# BiTTM: A Core Biterms-Based Topic Model for Targeted Analysis
## 4 Experimental Results
### Quantitative Evaluation
In addition, comparing the two BTM variations, BTM-PD is better than BTM* in most cases, which proves that the pre-filtering strategy is more effective in removing irrelevant words than the post-filtering strategy. Secondly, the average \(P@n\) of BiTTM achieves a gain of more than 10% compared with TTM, and more than 26% compared with BTM-PD, over all queries in the table and the settings of \(n\). Moreover, the performance difference among the three types of document is not significant, whereas the different target queries have influence on the \(P@n\) results, which will be explained later using concrete examples. Thirdly, TTM is the second best model for \(P@5\). However, for \(P@10\), TTM achieves the best performance than all other models for some queries. It suggests the tendency of TTM to put target-related words in lower-ranked positions. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Type**} & \multirow{2}{*}{**Datasets**} & \multirow{2}{*}{**Targets**} & \multicolumn{3}{c}{**BiTTM**} & \multicolumn{3}{c}{**TTM**} & \multicolumn{3}{c}{**BTM-PD**} & \multicolumn{3}{c}{**BTM\({}^{*}\)**} \\ \cline{3-14}  & & & **P@5** & **P@10** & **P@20** & **P@5** & **P@10** & **P@20** & **P@5** & **P@10** & **P@20** & **P@5** & **P@10** & **P@20** \\ \hline \multirow{4}{*}{short} & cigar & ashtray & **0.92** & **0.84** & **0.6** & **0.92** & 0.66 & 0.46 & 0.6 & 0.6 & 0.39 & 0.2 & 0.2 & 0.135 \\ \cline{2-14}  & & place & **0.64** & **0.56** & **0.43** & 0.52 & 0.44 & 0.29 & 0.48 & 0.4 & 0.26 & 0.22 & 0.17 & 0.135 \\ \cline{2-14}  & \multirow{2}{*}{ecig} & smokeless & **0.72** & **0.64** & **0.45** & 0.56 & 0.5 & **0.45** & 0.44 & 0.4 & 0.31 & 0.3 & 0.24 & 0.19 \\ \cline{2-14}  & & warning & **0.6** & **0.54** & **0.54** & 0.48 & 0.46 & 0.37 & 0.36 & 0.3 & 0.25 & 0.4 & 0.24 & 0.215 \\ \cline{2-14}  & \multirow{2}{*}{Oscars} & mistake & **0.6** & **0.56** & **0.49** & 0.4 & 0.48 & 0.45 & 0.2 & 0.32 & 0.28 & 0.28 & 0.18 & 0.14 \\ \cline{2-14}  & & oscarsfail & **0.64** & **0.52** & **0.44** & 0.36 & 0.4 & 0.31 & 0.24 & 0.18 & 0.15 & 0.26 & 0.18 & 0.125 \\ \hline \multirow{4}{*}{medium} & baby & rinses & **0.52** & **0.38** & **0.3** & 0.2 & 0.26 & 0.24 & 0.08 & 0.1 & 0.11 & 0.12 & 0.12 & 0.085 \\ \cline{2-14}  & & shower & **0.52** & **0.48** & **0.38** & 0.44 & 0.4 & 0.32 & 0.2 & 0.36 & 0.31 & 0.24 & 0.19 & 0.145 \\ \cline{2-14}  & \multirow{2}{*}{camera} & portable & **0.52** & **0.48** & **0.4** & 0.4 & 0.44 & 0.29 & 0.32 & 0.28 & 0.23 & 0.1 & 0.09 & 0.08 \\ \cline{2-14}  & & price & **0.52** & **0.48** & **0.51** & 0.48 & 0.44 & 0.42 & 0.44 & 0.34 & 0.26 & 0.08 & 0.11 & 0.09 \\ \cline{2-14}  & \multirow{2}{*}{computer} & display & **0.48** & **0.74** & **0.72** & 0.4 & 0.62 & 0.62 & 0.28 & 0.32 & 0.32 & 0.1 & 0.15 & 0.165 \\ \cline{2-14}  & & keyboard & **0.52** & **0.66** & **0.59** & 0.44 & 0.6 & 0.52 & 0.32 & 0.34 & 0.33 & 0.18 & 0.15 & 0.14 \\ \hline \multirow{4}{*}{long} & \multirow{2}{*}{home} & clean & **0.76** & **0.8** & **0.69** & 0.68 & 0.72 & 0.64 & 0.32 & 0.34 & 0.32 & 0.25 & 0.19 & 0.18 \\ \cline{2-14}  & & kitchen & **0.72** & 0.72 & **0.66** & 0.68 & **0.8** & **0.66** & 0.64 & 0.52 & 0.44 & 0.22 & 0.18 & 0.16 \\ \cline{2-14}  & \multirow{2}{*}{food} & disease & **0.6** & **0.6** & **0.6** & 0.48 & 0.46 & 0.42 & 0.44 & 0.4 & 0.38 & 0.22 & 0.23 & 0.19 \\ \cline{2-14}  & & microwave & **0.84** & 0.58 & **0.47** & 0.68 & **0.64** & 0.44 & 0.32 & 0.32 & 0.26 & 0.18 & 0.17 & 0.125 \\ \cline{2-14}  & \multirow{2}{*}{care} & diabetic & **0.56** & **0.62** & **0.53** & 0.48 & 0.44 & 0.25 & 0.28 & 0.28 & 0.23 & 0.12 & 0.13 & 0.12 \\ \cline{2-14}  & & infant & **0.48** & **0.54** & **0.51** & 0.36 & 0.3 & 0.29 & 0.2 & 0.14 & 0.11 & 0.18 & 0.15 & 0.105 \\ \hline \multicolumn{2}{c}{**average score**} & **0.62** & **0.60** & **0.52** & 0.50 & 0.50 & 0.41 & 0.34 & 0.33 & 0.27 & 0.20 & 0.17 & 0.14 \\ \hline \multicolumn{2}{c}{**improvement by BiTTM**} & & & +0.12 & +0.09 & +0.10 & +0.28 & +0.27 & +0.24 & +0.42 & +0.43 & +0.38 \\ \hline \hline \end{tabular}
\end{table}