Indirect patent citations

Patent citations are extensively used as a measure of patent quality. However, counting citations does not account for the fact that citations come from patents of different qualities, and that citations are of variable qualities. We develop a citation index which takes into account the cumulative quality of the citing patents. We apply this index to the 2,139,314 utility patents granted in the U.S. between 1975 and 1999. We study the properties of this index by year and by technological category, and analyse the links between patents.     

Analyzing the value of technology based on the differences of patent citations between applicants and examiners

Patent applicants and examiners do not always have the same point of view when conducting a prior-art search. Although several studies have suggested differences between citations by applicants and examiners, the data and range of empirical studies are too incomplete to generalize the characteristics of relationships between citation types and the value of a technology or invention. To overcome this limitation, it is crucial to compare citations by applicants and by examiners in depth, with diverse perspectives and data, to determine the value of patent information for technological innovation. Thus, this paper suggests that the differences in the composition of technical information and patent quality in patent-level investigations as well as the locus of the knowledge source and knowledge recentness in knowledge-level investigations according to patent citation type (by applicants and examiners) reflect Pavitt’s perspective on the nature, impact, and source of technological innovation. We found that the quality of patents cited by applicants is higher than that of those by examiners in four industries, excluding a supplier-dominated industry. The citation types are related to the locus of the knowledge source in four industries, excluding the supplier-dominated industry. In particular, the patents cited by examiners tended to be more recently issued in all sectoral fields. This research contributes to confirming the technological value of patents based on the citation behaviors of applicants and examiners through empirical analysis. The results can be utilized to investigate signals or noise in technological innovation and improve processes or systems of patent examination. In addition, it can help applicants conduct more thorough prior-art searches by comprehending the examiner’s perspective toward citations to increase the probability of patent registration.     

Triadic citations,country biases and patent value: the case of pharmaceuticals

Triadic patents minimise home bias effects in studies that focus on patent counts as a measure of innovative activity. Yet, biases in qualitative patent indicators have been largely neglected. This article advocates that forward patent citations, and triadic citations in particular, can illuminate further on home bias, self citations, and the speed of knowledge flows for drug patents published by the USPTO for the period 1980–2008. The evidence shows that triadic citations help to minimize the home bias in citations as well as to make patent quality more transparent. Also, it indicates that self citations and the age distribution of citations are important factors to consider when explaining cross-country differences in pharmaceutical citations.     

The money value of citations to single-authored and multiple-authored articles

This note presents evidence for the surprising conclusion that a citation to a multiple-authored article is worth more to its author than a citation to a single-authored article.     

Factors to evaluate a patent in addition to citations

The emergence of patent citations as a tool for patent estimation has been subjected to equally vocal champions and critics. In additional to patent citation, this article aims to contribute other factors, including court decisions, claim language, extension cases, patent family and portfolio, which should be deliberated during patent evaluation. It introduces the subject-matter by discussing the specialties and peculiarities of these proposed factors. Furthermore, comparisons between the patent citations and these factors are presented by illustrating several well-known patents. The results of the comparisons reveal that an adverse conclusion might be drawn if a patent is estimated only based on citations. The conclusion supports Meyer’s study that “the general nature of a common framework for both scientific and patent citations would severely limit its usefulness.” Therefore, those factors discussed in the article would be a great asset in patent evaluation. However, it only illustrates their impact on patent estimation using a couple well-known patents. Future research would be needed to investigate these factors in a more detailed manner.     

Towards understanding the relation between citations and research quality in software engineering studies

The importance of achieving high quality in research practice has been highlighted in different disciplines. At the same time, citations are utilized to measure the impact of academic researchers and institutions. One open question is whether the quality in the reporting of research is related to scientific impact, which would be desired. In this exploratory study we aim to: (1) Investigate how consistently a scoring rubric for rigor and relevance has been used to assess research quality of software engineering studies; (2) Explore the relationship between rigor, relevance and citation count. Through backward snowball sampling we identified 718 primary studies assessed through the scoring rubric. We utilized cluster analysis and conditional inference tree to explore the relationship between quality in the reporting of research (represented by rigor and relevance) and scientiometrics (represented by normalized citations). The results show that only rigor is related to studies’ normalized citations. Besides that, confounding factors are likely to influence the number of citations. The results also suggest that the scoring rubric is not applied the same way by all studies, and one of the likely reasons is because it was found to be too abstract and in need to be further refined. Our findings could be used as a basis to further understand the relation between the quality in the reporting of research and scientific impact, and foster new discussions on how to fairly acknowledge studies for performing well with respect to the emphasized research quality. Furthermore, we highlighted the need to further improve the scoring rubric.     

Diversity of fields in patent citations: synchronic and diachronic changes

While there is a large body of research analyzing the overall structure of citation relations for patents, there has been very little research seeking to clarify the characteristics of fields relating to the diffusion of technology through observing the citation network surrounding each patent individually and tracing its growth. This study focused on the classifications assigned to patents and examined the diversity of the fields of patents citing each patent from the following two perspectives: (1) expected values for growth in the number of citing fields, when regarding the observation period as being in a synchronic state and assuming that the strength of connections between each patent and citing fields is constant; and (2) empirical values for growth in the number of citing fields according to the increase in the cumulative number of citations over time. From the results, it was confirmed that the strength of potential connections between each patent and citing fields changes over time. Especially in the fields of “chemistry; metallurgy” and “physics,” the following change is considerable: a patent tends to receive citations repeatedly from a limited range of fields for a while, but later comes to be cited by various fields.     

