Quantifying the impact of weak, strong, and super ties in scientific careers

Scientists are frequently faced with the important decision to start or terminate a creative partnership. This process can be influenced by strategic motivations, as early career researchers are pursuers, whereas senior researchers are typically attractors, of new collaborative opportunities. Focusing on the longitudinal aspects of scientific collaboration, we analyzed 473 collaboration profiles using an ego-centric perspective which accounts for researcher-specific characteristics and provides insight into a range of topics, from career achievement and sustainability to team dynamics and efficiency. From more than 166,000 collaboration records, we quantify the frequency distributions of collaboration duration and tie-strength, showing that collaboration networks are dominated by weak ties characterized by high turnover rates. We use analytic extreme-value thresholds to identify a new class of indispensable `super ties', the strongest of which commonly exhibit >50% publication overlap with the central scientist. The prevalence of super ties suggests that they arise from career strategies based upon cost, risk, and reward sharing and complementary skill matching. We then use a combination of descriptive and panel regression methods to compare the subset of publications coauthored with a super tie to the subset without one, controlling for pertinent features such as career age, prestige, team size, and prior group experience. We find that super ties contribute to above-average productivity and a 17% citation increase per publication, thus identifying these partnerships - the analog of life partners - as a major factor in science career development.Comment: 13 pages, 5 figures, 1 Tabl

The Z-index: A geometric representation of productivity and impact which accounts for information in the entire rank-citation profile

We present a simple generalization of Hirsch's h-index, Z = \sqrt{h^{2}+C}/\sqrt{5}, where C is the total number of citations. Z is aimed at correcting the potentially excessive penalty made by h on a scientist's highly cited papers, because for the majority of scientists analyzed, we find the excess citation fraction (C-h^{2})/C to be distributed closely around the value 0.75, meaning that 75 percent of the author's impact is neglected. Additionally, Z is less sensitive to local changes in a scientist's citation profile, namely perturbations which increase h while only marginally affecting C. Using real career data for 476 physicists careers and 488 biologist careers, we analyze both the distribution of $Z$ and the rank stability of Z with respect to the Hirsch index h and the Egghe index g. We analyze careers distributed across a wide range of total impact, including top-cited physicists and biologists for benchmark comparison. In practice, the Z-index requires the same information needed to calculate h and could be effortlessly incorporated within career profile databases, such as Google Scholar and ResearcherID. Because Z incorporates information from the entire publication profile while being more robust than h and g to local perturbations, we argue that Z is better suited for ranking comparisons in academic decision-making scenarios comprising a large number of scientists.Comment: 9 pages, 5 figure

The Self-Organization of Meaning and the Reflexive Communication of Information

Following a suggestion of Warren Weaver, we extend the Shannon model of communication piecemeal into a complex systems model in which communication is differentiated both vertically and horizontally. This model enables us to bridge the divide between Niklas Luhmann's theory of the self-organization of meaning in communications and empirical research using information theory. First, we distinguish between communication relations and correlations among patterns of relations. The correlations span a vector space in which relations are positioned and can be provided with meaning. Second, positions provide reflexive perspectives. Whereas the different meanings are integrated locally, each instantiation opens global perspectives--"horizons of meaning"--along eigenvectors of the communication matrix. These next-order codifications of meaning can be expected to generate redundancies when interacting in instantiations. Increases in redundancy indicate new options and can be measured as local reduction of prevailing uncertainty (in bits). The systemic generation of new options can be considered as a hallmark of the knowledge-based economy.Comment: accepted for publication in Social Science Information, March 21, 201

A quantitative perspective on ethics in large team science

The gradual crowding out of singleton and small team science by large team endeavors is challenging key features of research culture. It is therefore important for the future of scientific practice to reflect upon the individual scientist's ethical responsibilities within teams. To facilitate this reflection we show labor force trends in the US revealing a skewed growth in academic ranks and increased levels of competition for promotion within the system; we analyze teaming trends across disciplines and national borders demonstrating why it is becoming difficult to distribute credit and to avoid conflicts of interest; and we use more than a century of Nobel prize data to show how science is outgrowing its old institutions of singleton awards. Of particular concern within the large team environment is the weakening of the mentor-mentee relation, which undermines the cultivation of virtue ethics across scientific generations. These trends and emerging organizational complexities call for a universal set of behavioral norms that transcend team heterogeneity and hierarchy. To this end, our expository analysis provides a survey of ethical issues in team settings to inform science ethics education and science policy.Comment: 13 pages, 5 figures, 1 table. Keywords: team ethics; team management; team evaluation; science of scienc

