Characterizing human random-sequence generation in competitive and non-competitive environments using Lempel–Ziv complexity

The human ability for random-sequence generation (RSG) is limited but improves in a competitive game environment with feedback. However, it remains unclear how random people can be during games and whether RSG during games can improve when explicitly informing people that they must be as random as possible to win the game. Nor is it known whether any such improvement in RSG transfers outside the game environment. To investigate this, we designed a pre/post intervention paradigm around a Rock-Paper-Scissors game followed by a questionnaire. During the game, we manipulated participants’ level of awareness of the computer’s strategy; they were either (a) not informed of the computer’s algorithm or (b) explicitly informed that the computer used patterns in their choice history against them, so they must be maximally random to win. Using a compressibility metric of randomness, our results demonstrate that human RSG can reach levels statistically indistinguishable from computer pseudo-random generators in a competitive-game setting. However, our results also suggest that human RSG cannot be further improved by explicitly informing participants that they need to be random to win. In addition, the higher RSG in the game setting does not transfer outside the game environment. Furthermore, we found that the underrepresentation of long repetitions of the same entry in the series explains up to 29% of the variability in human RSG, and we discuss what might make up the variance left unexplained.

Characterizing human random-sequence generation in competitive and non-competitive environments using Lempel-Ziv complexity

The human ability for random-sequence generation (RSG) is limited but improves in a competitive game environment with feedback. However, it remains unclear how random people can be during games and whether RSG during games can improve when explicitly informing people that they must be as random as possible to win the game. Nor is it known whether any such improvement in RSG transfers outside the game environment. To investigate this, we designed a pre/post intervention paradigm around a Rock-Paper-Scissors game followed by a questionnaire. During the game, we manipulated participants’ level of awareness of the computer’s strategy; they were either (a) not informed of the computer’s algorithm or (b) explicitly informed that the computer used patterns in their choice history against them, so they must be maximally random to win. Using a compressibility metric of randomness, our results demonstrate that human RSG can reach levels statistically indistinguishable from computer pseudo- random generators in a competitive-game setting. However, our results also suggest that human RSG cannot be further improved by explicitly informing participants that they need to be random to win. In addition, the higher RSG in the game setting does not transfer outside the game environment. Furthermore, we found that the underrepresentation of long repetitions of the same entry in the series explains up to 29% of the variability in human RSG, and we discuss what might make up the variance left unexplained.

Determinants of societal and academic recognition: Evidence from randomised controlled trials

Given the increasing importance of recognition in academia and the vital role of randomised controlled trials (RCTs) in medical research and clinical decisions, this study verifies how RCTs’ academic and societal impacts are affected by visibility factors, subjects and methodological validity. This study concentrated on a sample of 446 RCTs indexed in Scopus and evaluated by Cochrane reviewers in terms of their methodological validity. The altmetrics, bibliometric and bibliographical information were extracted from Altmetric.com and Scopus, and the contributing countries’ development ranks were obtained from the United Nations Development report. The linear regression analyses revealed that citations and altmetrics depend on some subjects. They are also affected by publication year and journals’ previous reputation. Citations are also affected by keyword counts and reference counts. Keyword counts and contributing countries’ developmental rank also predict the tweet counts. While none of the methodological validity dimensions were found to predict citations, ‘Incomplete Outcome Data’ and ‘Random Sequence Generation’ significantly, though slightly, affect Mendeley Readership and tweets, respectively. By confirming the dependence of RCTs’ recognition on some methodological validity features and attention-inducing characteristics, the study provides further evidence on the interaction of quality and visibility dynamisms in the recognition network and the complementary role of societal mentions for academic citation.

The methodological quality of 176,620 randomized controlled trials published between 1966 and 2018 reveals a positive trend but also an urgent need for improvement

