Reviewer:

1) Is the subject matter relevant?

Yes – very interesting; this article deals with IP controversies and licensing choices in 3D printing – as the authors rightly note, it’s something that will only grow in importance.

2) Is the treatment of the subject matter intellectually interesting? Are there citations of bodies of literature you think are essential to which the author has not referred?

The authors present an interesting discussion and a good analysis of the data. It is mostly well situated within the literature. My major suggestion to improve the paper is to better integrate the two substantive parts. The IP controversies in Thingiverse that are presented as case studies do not really frame the data collected and analysed – the paper seems almost at times like two halves of different papers. The link between these two halves is that Thingiverse does not seem to be as open as the rhetoric that surrounds it – either from the platform’s side or from the point of view of users, half of whom choose to keep their Things private. I think this is really interesting, but I would like to see it expanded upon. There’s not quite enough given to make a compelling argument or analysis, but there is certainly the potential to do so.

3) Are there any noticeable problems with the author’s mean of validating assumptions or making judgments?

Because much of the link discussed above rests on the speculation about why many Things are private, I think this needs to be treated in a slightly more in-depth way than it currently is. I would assume, for example, that many people are just experimenting with 3D printing, and don’t necessarily feel the confidence to share their designs with a wide audience – but I’m not sure that it necessarily follows that Thingiverse does not have an ‘open’ culture. I’d really like to see the authors tease this out a bit more.

4) Is the article well written?

Yes. My main suggestion is to make the argument a bit more clear in the introduction to better explain the conclusions to the reader.

5) Are there portions of the article that you recommend to be shortened, excised or expanded?

As above – I think the analysis and the link between the parts of the paper could usefully be expanded.

Reviewer:

1) Is the subject matter relevant?

Yes. However, the most interesting issues have only been treated superficially. For example,

2) Is the treatment of the subject matter intellectually interesting? Are there citations of bodies of literature you think are essential to which the author has not referred?

The introductory part is very interesting but the empirical part is a bit weak, and only scratches the surface without going deeper into potential causalities or explanations of the collected and described data.

3) Are there any noticeable problems with the author’s mean of validating assumptions or making judgements?

“To make things worse, MakerBot released new 3D printing software to accompany the new printer which also did not comply with open source principles.”

This implies judgment of the business strategy, which should be discussed.

4) Is the article well written?

Yes.

5) Are there portions of the article that you recommend to be shortened, excised or expanded?

A description of Thingiverse’s business model would be very helpful. The business model and the question regarding the openness of the platform are at the core of the issues discussed in this article. For example, does the site sell advertisement space or are there any fees/premium memberships? Is Thingiverse predominately a vehicle to promote Makerbots? Clarifications of these issues could help to interpret the behaviours of users and the platform better.

“Our first finding, based on an analysis of metadata from the 68,618 Public Things in our sample”.

Here, the authors speak of a “sample”. Before, they indicate that the 117,450 Things are the entirety of Things available on Thingiverse between the indicated time frame? If it is a sample, the authors should discuss the sampling technique.

As the license choice is at the core for the article’s arguments, an elaboration on the process how users chose a license would be insightful. Eg does the site recommend specific licenses? Does the site offer explanations about licenses? Do uploaders have to actively choose a license or is a default license applied?

Regarding figure 2: It could be made clearer that the text refers to the size of the blobs. Also, a quick explanation about the difference between “amount of remixes” and “amount of makes” would be helpful. Especially, as the figure indicates that there is a significant difference between the BY and BY-SA Things with regards to “amount of makes” but the text does not address this difference.

“In other words, non-sticking licences seem to be preferred when remixing objects“.

This conclusion should be discussed a bit more in-depth. Isn’t it trivial that remixers prefer less restrictive licenses provided that all other factors are constant (which has to be assumed if no other information is given)? Why should someone choose a Thing with a more restrictive license if the same Thing is available with a less restrictive license? There might be other factors potentially influencing the decision to remix a Thing such as perceived quality.

“This remixing pattern can be compared with how users use the “collection” function. CC BY (blue) and CC BY-SA (grey) licensed Things are almost equal in terms of how many times they are included in user collections.” […] “Licence choice does not seem to make a difference in collections”.

What is the assumed motivation of users to include Things in collections? Respectively, what is the implication of this observation? Some informed speculations of the authors about the reasons and implications of those findings would be insightful.

“The most common tag that users attach to Things is customized (19,206 times). This tag, which refers to Thingiverse users handling Things in a way more close to ‘remixing’ these designs than ‘building them from scratch’, reveals the iterative, collaborative kind of production model on which that Thingiverse prides itself.”

The numbers should be put into perspective. Of 117,450 Things in total (assuming it is the total population and not a sample, see comment above) 68,618 are public of which 19,206 are customized (16% of total). This is not a majority. Hence, the number does not support strongly the claim that Thingiverse is a collaborative platform. To put it a different way, according to the data, 84% of Things are either private or not customized. Some discussion of this point would be good.

Things with “private” status have been saved as drafts. Interestingly, it seems that over time the share of Private Things among all Things has been growing.

The data only provides weak support for this conclusion because the time frame is short (3 month) and the increase is minor (< 2%). It might be just a random fluctuation.

“If it is true that closed systems tend toward control, while open ones tend toward innovation, then the enclosure of Thingiverse may suggest that it is losing its innovative character.”

It’s not really clear whether the “system” refers to the openness of Thingiverse.com or the openness of its users. Above, the authors describe Thingiverse as a “commercial, proprietary platform, owned by a large, global corporation”. I do not understand why there has to be an alignment between the platform’s philosophy regarding openness and the users’ philosophies. In other words, a platform can be closed but provide services for users to share content openly, depending on the business model.

A few words about a possible link between the quality of Things and chosen licenses would be interesting. Intuitively, I would expect that high quality Things are published under more restrictive licenses (as more time and effort have been invested) than low quality Things.