"Dey were gotten escapit": A sociolinguistic study on pre-oil Shetland dialect

Denne oppgaven er en sosiolingvistisk studie om språklig endring på Shetland basert på intervjuer med Shetlendere født mellom 1877 og 1932. Intervjuene er hentet fra et nettarkiv med opptak fra nittenfemti, seksti og syttitallet. De ble gjennomført av både lokale forskere, og et flertall av forskere fra resten av Storbritannia. Jeg har delt informantene inn i tre aldersgrupper og to kjønnskategorier. Tidligere studier på Shetlandsdialekten har undersøkt talemålet til informanter som har vokst opp rett før, under, og etter oppdagelsen av olje utenfor Shetland i 1970. Disse har også undersøkt både variabler som opptrer i hele Skottland, og variabler som er spesifikke for Shetland. Jeg har valgt å fokusere på to variabler som er spesifikke for Shetland, nemlig TH-stopping og be-perfektum. Ut ifra tidligere forskning hadde jeg en forventing om at forekomsten av lokale varianter ville synke gradvis mellom de tre aldersgruppene. Mine data viser at det er en kjønnsforskjell i hvilke språklige endringsmønstre man ser i de ulike generasjonene. Hos mine mannlige informanter er det de eldste og de yngste talerne som bruker flest lokale trekk. Den mellomste mannlige gruppen bruker en overvekt av standardiserte trekk fra Standard Scottish English (SSE). Blant kvinnene fant jeg en mer gradvis dreining mot standardiserte trekk. For variabelen TH var den lokale varianten dominerende i de to eldste aldersgruppene, men den sank dramatisk hos den yngste aldersgruppen. Be-perfektum var minoritetsvariant i alle de tre aldersgruppene. I tillegg til alder og kjønn har den språklige bakgrunnen til intervjuerne vist seg å være en avgjørende faktor for informantenes talemønster. Det betyr at talernes evne til å tilpasse seg intervjuerne er en ny ukjent variabel i datasettet. Endringene vi ser i begge kjønnskategorier kan være et resultat av samfunnsmessige omveltninger som følge av verdenskrigene. Forskjellen mellom kjønnene stemmer også overens med tidligere sosiolingvistisk forskning på kjønn og språkendringer.Engelsk mastergradsoppgaveENG350MAHF-ENGMAHF-LÆF

Scale invariant properties of public debt growth

Public debt is one of the important economic variables that quantitatively describes a nation's economy. Because bankruptcy is a risk faced even by institutions as large as governments (e.g. Iceland), national debt should be strictly controlled with respect to national wealth. Also, the problem of eliminating extreme poverty in the world is closely connected to the study of extremely poor debtor nations. We analyze the time evolution of national public debt and find "convergence": initially less-indebted countries increase their debt more quickly than initially more-indebted countries. We also analyze the public debt-to-GDP ratio R, a proxy for default risk, and approximate the probability density function P(R) with a Gamma distribution, which can be used to establish thresholds for sustainable debt. We also observe "convergence" in R: countries with initially small R increase their R more quickly than countries with initially large R. The scaling relationships for debt and R have practical applications, e.g. the Maastricht Treaty requires members of the European Monetary Union to maintain R < 0.6.Comment: 9 pages, 8 figure

Commentary: The case for caution in predicting scientists’ future impact

We stress-test the career predictability model proposed by Acuna et al. [Nature 489, 201-202 2012] by applying their model to a longitudinal career data set of 100 Assistant professors in physics, two from each of the top 50 physics departments in the US. The Acuna model claims to predict h(t+\Delta t), a scientist's h-index \Delta t years into the future, using a linear combination of 5 cumulative career measures taken at career age t. Here we investigate how the "predictability" depends on the aggregation of career data across multiple age cohorts. We confirm that the Acuna model does a respectable job of predicting h(t+\Delta t) up to roughly 6 years into the future when aggregating all age cohorts together. However, when calculated using subsets of specific age cohorts (e.g. using data for only t=3), we find that the model's predictive power significantly decreases, especially when applied to early career years. For young careers, the model does a much worse job of predicting future impact, and hence, exposes a serious limitation. The limitation is particularly concerning as early career decisions make up a significant portion, if not the majority, of cases where quantitative approaches are likely to be applied.Comment: 2 pages, 1 figur