Privacy versus Information in Keystroke Latency Data

The computer science education research field studies how students learn computer science related concepts such as programming and algorithms. One of the major goals of the field is to help students learn CS concepts that are often difficult to grasp because students rarely encounter them in primary or secondary education. In order to help struggling students, information on the learning process of students has to be collected. In many introductory programming courses process data is automatically collected in the form of source code snapshots. Source code snapshots usually include at least the source code of the student's program and a timestamp. Studies ranging from identifying at-risk students to inferring programming experience and topic knowledge have been conducted using source code snapshots. However, replicating source code snapshot -based studies is currently hard as data is rarely shared due to privacy concerns. Source code snapshot data often includes many attributes that can be used for identification, for example the name of the student or the student number. There can even be hidden identifiers in the data that can be used for identification even if obvious identifiers are removed. For example, keystroke data from source code snapshots can be used for identification based on the distinct typing profiles of students. Hence, simply removing explicit identifiers such as names and student numbers is not enough to protect the privacy of the users who have supplied the data. At the same time, removing all keystroke data would decrease the value of the data significantly and possibly preclude replication studies. In this work, we investigate how keystroke data from a programming context could be modified to prevent keystroke latency -based identification whilst still retaining valuable information in the data. This study is the first step in enabling the sharing of anonymized source code snapshots. We investigate the degree of anonymization required to make identification of students based on their typing patterns unreliable. Then, we study whether the modified keystroke data can still be used to infer the programming experience of the students as a case study of whether the anonymized typing patterns have retained at least some informative value. We show that it is possible to modify data so that keystroke latency -based identification is no longer accurate, but the programming experience of the students can still be inferred, i.e. the data still has value to researchers

Sizing the auxiliary system capacities for a pilot plant project

Opinnäytetyö on osa Stora Enso Oy:n projektia, jonka tarkoituksena on rakentaa Sunilan tehdasalueelle pilotmittakaavan tehdas ligniinin jatkojalostusta varten. Jatkojalostuksen tarkoituksena on parantaa ligniinin ominaisuuksia, niin että se voisi korvata fossiilipohjaisia materiaaleja tulevaisuudessa. Opinnäytetyö keskittyi käyttöhyödykejärjestelmien suunnittelun ympärille. Tarkoituksena oli selvittää jäähdytysvesijärjestelmän, typpijärjestelmän ja savukaasujenkäsittelyjärjestelmän vaatimukset ja niiden perusteella mitoittaa järjestelmät. Työ toteutettiin keräämällä aineistoa päälaitteina toimivista lämpökäsittelyuuneista. Nämä laitteet määrittelevät tärkeimmät vaatimukset apujärjestelmille. Kerättyä ainestoa analysoitiin ja erilaitteiden vaatimuksia vertailtiin, jotta voitiin määritellä järjestelmälle yhtenäiset vaatimukset. Vaatimusten määrittelyn jälkeen sopivan ratkaisun valinnassa hyödynnettiin kirjallisuutta, tutkimustietoa ja apujärjestelmätoimittajien tietotaitoa. Typpijärjestelmäksi valittiin PSA-teknologialla toimiva generaattori, koska se oli kustannustehokkain järjestelmä, joka pystyi täyttämään vaatimukset. Kompressoriksi järjestelmälle valittiin öljytönruuvikompressori. Järjestelmä varustettiin tarvittavilla säiliöllä ja puhdistuslaitteilla. Savukaasujen käsittelyjärjestelmän osalta päädyttiin ratkaisuun, joka sisälsi kaksi erillistä polttokammiota. Päälaitevalmistajat suunnittelevat ja toimittavat molemmat polttokammiot. Jäähdytysvesijärjestelmäksi suunniteltiin suljetuksi kierroksi. Suljettukierto vaatii lämmönvaihtimen, jäähdytysteholtaan n.200kW, jotta nesteen lämpötila pysyy tasaisena. Järjestelmien mitoituksen tarkkuuteen vaikuttivat lähtötietojen vähäisyys ja salassapitoasiat sekä referenssien puute. Nämä ovat tyypillisiä ongelmia pilotprojekteille. Suurin osa saaduista tuloksista on luotettavia ja niitä voidaan hyödyntää myöhemmin prosessisuunnittelussa.The thesis is a part of a Stora Enso’s project. The objective of the project is to build a pilot-scale plant where lignin can be processed. The aim of processing lignin is to improve its properties so that it can replace fossil-based materials in the future. The thesis focused on the design of auxiliary systems. The main objectives of the thesis were to determine the re-quirements for the nitrogen supply system, the exhaust gas treatment system, and the cool-ing water system and to select suitable equipment based on these requirements. The study was done by gathering material from heat treatment furnaces which are the main equipment of the process. The technical data of the furnaces provided the main require-ments for the auxiliary systems. The material was analyzed and the requirements from each furnace were compared with each another so that uniform requirements could be made for the systems. Once the requirements were set, literature, studies, and the knowledge of the auxiliary system suppliers were utilized to select the equipment for the systems. A generator with PSA-technology was chosen for the nitrogen supply system because it was found to be the most cost-efficient solution that met the requirements. An oil-free screw-compressor was selected as a compressor for the system. The system is equipped with the necessary vessels and cleaning equipment. For the exhaust gas treatment system, the solu-tion included two separate combustion chambers. The main equipment manufacturers de-sign and supply both combustion chambers. The cooling water system was designed to have a closed loop. The closed loop requires a heat exchanger with 200kW cooling power to keep the water temperature inside the loop stable. The scarcity and secrecy of the data, as well as the lack of references, affected the sizing accuracy of the systems. These are normal prob-lems for a pilot-project. However, most of the results are reliable and these results can be utilized in the process design

