|Review Comment: |
The authors have, overall, addressed my previous comments. The introductory sections and the background justifying the work and describing the interface are much easier to follow. The limitations are also more clearly explained. I’d recommend an accept subject to addressing the following.
One claim that probably needs toning down still is wrt to learnability and usability - 2nd para on p.21 - I can see only “0 (Hard to learn/use), 1 (Easy to learn/use)” in addition to the SUS. Both are a lot more complex than that question, and typically are derived based on a set of questions addressing specifically identified potential usability issues. Of course, that may have been done here, in which case I either missed it or the information is not provided. If the former - cross-reference here, if the latter please provide it.
Similarly, on p.23 - the authors hypothesise about support for relationship finding and also why google outperformed the visualisation tools. Did you by any chance go back to ask the participants for their opinions?
Re - literature review - I asked myself a couple of times - why refer to specific tools and then dismiss them as, e.g., “… they are not directly comparable with Aemoo as they …”
An interesting point I did not pick up on earlier: Google performed better at the RELATIONSHIP task than the two visualisation-based tools with a key function being relationship identification/visualisation! Google doing better is explained away by popularity - this may be so, am not debating that here - but might be worth finding out from the participants what may have contributed to this.
********* other minor points
p.2 - don’t understand the first half of this sentence -
“If Wikipedia article writing and hyperlinking confirm this intuition for each entity type in its ontology is an empirical matter, and we have performed data mining and experiments  to this aim, proving that automatically extracted EKPs can be trusted as relevant con- figurations of data for a given entity type.”
Fig4a - caption and main text refer to Alan Turing - actual diagram is about Kant
Is the relationship “between Prussia and Baltic See (cf. 4(b))” really unexpected - I would’ve thought it was obvious.
p.15 - “(i) although Google does not provide an interface specially designed for exploratory search, it is currently the most used exploratory tool on the Web. Users have developed their own methods for exploring and discovering knowledge by using Google, and they are very familiar with its interface. ” - sufficiently strong claim, especially since used later on to bolster the argument about usability of Aemoo, that it really needs some backing evidence.
Fig. 7 - this is is for the Likert scale (1-5 ?), right? Q2 & 3 say “I am an expert user of Aemoo/RelFinder” - and
“ They declared to have … no knowledge about RelFinder and Aemoo “ - but both bars have average above 1!
* a few typos/errors