Essays on the interaction between users and information systems

The role of information systems has evolved from providing decision support into enabling the majority of our daily operations, and the way users interact with information systems has changed dramatically as a result. The goal of this dissertation is to study phenomena that stem from the close interaction between users and information systems using empirical methodologies.

The first essay of this dissertation focuses on the issue of sentiment manipulation. We show that strategic players might be incentivized to manufacture content on social media platforms and opinion forums, in the context of the movie industry. We then identify unusual patterns on Twitter that are consistent with sentiment manipulation.

We study the effectiveness of social media advertising in the second essay. Advertisers on popular social media platforms such as Facebook are able to publish ads with popularity and social information. We design and conduct a randomized field experiment to study the extent to which these types of information have an effect on ad performance.

In the third essay we study how individuals might be biased toward contents that appear to be written more politely. We use data from an online question answering platform, StackExchange, to show that an individual who posts a question on the platform tends to prefer polite answers to clear answers.