Can Students Review Their Peers?: Comparison of Peer and Instructor Reviews

Having students peer review each other's exercises is a common task in modern computing classrooms. In large classes, peer review might even partly replace traditional instructor-led review -- and prior work has found some indications that the quality of peer reviews can be close to that of instructor reviews. In this work, we explore the difference between instructor and peer reviews of student-created programming exercises. One task in an introductory programming course was to have students design their own programming exercises -- including an exercise description, model solution, and test cases -- which were then reviewed by peers. After the course, we had two instructors review the same student-created exercises. We compare the scores given by the instructors and the students to analyze potential differences. Our results suggest that agreement between instructors and students as measured by inter-rater reliability is low, although differences between instructor and student review score distributions are not statistically significant. Additionally, instructors have more fluctuation in their reviews compared to students. Due to the rising popularity of peer reviews, more research is needed to examine to what extent they could complement traditional instructor-led review of exercises.Peer reviewe

Thought crimes and profanities whilst programming

Where should we draw the line of inappropriate conduct on a course that is given freely to anyone? If an individual starts profusely swearing on a lecture, they are most likely expelled from the class or even from the course. But what if they do it outside the lecture amongst their classmates, amongst a group of anonymous individuals - or by themselves? In this article, we study how students use profanities in source code when they are completing programming assignments on a massive open online course (MOOC). We examine how common it is to curse in source code as well as whether specific assignments incite more cursing than others. Additionally, we investigate differences between participants with regards to cursing. Our results indicate that a considerable amount of participants write curse words whilst programming, but most clean their code for the final submission. The data also shows that there are different degrees of profanity in use, ranging from quite inoffensive words to offensive racial slurs. Finally, we discuss options that one may take when individuals who swear are identified, starting from rescinding their right to study.Peer reviewe

Kunnallisen tilintarkastuksen laadunvalvonta erityisesti asiakasvalvonnan näkökulmasta

Laadukas tilintarkastus on tärkeää kunnille ja niiden veronmaksajille. Tilintarkastuksen laadunvalvonnalla pyritään varmistamaan tilintarkastuspalvelun riittävä taso. Tilintarkastus on kuitenkin luonteeltaan palvelu, jonka laadun määritteleminen on melko haastavaa ja monitulkintaista. Kunnallisen tilintarkastuksen laadunvalvonta voidaan jakaa kolmeen päähaaraan: JHTT-lautakunnan suorittamaan laadunvalvontaan, tilintarkastusyhteisöjen omavalvontaan ja kuntien tilintarkastuspalvelun asiakkaina suorittamaan laadunvalvontaan. Tässä tutkimuksessa paneuduttiin siihen, miten kunnissa ymmärretään tilintarkastuksen laatu, ja kuinka kunnat tilintarkastuspalvelun asiakkaina voivat suorittaa tilintarkastuksen laadunvalvontaa. Tutkimukseen haastateltiin kolmea pirkanmaalaisen kunnan tarkastuslautakunnan puheenjohtajaa tai varapuheenjohtajaa. Lisäksi aineistona hyödynnettiin samaisten kuntien tilintarkastuspalvelujen tarjouspyyntöjä. Tutkimuksen perusteella tilintarkastuksen laatu ymmärretään tapauskunnissa melko konservatiivisella tavalla. Laatuun vaikuttavia osatekijöitä ovat luotettavuus, huolellisuus, ammattitaito sekä kohtuullinen hinta. Lisäksi tärkeäksi koettiin tilintarkastajaan henkilönä liittyvät ominaisuudet, kuten aloitteellisuus ja yhteistyökykyisyys. Tilintarkastuksen laadunvalvonta koettiin kunnissa tärkeäksi. Tutkimuksen perusteella laadunvalvonnassa tärkeässä asemassa on jo tarjouspyyntö, jonka avulla riittävä laatutaso pyritään varmistamaan jo tilintarkastuspalvelun kilpailuttamisvaiheessa. Asiakassuhteen aikana tilintarkastuksen laatua valvotaan mm. edellyttämällä työohjelman hyväksyttämistä tarkastuslautakunnassa, tarkastushavaintojen raportointia, osallistumista tarkastuslautakunnan kokouksiin sekä antamalla erityisiä ohjeita tarkastusten suorittamisesta. Tutkimuksen perusteella laadunvalvonnassa koettiin myös olevan ongelmia. Haasteena mainittiin tarkastuslautakunnan jäsenten puutteellinen asiantuntemus tilintarkastuksesta, jonka johdosta heidän tosiasialliset mahdollisuutensa suorittaa laadunvalvontaa ovat puutteelliset. Luottamus tilintarkastajiin ja alan sääntelyyn sekä ulkoiseen valvontaan, kuten JHTT-lautakuntaan todettiin kuitenkin hyvin korkeaksi. Avainsanat: tilintarkastuksen laatu, laadunvalvonta, kunta, tarkastuslautakunt

