## 3 Experimental Results
### Results  
The parameters listed in the previous section were used to compare effectiveness of different recommendation layouts--horizontal vs. vertical. As a measure for effectiveness approximation, time of mouse pointer being located inside recommending interfaces was used. Due to the task given to participants as well as general study construction, this measure was selected as the most suitable one for comparing recommending interfaces. It  
Figure 1: Simplified layouts of e-commerce websites in the study (recommendation zones in grey): Agito.pl, Komputronik.pl, Electro.pl, Morele.net, Merlin.pl.  
was used together with measures related to various physical attributes of the product page. Since mouse position is highly correlated with eye gaze, especially when a user is actively browsing and scanning the page, thanks to being able to track the position with ECPM, we could measure user interest in particular parts of the page, especially recommending zones.  
The attractiveness of particular recommending interfaces resulting from analysis of data collected with the help of our ECPM tool is presented in Table 2 in the form of interest indicators, which are described in Section 3.2. The average time of mouse pointer being positioned on recommended items was higher for vertical layout than horizontal layout for three shops: Electro.pl, Agito.pl, and Merlin.pl, while it was the opposite for Morele.net. This may have resulted from the fact that there were more horizontal recommending zones than vertical ones in this particular store's layout (two horizontal zones versus one vertical).  
Another parameter which expresses the interest level in presented recommendations relative to page length is _rel_recommended_time_recommended_length_. For all four shops, vertical recommendation zones attracted more, or much more, attention compared to horizontal ones. In the case of Electro.pl, interest in vertical recommendations measured as the parameter mentioned was 116%, while for other three shops it was 20.3 to 23.1%.  
Cursor activity time over recommendation interface measured in relation to total page time (_rel_recommended_time_page_time_) as well to tab activity time (_rel_recommended_time_tab_active_) and user activity time (_rel_recommended_time_user_active_) also proved higher interest in vertical recommendation interfaces compared to horizontal ones in all shops but one (Morele.net).  
The number of pages where users significantly moved the cursor over recommending interfaces (registered _prod_recommended_time_) compared to the same event over product review sections (_prod_review_time_) was in favor of recommending interfaces (Table 3). They attracted customers more often in all stores, and Morele.net gained the highest advantage of 386%.  
\begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline \hline
**Store** & _prod\_recomm_** & _pred\_recommended\_time_ & _rel\_recommended\_time_ & _rel\_recommended\_time\_ & _rel\_recommended\_time\_ & _rel\_recommended\_time\_ & _rel\_recommended\_time\_ \\ _rc\_layout_ & _merged\_time_ & _document\_length_ & _document\_length_ & _recommended\_time_ & _page\_time_ & _user\_active_ & _tab\(tab\quad\)_table\_active_ \\ \hline Electro.pl vertical & 4029 & 0.157 & 2.048 & 0.089 & 0.174 & 0.096 \\ Electro.pl horizontal & 1858 & 0.072 & 0.944 & 0.041 & 0.080 & 0.044 \\ Agito.pl vertical & 2669 & 0.075 & 1.584 & 0.059 & 0.101 & 0.067 \\ Agito.pl horizontal & 1920 & 0.054 & 1.304 & 0.043 & 0.073 & 0.048 \\ Morele.net vertical & 1777 & 0.104 & 0.905 & 0.054 & 0.079 & 0.052 \\ Morele.net horizontal & 1953 & 0.114 & 0.752 & 0.059 & 0.087 & 0.058 \\ \hline Merlin.pl vertical & 1977 & 0.108 & 0.351 & 0.049 & 0.156 & 0.084 \\ \hline Merlin.pl horizontal & 1312 & 0.072 & 0.285 & 0.032 & 0.104 & 0.056 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Recommending interface quality parameters.