Table 2.

Research goals, research objectives and extracted features from SO posts.

Goal	Research question	Features	Data analysis method(s)
Research field analysis (g1)	[RQ1.1] Did the evolution of COVID-19 pandemic trigger corresponding knowledge-sharing activity in SO and how has this phenomenon evolved over time?	SO metadata ($d,vi,vo,na,c,sn$)	Descriptive statistics, Statistical Hypothesis Test (chi-square test of independence, Mann–Whitney)
	[RQ1.2] Which are the characteristics of COVID-19 knowledge-sharing activity in SO?
Identification of technology advances and associated problems (g2)	[RQ2.1(a)] Which technologies are more popular in COVID-19 software development and how are these associated to each other?	List of tags ($tg$)	Graph Theory (Association Rule Graph)
	[RQ2.1(b)] Which technologies present more difficulties in COVID-19 software development?	Time elapsed until the first answer to be posted ($t=d-ad$)	Survival Analysis (Kaplan–Meier curves)
	[RQ2.2] Which topics are more popular in COVID-19 software development?	Textual information ($t,b$)	Latent Dirichlet Allocation