Directory

Amber Settle - Academia.edu

Skip to main content

Amber Settle

Followers

29

Following

12

Co-authors

11

Public Views

University of Chicago

Jean-Baptiste Yunès

Université Paris Diderot

University of Salerno

Melanie Mitchell

Portland State University

Carnegie Mellon University

Mitsunori Ogihara

University of Miami

Maurice Margenstern

Interests

Uploads

Papers by Amber Settle

Bounding the firing synchronization problem on a ring

Theoretical Computer Science, Jun 1, 2004

In this paper we improve the upper and lower bounds on the complexity of solutions to the firing ... more In this paper we improve the upper and lower bounds on the complexity of solutions to the firing synchronization problem on a ring. In this variant of the firing synchronization problem the goal is to synchronize a ring of identical finite automata. Initially, all automata are in the same state except for one automaton that is designated as the initiator for the synchronization. The goal is to define the set of states and the transition function for the automata so that all machines enter a special fire state for the first time and simultaneously during the final round of the computation. In our work we present two solutions to the ring firing synchronization problem, an 8-state minimal-time solution and a 6-state non-minimal-time solution. Both solutions use fewer states than the previous best-known minimal-time automaton, a 16-state solution due to Culik. We also give the first lower bounds on the number of states needed for solutions to the ring firing synchronization problem. We show that there is no 3-state solution and no 4-state, symmetric, minimal-time solution for the ring.

File references, trees, and computational thinking

We study student understanding of the use of a tree structure in the context of an introductory w... more We study student understanding of the use of a tree structure in the context of an introductory web development course. In particular, we analyze student answers as they use a tree structure to construct file references in web pages. More fundamentally, our study initiates a bottom-up study of computational thinking by identifying the computational thinking mistakes that students make when they are learning resource referencing for web development. Our preliminary results suggest that students do not necessarily learn abstract concepts (like trees) and abstract rules of reasoning (composing relative and absolute tree paths) by just working with folders and composing file references alone.

Learning Object-Oriented Programming in Python

We report a small yet detailed study where we recorded students completing an object-oriented pro... more We report a small yet detailed study where we recorded students completing an object-oriented programming exercise in the context of a CS2 course using Python. All students struggled while completing the assignment, most notably experiencing difficulties with parameters and referencing elements with object-dot notation. While previous research has identified these areas as troublesome for novice programmers, our analysis suggests that parameters and reference specifications are particularly critical prerequisites for learning advanced object-oriented concepts with the Python programming language. Given our findings, we recommend extensive practice with parameter passing and object-dot notation before addressing advanced object-oriented concepts in a Python course.

Undergraduate Students’ Perceptions of the Impact of Pre-College Computing Activities on Choices of Major

ACM Transactions on Computing Education, Jun 9, 2016

A lack of diversity in the computing field has now existed for several decades, and while female ... more A lack of diversity in the computing field has now existed for several decades, and while female participation in computing remains low, outreach programs attempting to address the situation are now quite numerous. To begin to understand whether or not these past activities have had long-term impact, we conducted a systematic literature review. Upon discovering that longitudinal studies were lacking, we investigated whether undergraduate students believed that their participation in computing activities prior to college contributed to their decision to major in a computing field. From the 770 participants in the study, we discovered that approximately 20% of males and 24% of females who were required to participate in computing activities chose a computing or related major, but that males perceived that the activity had a greater affect on their decision (20%) than females (6.9%). Females who participated in an outreach activity were more likely to major in computing. Female respondents who did not major in computing in college were less likely than those females who did to indicate that a majority of students participating in pre-college computing activities were boys and that they were a welcome part of the groups participating in the activities. Results also showed that female participants who do not ultimately major in computing have a much stronger negative perception of the outreach activities than male participants who also chose a non-computing major. Although many computing outreach activities are designed to diversify computing, it may be the case that overall boys receive these activities more favorably than girls, although requiring participation yields approximately the same net positive impact.

Research Directions for Teaching Programming Online

ABSTRACT Online education has a long-standing tradition in academia, and yet online programming r... more ABSTRACT Online education has a long-standing tradition in academia, and yet online programming remains a relatively undeveloped area in the computing education literature. This is in sharp contrast with in-person programming courses, which have been a favorite subject of study in computing education. Research into teaching on-site programming is so extensive that numerous practices have emerged and are typically supported by instructional theory, empirical results or both. In this article we identify some of the commonly accepted practices for teaching programming in an on-site environment and survey the work that has been done for online programming. In doing so, we contrast the rigor of on-site programming research with the relative immaturity of educational practices for online programming. We identify research questions and future directions for online programming educators, with the goal of inspiring the same high-quality work that on-site programming research has produced.

Game Design as a Writing Course in the Liberal Arts

International Conference on Frontiers in Education, 2007

The School of Computer Science, Telecommunications, and Information Systems (CTI) is a technologi... more The School of Computer Science, Telecommunications, and Information Systems (CTI) is a technologically-focused college within DePaul University. While DePaul CTI has a large number of technical degree programs, DePaul University is a liberal arts institution and one that is increasingly focused on improving the writing skills of its students. It can be difficult to create courses that cover necessary technical material while requiring writing as a major part of the assessments. In this paper we discuss GAM 224: Introduction to Game Design, a required course in one of the specialized degree programs at DePaul CTI that involves writing in a significant way.

