In the thesis, I focus on the relationship between visual memory and the ability to detect changes in photographs. In the theoretical part I introduce the change detection and "change blindness" phenomenon. Next, this work explores visual memory and refers to studies that focused on visual long-term memory and its role in change detection. The objective of the empirical part of this thesis is to map the relation between visual memory (scene memorability) and change detection illustrated on the ability to recognize changes in photographs of indoor and outdoor scenes. Research was conducted by means of an experiment devised in PsychoPy using flicker paradigm. The research sample comprised 42 respondents, mainly university students. Research results did not confirm the existence of a relation between visual memory and change detection. No correspondence was found between these variables, not even at the level of each category, suggesting that change detection depends on other factors than visual long-term memory. KEYWORDS: Change blindness, visual long-term memory, change detection, memorability, perception, experiment

Several museums and science centers around the world are investigating how to increase interest in scientific subjects among children. One way to increase a person's commitment and interest in science is to start a conversation about it. This thesis examines how illustrations in exhibition signs at Tom Tits Experiment can add more knowledge about the science behind the experiment the gyro wheel. The signs are primarily aimed at the adult visitors, who in turn want to be able to explain what the experiment means to their children. The illustrations are meant to be easy to remember and provide knowledge about the gyroscope and the areas of use of the gyroscopic effect in everyday life. The results of the study showed that as long as the information is perceived as interesting by the users, then that could be enough in order to engage and arouse their interest. The illustrations themselves did not have to be complicated or exaggerated for visitors to remember them and want to talk about them. / Ett antal museum och science centers världen över undersöker hur man kan öka intresset för teknik och naturvetenskap hos barn. Ett sätt att öka en persons engagemang och intresse för ämnesområdena är att börja samtala om dem. I detta examensarbete undersöks hur illustrationer i utställningskyltar på Tom Tits Experiment kan tillföra mer kunskaper kring vetenskapen bakom experimentet gyrohjulet. Skyltarna riktar sig i första hand till de vuxna besökarna som i sin tur vill kunna förklara vad experimenten innebär för sina barn. Illustrationerna är skapade för att vara lätta att minnas och ge kunskaper om gyroskopet och gyrokraftens användningsområden i vardagliga sammanhang. Resultatet av studien visade att för att väcka engagemang och intresse hos användarna kan det räcka med att informationen i skylten upplevs som intressant av besökarna. Illustrationerna behövde inte vara komplicerade eller överdrivna för att besökarna skulle minnas dem och vilja samtala om dem.

The focus of this report is to discuss graphical password systems and how they can contribute to handle security problems that threaten authentication processes. One such threat is shoulder-surfing attacks, which are also reviewed in this report. Three already existing systems that are claimed to be shoulder-surfing resilient are described and a new proposed system is presented and evaluated through a user study. Moreover, the system is compared to the mentioned existing systems to further evaluate the usability, memorability and the time it takes to authenticate. The user study shows that test subjects are able to remember their chosen password one week after having registered and signed in once. It is also shown that the average time to sign in to the system after five minutes of practice is within a range of 3.30 to 5.70 seconds. The participants in the experiments gave the system an average score above 68 on the System Usability Scale, which is the score of an average system.

L’étude de la rétroaction corrective constitue un enjeu important dans la recherche en didactique des langues et a été en partie renouvelée par l’utilisation des technologies. Or, peu de recherches se sont penchées sur la manière dont les enseignants fournissent une rétroaction corrective sur la production orale des apprenants lors d’interactions en ligne. C’est pourquoi nous nous proposons d’analyser six semaines d’interactions entre des apprentis enseignants en formation dans un master de didactique de français langue étrangère (désormais FLE) d’une université française (Lyon 2) et des apprenants de FLE d’une université étrangère (DCU). Notre étude relevant d’une recherche qualitative s’appuie un corpus complexe comprenant des interactions en ligne transcrites et annotées au moyen du logiciel ELAN, des bilans multimodaux réalisés par les enseignants et les discours des participants. Nous avons analysé ces données dans une perspective multimodale selon laquelle toutes les ressources sémiotiques contribuent à produire du sens, sans hiérarchisation de celles-ci a priori. En somme, ce travail vise à étudier les effets de la multimodalité sur la manière dont les apprentis enseignants et les apprenants coconstruisent les séquences de rétroactions correctives en ligne afin, dans un deuxième temps, de faire des propositions didactiques pour la formation. / This work aims to analyze six weeks of videoconferenced pedagogical interaction between trainee teachers enrolled in a master's degree in teaching French as a foreign language (FLE) at a French university (Lyon 2) and learners of French at a foreign university (Dublin City University). Corrective feedback is an important issue in foreign language pedagogy, renewed by the use of technologies. However, there has been little research on how teachers provide corrective feedback on learners' oral production in online interactions. Our qualitative study is based on the analysis of ecological data, organized into a complex corpus of video interactions transcribed and annotated using the ELAN software. We observed multimodal assessments made by the teachers, as well as participants' commentary containing their perception of the corrective feedback. We analyzed these data from a multimodal perspective according to which all the semiotic resources contribute to make meaning without automatically prioritizing one mode over another. In sum, this work aims to understand how teachers and learners co-construct corrective feedback sequences. We also want to update the effects of multimodality on the interactions in order to make pedagogical proposals for the training of future teachers of French as a foreign language.