The choice of examiner patent citations for refusals: evidence from the trilateral offices

Utilizing a novel methodology based on international family-to-family patent citation data, this paper directly compares X/Y patent citations (i.e., those cited as grounds for rejections, equivalent to “blocking patents” in the US) between major patent offices. Remarkable discrepancies between the offices were revealed, despite the common patentability criteria of novelty and inventive step to generate citations. This paper then introduces a simple cosine similarity measurement between a family of X/Y patent citations and all citations added globally to the same original application. How the discrepancies of X/Y patent citations at the European Patent Office (EPO) and the US Patent and Trademark Office (USPTO) relate to the characteristics of applications and longitudinal aspects of office actions were also examined. X/Y patent citations from both the EPO and USPTO commonly show that the range of patent application classes is positively correlated with divergent reasons for refusal, suggesting that costly examinations lead to diversified X/Y patent citations. One novel methodological feature of this paper is that examiner citations across jurisdictions are comparable if we employ family-to-family citations and common criteria for the X/Y citation category. Furthermore, unlike the normal citation-generating process where a citing document adds citations to prior art only once, this paper represents the first attempt to analyze a citation network with multiple citing opportunities from separate parties. We find that the variance of citation linkages has a negative relationship with the ease in which different citers evaluate prior art in the same way, thereby providing a new perspective on the notion of breadth in citation impact.     

The correlation between paper length and citations: a meta-analysis

Scientometrics - Citation count is a widely used bibliometric indicator. It is influenced by many factors, some of which have been well investigated. This study investigated a more controversial...     

The relationship between usage and citations in an open access mega-journal

Scientometrics - How do the level of usage of an article, the timeframe of its usage and its subject area relate to the number of citations it accrues? This paper aims to answer this question...     

Exploring the quality of environmental technology in Europe: evidence from patent citations

In this paper we carry out an empirical analysis to address some questions concerning the production and quality of technology in environmental sectors. The methodology involves patents as a measure of the generation of new knowledge, and patent citations as a proxy for the quality of a technological invention. The sample contains more than 12,000 environmental European patents from firms and government institutions from 1998 to 2004. From our econometric analysis, we found that environmental patents applied by individual inventors present on average less quality that those applied by institutional inventors. The size of family patent is relevant to explain forward patent citation. Furthermore, patents coming from abroad (out of Europe), in particular with US and Japan priority, are more cited on average than local patents (with European priority). Lastly, the specialization in environmental fields of a patent plays a negative role in determining the frequency of forward citation.     

The growing number of patent citations to scientific papers: Changes in the world,nations, and fields

This study analyzes USPTO patents in the period 1998–2017. The number of science-related patents has increased twice as fast as the number of patents and scientific publications, and the number of cited papers per patent has almost doubled. These results vary substantially from one scientific and technological field to another. The proportion of the research papers cited by a patent has doubled. It refers to papers that are mostly published by the countries that have developed both scientific and technological capability and, surprisingly, are mainly used by inventors abroad. However, a weak relationship between the number of citations received from patents and papers reveals that the assessment of research performance needs some changes as the percentage of papers related to the innovations has grown over time.     

The bibliographic coupling approach to filter the cited and uncited patent citations: a case of electric vehicle technology

Because some cited references are not relevant to the citing patent and not all the relevant references are cited, the study attempts to use the bibliographic coupling (BC) approach to filter the irrelevant patent citations and supplement the relevant uncited patent citations to construct a patent citation network (PCN). The study selected the field of electric vehicle technology to explore the phenomenon and examined the characteristics of PCNs in terms of the average BC strength and the average citation time lag. Four PCNs were constructed in this study. The aggregated PCN (APCN) excluded the irrelevant patent citations and added the relevant uncited patent citations, which has brought out significant improvement. The APCN became more concentrated and the information which reserved in the APCN was the most current. Additionally, some invisible technology clusters and relationships were also manifested in the APCN.     

What do patent examiner inserted citations indicate for a region with low absorptive capacity?

Most studies of patents citations focus on national or international contexts, especially contexts of high absorptive capacity, and employ examiner citations. We argue that results can vary if we take the region as the context of analysis, especially if it is a region with low absorptive capacity, and if we study applicant citations and examiner-inserted citations separately. Using a sample from the Valencian Community (Spain), we conclude that (i) the use of examiner-inserted citations as a proxy for applicant citations, (ii) the interpretation of non-patent references as indicators of science-industry links, and (iii) the traditional results for geographical localization are not generalizable to all regions with low absorptive capacity.     

Exploring the patterns of international technology diffusion in AI from the perspective of patent citations

Scientometrics - This paper presents the findings from a thorough analysis of international technology diffusion (ITD) in artificial intelligence (AI) technologies. We construct a novel framework...     

The role of patent information in relation to transfer of technology

After some general remarks about various aspects of transfer of technology to developing countries, the potential contributions thereto of patent documentation are enumerated. A recent survey shows that so far in Brazil only very little of this potential has been realized. Various ways in which the Brazilian INPI is promoting the use of patent information are indicated.     

Reassessing the N-rays reference network: The role of self citations and negative citations

In his article networks of Scientific Papers,Price argued that the N-rays reference network exhibits characteristics one would expect for a cumulative and rapidly developing research area. Although subsequent researchers have questioned Price's characterization of the N-rays network, there have been no replications of Price's work for either the N-rays literature or for any other literature. We reexamine the N-rays reference network, this time distinguishing negative citations and self citations from other citations. Although previous studies of negative and self citations show they are relatively infrequent in scientific literatures, we find that both are very prominent in the N-rays literature. In addition, we show that self citations comprise most of the recency effect observed in the N-rays reference network, and that the high level of self citations in the N-rays literature results primarily from the character of the journal that published the majority of the N-rays papers. Our findings therefore support those who have been skeptical about Price's claim that the N-rays reference graph exemplifies basic characteristics of the structure of scientific literatures.