
can provide more user control over their online data. Ownership of the user data can
reduce the privacy concerns of users. Most of the users believe to gain complete con-
trol (modification, deletion and usage control) over their data can provide them with
actual ownership.
In the end, users detailed comments revealed some explanations for the outcome of
the study. Most of the user opinion, in the very last open question, indicated to the
user’s information privacy concern from three basic angles; data collection, user con-
trol, and awareness. The received opinion from users clearly states that how data col-
10
lection and the control over individual data is undervalued in the user privacy scenar-
io. Users are found to be concerned about the received benefit versus risk while re-
ceiving the recommendation services. Another concern reveals that online service
provider’s profits outweigh user privacy in practice. These user opinions if considered
can certainly contribute to getting a robust recommendation while preserving the pri-
vacy of users.
5 Conclusions
The survey results based on the influence of demographic information such as nation-
alities (Norwegian users) on user’s privacy opinion is presented in this paper. A com-
parative study between the Norwegian users and rest other respondents establishes the
two-different perspective of their privacy opinion mainly focusing on behavioral pref-
erences, trust, and ownership.
The survey results demonstrated here is unique and has its merits in many aspects.
The Norwegian users are found to be less privacy sensitive than rest of the users. In
contrast, Norwegian users are found to be more concerned regarding ownership and
control of their online data in recommender systems than the non-Norwegian users.
In this exploratory study, the received responses relied solely on user’s assumptions
and imaginations as given by the survey description. The respondents might have
evaluated or responded differently if they could interact with a real recommender
interface. Their privacy concerns over several topics such as cross-recommendation,
ownership or trust might be hypothetical or depended on a previous privacy encoun-
ter. Therefore, a future research would be helpful to implement a real user interface
based on our survey findings and later measuring the privacy concerns of Norwegian
users than the rest of the users. Another future research perspective can consider the
impacts of the existing privacy laws and regulations on users’ privacy perceptions
from different nations (since privacy laws and regulations differ from country to
country).
6 Acknowledgement
This work is a part of the master thesis which is supported by the NTNU SmartMedia
program on news recommendation.
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