Researching interactions between humans and machines: methodological challenges

Communication scholars are increasingly concerned with interactions between humans and communicative agents. These agents, however, are considerably different from digital or social media: They are designed and perceived as life-like communication partners (i.e., as “communicative subjects”), which in turn poses distinct challenges for their empirical study. Hence, in this paper, we document, discuss, and evaluate potentials and pitfalls that typically arise for communication scholars when investigating simulated or non-simulated interactions between humans and chatbots, voice assistants, or social robots. In this paper, we focus on experiments (including pre-recorded stimuli, vignettes and the “Wizard of Oz”-technique) and field studies. Overall, this paper aims to provide guidance and support for communication scholars who want to empirically study human-machine communication. To this end, we not only compile potential challenges, but also recommend specific strategies and approaches. In addition, our reflections on current methodological challenges serve as a starting point for discussions in communication science on how meaning-making between humans and machines can be investigated in the best way possible, as illustrated in the concluding section

Endocrine profiles during administration of the new non-steroidal anti-androgen Casodex in prostate cancer

OBJECTIVE Casodex (Zeneca) is a new potent, long-acting non-steroidal anti-androgen, which produces androgen deprivation by blocking the androgen receptor. We evaluated the endocrine effects of Casodex 150 mg daily given in monotherapy as primary treatment for patients with prostate cancer. DESIGN As part of a large, multicentre study comparing the therapeutic effects of surgical castration with 150 mg/day Casodex in monotherapy for patients with prostate cancer, a subgroup of 23 patients on Casodex were studied in detail for changes in endocrine parameters. Serum levels of LH, FSH, testosterone, DHT, oestradiol, prolactin, sex hormone binding globulin and free testosterone were measured at the start of therapy and after 1, 4, 8, 12 and 24 weeks. Effects on libido, sexual activity and the appearance of hot flushes, breast pain and gynaecomastia were recorded. RESULTS Administration of Casodex resulted in a rise in LH levels in all patients with a mean increase after 24 weeks of 102% (P < 0.001). Mean FSH levels showed a limited increase (7%) after 24 weeks, which was significant only after 1 week (P < 0.001). As a result of the high LH levels, total testosterone levels increased after 24 weeks by 66% (P < 0.001), free testosterone by 57% (P < 0.001) and dihydrotestosterone by 24% (P = 0.0112). Parallel to testosterone, oestradiol levels rose by a mean of 66% (P < 0.001). Mean sex hormone binding globulin and prolactin levels rose by respectively 8% (P = NS) and 65% (P < 0.01). Despite an increase in testosterone levels, excellent androgen blockade was obtained, as shown by a decrease in prostate specific antigen levels in 22/23 patients. Libido was maintained in 8/11 patients, and sexual activity in 5/6. No patient complained of hot flushes. However, mild gynaecomastia and/or breast tenderness were seen in 48 and 30% of cases respectively. CONCLUSION Casodex 150 mg/day monotherapy resembles surgical castration in achieving androgen deprivation, despite an increase in LH and testosterone levels. In contrast to castration, libido and sexual activity are usually maintained and hot flushes are rare. However, mild gynaecomastia and/or breast tenderness were noted in 48 and 30% of patients

Implementing cryptographic pairings at standard security levels

This study reports on an implementation of cryptographic pairings in a general purpose computer algebra system. For security levels equivalent to the different AES flavours, we exhibit suitable curves in parametric families and show that optimal ate and twisted ate pairings exist and can be efficiently evaluated. We provide a correct description of Miller's algorithm for signed binary expansions such as the NAF and extend a recent variant due to Boxall et al. to addition-subtraction chains. We analyse and compare several algorithms proposed in the literature for the final exponentiation. Finally, we give recommendations on which curve and pairing to choose at each security level.Algorithmic Number Theory in Computer Scienc