Many randomized controlled trials (RCTs) are biased and difficult to reproduce due to methodological flaws and poor reporting. There is increasing attention for responsible research practices and implementation of reporting guidelines, but whether these efforts have improved the methodological quality of RCTs (e.g., lower risk of bias) is unknown. We, therefore, mapped risk-of-bias trends over time in RCT publications in relation to journal and author characteristics. Meta-information of 176,620 RCTs published between 1966 and 2018 was extracted. The risk-of-bias probability (random sequence generation, allocation concealment, blinding of patients/personnel, and blinding of outcome assessment) was assessed using a risk-of-bias machine learning tool. This tool was simultaneously validated using 63,327 human risk-of-bias assessments obtained from 17,394 RCTs evaluated in the Cochrane Database of Systematic Reviews (CDSR). Moreover, RCT registration and CONSORT Statement reporting were assessed using automated searches. Publication characteristics included the number of authors, journal impact factor (JIF), and medical discipline. The annual number of published RCTs substantially increased over 4 decades, accompanied by increases in authors (5.2 to 7.8) and institutions (2.9 to 4.8). The risk of bias remained present in most RCTs but decreased over time for allocation concealment (63% to 51%), random sequence generation (57% to 36%), and blinding of outcome assessment (58% to 52%). Trial registration (37% to 47%) and the use of the CONSORT Statement (1% to 20%) also rapidly increased. In journals with a higher impact factor (>10), the risk of bias was consistently lower with higher levels of RCT registration and the use of the CONSORT Statement. Automated risk-of-bias predictions had accuracies above 70% for allocation concealment (70.7%), random sequence generation (72.1%), and blinding of patients/personnel (79.8%), but not for blinding of outcome assessment (62.7%). In conclusion, the likelihood of bias in RCTs has generally decreased over the last decades. This optimistic trend may be driven by increased knowledge augmented by mandatory trial registration and more stringent reporting guidelines and journal requirements. Nevertheless, relatively high probabilities of bias remain, particularly in journals with lower impact factors. This emphasizes that further improvement of RCT registration, conduct, and reporting is still urgently needed.

The effectiveness of the loci method as a mnemonic device: Meta-analysis

The “loci method” is a popular mnemonic device that involves visualising and recalling items at specific points along a familiar route. The loci method has been used for thousands of years, and by many successful memory athletes; yet there have been relatively few educational and clinical applications, possibly owing to empirical uncertainty. The current meta-analysis of 13 randomised controlled trials (RCTs) mostly based in university settings demonstrated the effectiveness of the loci method as a mnemonic device, with a medium effect size ( g = 0.65, 95% confidence interval [CI] = [0.45, 0.85]; I2 = 45.5%). The effect size remained at similar levels in further analyses adjusting for publication bias, the impact of removing each study, setting, control conditions, outliers, and number of loci method sessions. High risk of experimental bias was indicated, however, as the vast majority of studies did not report procedures to minimise biases relating to random sequence generation and allocation concealment. Overall, this meta-analysis of predominantly university-based RCTs has provided good initial support for the loci method as a mnemonic device and this may encourage future investigations and applications, particularly in educational settings, where it has the potential to improve recall of information relevant to academic success.

Can Humans Become More Random?

The human ability for random-sequence generation (RSG) is limited but improves in a competitive game environment with feedback. However, it remains unclear whether RSG during games can improve when explicitly informing people that they must be as random as possible to win the game nor is it known whether any such improvement transfers to outside the game environment. To investigate this, we designed a pre/post intervention paradigm around a rock-paper-scissors game followed by a questionnaire. During the game we manipulated participants’ level of awareness of the computer’s strategy; they were either (a) not informed of the computer’s algorithm or (b) explicitly informed that the computer used patterns in their choice history to beat them, so they must be maximally random to win. Using a novel comparison metric, our results demonstrate that human RSG can reach levels statistically indistinguishable from computer pseudo-random generators in a competitive-game setting. However, our results also suggest that human RSG cannot be further improved by explicitly informing participants that they need to be random to win. In addition, the higher RSG in the game setting does not transfer outside the game environment. Furthermore, we found that the underrepresentation of long repetitions of short patterns explains about a third of the variability in human RSG and discuss what might make up the remaining two thirds of RSG variability. Finally, we discuss our results in the context of the “Network-Modulation Model” and we ponder their potential relation to findings in the neuroscience of volition.

Development of a Pseudo-Random Sequence Generation Function Based on the “Kuznechik” Cryptographic Algorithm

Purpose: increasing the cryptographic strength level of the pseudo-random sequence generation function based on the «Kuznechik» encryption algorithm. Research methods: methods for constructing pseudo-random sequence generators using a strong cryptographic algorithm as a generation function in accordance with the recommendations of NIST SP 800-90. Methods of probability theory and mathematical statistics (statistical hypothesis testing, Pearson’s criterion), methods for estimating the entropy of a random process. Results: а method for development of the main component of the deterministic generator – the function for generating pseudo-random sequences based on the «Kuznechik» encryption algorithm (Russian encryption standard GOST R 34.12-2015) due to a number of the original algorithm modifications is proposed. Features of the algorithm allow to use it in a mode that combines the advantages of the well-known encryption modes of block ciphers (OFB and CTR encryption modes). A procedure for generating round keys and other modifications of the algorithm that increase its security while maintaining its performance have been developed and implemented. The generator operation was evaluated on the basis of the statistical properties of the output sequences (NIST SP 800-22 tests), Pearson’s χ2 criterion, and min-entropy (NIST 800-90B tests). According to the characteristics mentioned above, the proposed generation function is comparable with the reference version based on GOST 34.12-2015 «Kuznechik», but exceeds it in terms of security.