Plot to emphasize the lack of correlation between the two. This confirms that users really do appear to play different roles in the community, with some initiating relatively often but not replying much, and others replying readily while initiating but little.5.2. Predicting the effects of introducing a new userWe now consider a scenario where a new user joins the network and becomes the neighbour of any three existing community RRx-001 price members that we TGR-1202MedChemExpress TGR-1202 choose. Which three community members should our new user befriend? For illustration, we explore four possible choices: (i) (ii) (iii) (iv) Befriend the three users with the most positive sentiment Befriend the three users with the most negative sentiment Befriend the three users with the highest reply probabilities Befriend the three users with the lowest reply probabilitiesFor the purposes of this example, we assume that our user will be vocal but with sentiment matched to the prevailing sentiment of the existing community: the new user’s initiation (resp. reply, propagation) probability is set to three times the maximum initiation (resp. reply, propagation) probability found in the existing community. Also, the new user’s baseline sentiment level is set to the existing community sentiment level. Figures 16, 17, 18 and 19 show how our four choices of neighbours affect four aspects of the community: the activity level, the standard deviation (variability) of the daily activity levels, the14 standard deviation of no. messages sent per day (simulated data) 12 10 8 6 4rsos.royalsocietypublishing.org R. Soc. open sci. 3:…………………………………………10 15 20 25 30 standard deviation of no. messages sent per day (real data)Figure 14. The standard deviation (variability) of the daily count of messages sent by each user, in the real data and averaged over 500 simulation runs.0.0.reply probability0.0.0.0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 0.0007 0.0008 0.0009 0.0010 initiation probabilityFigure 15. Comparing the initiation probability and reply probability for each agent.sentiment level and the standard deviation (variability) of the daily sentiment levels (all averaged over 100 simulation runs and using (MC)). The results highlight again the role of network structure: if our new user befriends the three most positive users, then the community sentiment goes up, and if he befriends the three most negative users, the community sentiment goes down. Similarly, choosing the users with the highest or lowest reply probabilities as neighbours has a markedly different effect on activity levels. Validating our model’s predictions about the effects of new users on real data is beyond the scope of this paper; it is a challenging research task in itself and is left as future work.45 increase in activity level (messages sent per day) 40 35 30 25 20 15 10 5rsos.royalsocietypublishing.org R. Soc. open sci. 3:…………………………………………neighbours are three users with most positive sentimentneighbours are three users with most negative sentimentneighbours are three users with highest reply probabilitiesneighbours are three users with lowest reply probabilitiesFigure 16. The effect on the increase in community activity level of four options for the neighbours of the newly introduced user.standard deviation of daily commumity activity level (no. messages sent) 36 35 34 33 32 31 30unmodified model communityneighbours are neighbours are neighbours are three users with three users.Plot to emphasize the lack of correlation between the two. This confirms that users really do appear to play different roles in the community, with some initiating relatively often but not replying much, and others replying readily while initiating but little.5.2. Predicting the effects of introducing a new userWe now consider a scenario where a new user joins the network and becomes the neighbour of any three existing community members that we choose. Which three community members should our new user befriend? For illustration, we explore four possible choices: (i) (ii) (iii) (iv) Befriend the three users with the most positive sentiment Befriend the three users with the most negative sentiment Befriend the three users with the highest reply probabilities Befriend the three users with the lowest reply probabilitiesFor the purposes of this example, we assume that our user will be vocal but with sentiment matched to the prevailing sentiment of the existing community: the new user’s initiation (resp. reply, propagation) probability is set to three times the maximum initiation (resp. reply, propagation) probability found in the existing community. Also, the new user’s baseline sentiment level is set to the existing community sentiment level. Figures 16, 17, 18 and 19 show how our four choices of neighbours affect four aspects of the community: the activity level, the standard deviation (variability) of the daily activity levels, the14 standard deviation of no. messages sent per day (simulated data) 12 10 8 6 4rsos.royalsocietypublishing.org R. Soc. open sci. 3:…………………………………………10 15 20 25 30 standard deviation of no. messages sent per day (real data)Figure 14. The standard deviation (variability) of the daily count of messages sent by each user, in the real data and averaged over 500 simulation runs.0.0.reply probability0.0.0.0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 0.0007 0.0008 0.0009 0.0010 initiation probabilityFigure 15. Comparing the initiation probability and reply probability for each agent.sentiment level and the standard deviation (variability) of the daily sentiment levels (all averaged over 100 simulation runs and using (MC)). The results highlight again the role of network structure: if our new user befriends the three most positive users, then the community sentiment goes up, and if he befriends the three most negative users, the community sentiment goes down. Similarly, choosing the users with the highest or lowest reply probabilities as neighbours has a markedly different effect on activity levels. Validating our model’s predictions about the effects of new users on real data is beyond the scope of this paper; it is a challenging research task in itself and is left as future work.45 increase in activity level (messages sent per day) 40 35 30 25 20 15 10 5rsos.royalsocietypublishing.org R. Soc. open sci. 3:…………………………………………neighbours are three users with most positive sentimentneighbours are three users with most negative sentimentneighbours are three users with highest reply probabilitiesneighbours are three users with lowest reply probabilitiesFigure 16. The effect on the increase in community activity level of four options for the neighbours of the newly introduced user.standard deviation of daily commumity activity level (no. messages sent) 36 35 34 33 32 31 30unmodified model communityneighbours are neighbours are neighbours are three users with three users.
