This work has been partially funded by projects PID2020-113462RB-I00 (ANIMALICOS), granted by Ministerio Espanol de Economia y Competitividad; projects P18-RT-4830 and A-TIC-608-UGR20 granted by Junta de Andalucia, and project B-TIC-402-UGR18 (FEDER and Junta de Andalucia).During the recent COVID-19 pandemic, people were forced to stay at home to protect
their own and others’ lives. As a result, remote technology is being considered more in all aspects
of life. One important example of this is online reviews, where the number of reviews increased
promptly in the last two years according to Statista and Rize reports. People started to depend more
on these reviews as a result of the mandatory physical distance employed in all countries. With no
one speaking to about products and services feedback. Reading and posting online reviews becomes
an important part of discussion and decision-making, especially for individuals and organizations.
However, the growth of online reviews usage also provoked an increase in spam reviews. Spam
reviews can be identified as fraud, malicious and fake reviews written for the purpose of profit
or publicity. A number of spam detection methods have been proposed to solve this problem. As
part of this study, we outline the concepts and detection methods of spam reviews, along with
their implications in the environment of online reviews. The study addresses all the spam reviews
detection studies for the years 2020 and 2021. In other words, we analyze and examine all works
presented during the COVID-19 situation. Then, highlight the differences between the works before
and after the pandemic in terms of reviews behavior and research findings. Furthermore, nine
different detection approaches have been classified in order to investigate their specific advantages,
limitations, and ways to improve their performance. Additionally, a literature analysis, discussion,
and future directions were also presented.Spanish Government PID2020-113462RB-I00Junta de Andalucia P18-RT-4830
A-TIC-608-UGR20
B-TIC-402-UGR18European Commission B-TIC-402-UGR1
