## 4 Experimental Analysis and Results
### Editing the Name Tag Attribute  
We have analysed the objects in our case-study which have \"name\" attributes. In Table 3 an example is given where five different name values are assigned to the \"name\" attribute or key. The current version of this object is version \(26\) edited on \(04\)/\(12\)/\(2010\) with the name tag assigned the value of \"Old Crosby\". In \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Contributions** & **\#Unique Contributors** & **\% Contributors** & **Total \%** \\ \hline \(\leq\)\(5\) & \(2128\) & \(51.55\) & \(51.55\) \\ \(5\)–\(10\) & \(521\) & \(12.62\) & \(64.17\) \\ \(10\)–\(20\) & \(404\) & \(9.78\) & \(73.95\) \\ \(20\)–\(50\) & \(378\) & \(9.15\) & \(83.11\) \\ \(50\)–\(100\) & \(252\) & \(6.10\) & \(89.22\) \\ \(100\)–\(200\) & \(175\) & \(4.23\) & \(93.46\) \\ \(200\)–\(500\) & \(163\) & \(3.94\) & \(97.41\) \\ \(500\)–\(1000\) & \(67\) & \(1.62\) & \(99.03\) \\ \(1000\)–\(2000\) & \(20\) & \(0.48\) & \(99.51\) \\ \(2000\)–\(5000\) & \(18\) & \(0.43\) & \(99.95\) \\ \(\geq\)\(5000\) & \(3\) & \(0.048\) & \(99.99\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The number of edits or contributions performed by all of the OSM contributors in our case-study area. Figure 2: The distribution of the number of unique contributors to each geographic object in our OSM study area. our case study \(9837\) objects have a \"name\" attribute. There are \(412\) (\(4.1\%\)) objects where the assignment to the \"name\" key changes \(3\) or more times (as shown in the example in Table 3). We calculated the correlation between the number of changes of the \"name\" attribute and the number of editors who had edited the corresponding object. However the result is inconclusive. A very weak negative correlation of \(-0.17\) was calculated which does not allow us to make any assumptions about the reasons for this behaviour. A total of \(43\) objects had their \"name\" attribute changed \(3\) or more times by the same contributor. On the other end of the scale \(112\) of the objects had their \"name\" attribute changed \(3\) or more times in the presence of \(6\) or more unique contributors. As shown by [PERSON] _et al._[35] in Wikipedia edits (particularly deletions) of content by other contributors are considered as disapproval whereas maintaining the edits of previous editors is deemed as a sign of approval. In the case of \"name\" attribute changes in the presence of multiple authors a deeper analysis is required as to why these changes occur. This may possibly involve asking contributors to fill in a questionnaire regarding their decision making processes for changing attributes such as \"name\". Whilst our study area, for this paper, is confined to the UK and Ireland we feel that it is useful to the discussion to show an example from the German OSM. We chose this example because of the unusually high number of edits to the \"highway\" tag for this feature. A \"tag war\" has broken out amongst OSM contributors over what they individually perceive as the correct hierarchy value for the highway tag. Up to mid-February \(2011\)\(88\) versions of this polyline have been created. OSM contributor ID \(7070\) seems to intend on ensuring that the highway tag _always_ has the value of trunk whereas all other contributors who have supplied edits to this polyline believe the correct tag value is construction. Viewing of aerial imagery of this feature in Google Maps and Bing Maps is inconclusive and potential erroneous given that the aerial imagery may be old and out-of-date. A segment of the history trail of edits for this object is shown in Table 4. We investigated the values assigned to tags and analysed if edits to those tags resulted in reverts or the assignment of new values. In total \(64\%\) of tag edits resulted in the values of tags being reverted to a previous value. In \(32\%\) of tag edits the value(s) assigned to a tag where updated or changed to a new value. It is difficult to comment if these reverts to old values or assignment of new values are strictly correct.