Persistence of Time Management Behavior of Students and Its Relationship with Performance in Software Projects

Teachers often preach for their students to start working on assignments early. There is even a fair amount of scientific evidence that starting early is beneficial for learning. In this work, we investigate students’ time management behavior in a second-year project-based software engineering course. In the course, students work on a software project in small groups of four to six students. We study time management from multiple angles. Firstly, we conduct an exploratory factor analysis and study how different time management related behavioral metrics are related to one another, for example, whether individual students’ time management practices in the second-year group project-based course are similar to their earlier time management practices in first-year courses where students work on assignments individually. Understanding how students’ previous time management behavior is manifested in later project-based courses would be beneficial when designing project-based education. Secondly, we study whether students’ time management practices affect the peer-review scores they get from their group members. Lastly, we explore how time management affects course performance. Our findings suggest that time management behavior, even from courses taken in the past, can be used to predict how students perform in future courses.Peer reviewe

Exploring the Applicability of Simple Syntax Writing Practice for Learning Programming

When learning programming, students learn the syntax of a programming language, the semantics underlying the syntax, and practice applying the language in solving programming problems. Research has suggested that simply the syntax may be hard to learn. In this article, we study difficulty of learning the syntax of a programming language. We have constructed a tool that provides students code that they write character-by-character. When writing, the tool automatically highlights each character in code that is incorrectly typed, and through the highlight-based feedback directs students into writing correct syntax. We conducted a randomized controlled trial in an introductory programming course organized in Java. One half of the population had the tool in the course material immediately before programming exercises where the practiced syntax was used, while the other half of the course population did not have the tool, thus approaching the exercises in a traditional way. Our results imply that isolated syntax writing practice may not be a meaningful addition to the arsenal used for teaching programming, at least when the programming course utilizes a large set of small programming exercises. We encourage researchers to replicate our work in contexts where syntax seems to be an issue.Peer reviewe

A Study of Keystroke Data in Two Contexts : Written Language and Programming Language Influence Predictability of Learning Outcomes

We study programming process data from two introductory programming courses. Between the course contexts, the programming languages differ, the teaching approaches differ, and the spoken languages differ. In both courses, students' keystroke data -- timestamps and the pressed keys -- are recorded as students work on programming assignments. We study how the keystroke data differs between the contexts, and whether research on predicting course outcomes using keystroke latencies generalizes to other contexts. Our results show that there are differences between the contexts in terms of frequently used keys, which can be partially explained by the differences between the spoken languages and the programming languages. Further, our results suggest that programming process data that can be collected non-intrusive in-situ can be used for predicting course outcomes in multiple contexts. The predictive power, however, varies between contexts possibly because the frequently used keys differ between programming languages and spoken languages. Thus, context-specific fine-tuning of predictive models may be needed.Peer reviewe

Supporting Self-Regulated Learning with Visualizations in Online Learning Environments

In this article, we study how visualizations could be used to support students' self-regulation in online learning. We conducted a randomized controlled trial with three groups: one control group without visualization, one treatment group with textual visualization, and one treatment with graphical visualization with information on peers' average achievement. We studied how different visualizations affect students' academic performance and behavior. We focused on four factors; starting, scheduling, earliness and exercise points, where the first three are related to time management and self-regulation. The last factor measures course performance in terms of completed exercises. Our results suggest that the lowest performing students can benefit from a visualization, whereas the highest performing students are not affected by the presence or absence of a visualization. We also found that visualizations that do not provide the means to compare your own performance with others may even be harmful to performance oriented students.Peer reviewe