Abstract. Understanding and analyzing collaborative learning processes require a fine-grained sequential analysis of the group interaction in the context of learning goals. Several researchers in the area of cooperative work take as a success criterion the quality of the group outcome. Nevertheless, recent findings are giving importance to the quality of the cooperation process itself. This paper presents a set of indicators which main objective is to evaluate the collaborative learning process. We have defined an experiment with a tool instrumented to gather data from groups working in a simple task. This data is then useful to build the cooperation indicators, which in turn allow us to estimate the quality of the work process.

Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user's trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

Natural user interfaces are becoming popular. One of the most common natural user interfaces nowadays are voice activated interfaces, particularly smart personal assistants such as Google Assistant, Alexa, Cortana, and Siri. This paper presents the results of an evaluation of these four smart personal assistants in two dimensions: the correctness of their answers and how natural the responses feel to users. Ninety-two participants conducted the evaluation. Results show that Alexa and Google Assistant are significantly better than Siri and Cortana. However, there is no statistically significant difference between Alexa and Google Assistant.

: There is a tendency to reduce the amount of NaCl in the manufacturing process of Spanish dry-cured ham. NaCl, pH and temperature determine the stability of this product. This study was concerned with the evaluation of green ham pH and sodium chloride concentration on cathepsin activities, physico-chemical parameters and sensory characteristics of dry-cured hams. Two di †erent amounts of salt (55 and 80 g kg~1) and two di †erent pH levels (pH at 24 h post mortem \5É8 ; pH at 24 h post mortem [6É2) were used. Physicochemical composition, cathepsin activity and a number of sensory parameters were evaluated. Hams with high pH displayed lower cathepsin activity, NPN, saltiness and hardness whereas the levels of brightness, crumbliness, pastiness and adhesivity were found to be higher than in normal hams. A high level of salt produced greater cathepsin B and B ] L activity and lower pastiness and adhesivity than the samples with a low NaCl level.1998 SCI. ( J Sci Food Agric 77, 387È392 (1998)

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