Computational Thinking Across the Curriculum: A Conceptual Framework

• Recollection is the encoding and organization of data in ways to make it efficient to search an... more

Does lecture capture make a difference for students in traditional classrooms

The College of Computing and Digital Media (CDM) at DePaul University has recorded thousands of c... more The College of Computing and Digital Media (CDM) at DePaul University has recorded thousands of courses using an in-house system called Course Online (COL) since 2001. These recordings are available not only to students enrolled in online CDM courses, but also to students in traditional classrooms at CDM. In this study we analyzed survey responses and grade data to determine

A Framework for Addressing Gender Imbalance in the Game Industry through Outreach

Advances in human and social aspects of technology book series, 2014

Though the lack of diversity in the game industry workforce has received a great deal of attentio... more Though the lack of diversity in the game industry workforce has received a great deal of attention recently, few initiatives have been implemented to address it. In particular, gender composition in the game industry workforce and among students studying games at post-secondary institutions is highly imbalanced, with an approximate 9 to 1 ratio of male to female students. This chapter considers three key aspects: 1) the current demographics of the game industry, 2) the effects of gender imbalance on the game industry and one of its current pipelines, and 3) a potential framework to address the imbalance. The proposed outreach strategy is informed by a discussion of established frameworks for initiating change in related fields. The chapter concludes with suggestions for future research to address the gender imbalance in the game industry and its pipeline

Non-Minimal Time Solutions for the Firing Sychronization Problem

The firing synchronization problem concerns a one-dimensional array of $n$ finite automata. All a... more The firing synchronization problem concerns a one-dimensional array of $n$ finite automata. All automata are identical, except the ones on either end of the array, one of which is the initiator for the synchronization. The goal is to define the set of states and transition rules for the automata so that all machines enter a special fire state for the first time and simultaneously at some time $t(n)$. The generalized firing synchronization problem differs from the original problem in that the initiator of the synchronization can be located anywhere in the array. In this paper we present two non-minimal time solutions to the firing synchronization problem. The first is a 6-state solution to the original problem which allows the initiator to be located at either the right or left endpoint. This automaton has two fewer states than R.~Balzer''s 8-state minimal-time automaton \cite{b}, the minimal-time automaton with the smallest number of states that allows the initiator to be located at either endpoint. We also give a 7-state non-minimal time solution to the generalized problem. No previous non-minimal time solutions to the generalized firing synchronization problem have been published, and the smallest minimal-time automaton for the generalized problem requires 9 states \cite{s9}. Both automata are based on the 6-state minimal-time solution to a restricted version of the original problem given by J.~Mazoyer \cite{m6}. Finally, we provide a proof of correctness for each of the automata.

Improved bounds for the firing synchronization problem

In this pa per we prese nt improve d bounds on the comple xity of solutions to the ¿ ring synchro... more In this pa per we prese nt improve d bounds on the comple xity of solutions to the ¿ ring synchroniza tion problem. In the ¿ ring synchronization proble m we consider a one-dime nsional a rray of n identica l ¿ nite a utoma ta. Initia lly all a utoma ta a re in the same sta te e xcept for one automaton which is designa te d a s the initia tor for the synchroniza tion. Our re sults hold for the origina l problem, whe re the initia tor may be located a t eithe r e ndpoint, and for the va ria nt whe re any one of the automata ma y be the initiator, ca lle d the ge nera lize d problem. In both ca ses, the goa l is to de ¿ ne the set of sta te s a nd transition rule s for the a utoma ta so tha t a ll machine s e nte r a specia l ¿ re state simultaneously and for the ¿ rst time during the ¿ na l round of the computation. In our work we improve the construction for the best known minima l-time solution to the ge nera lize d problem by re ducing the number of sta te s nee ded and give non-minima l time solutions to the original and ge nera lize d proble m which use fewer states tha n the corresponding minima l-time solutions.

Learning to Get Literal

ACM Transactions on Computing Education, May 29, 2019

We investigate conditions in which novices make some reference errors when programming. We asked ... more We investigate conditions in which novices make some reference errors when programming. We asked students from introductory programming courses to perform a simple code-writing task that required constructing references to objects and their a ributes. By experimentally manipulating the nature of the a ributes in the tasks, from identifying a ributes (e.g. title or label) to descriptive a ributes (e.g. calories or texture), the study revealed the relative frequencies with which students mistakenly omit the name of an identifying a ribute while a empting to reference its value. We explain how these reference-point shi s are consistent with the use of metonymy, a form of gurative expression in human communication. Our analysis also reveals how the presentation of examples can a ect the construction of the reference in the student's solution. We discuss plausible accounts of the reference-point errors and how they may inform a model of reference construction. We suggest that reference-point errors may be the result of well practiced habits of communication rather than misconceptions of the task or what the computer can do.

Smaller solutions for the firing squad

Theoretical Computer Science, Apr 1, 2002

In this paper we improve the bounds on the complexity of solutions to the¯ring squad problem, als... more In this paper we improve the bounds on the complexity of solutions to the¯ring squad problem, also known as the¯ring synchronization problem. In the¯ring synchronization problem we consider a one-dimensional array of n identical¯nite automata. Initially all automata are in the same state except for one automaton designated as the initiator for the synchronization. Our results hold for the original problem, where the initiator may be located at either endpoint, and for the variant where any one of the automata may be the initiator, called the generalized problem. In both cases, the goal is to de¯ne the set of states and transition rules for the automata so that all machines enter a special re state simultaneously and for the¯rst time during the¯nal round of the computation. In our work we improve the construction for the best known minimal-time solution to the generalized problem by reducing the number of states needed and give non-minimaltime solutions to the original and generalized problem that use fewer states than the corresponding minimal-time solutions.

Concepts in K-9 Computer Science Education

If citing, it is advised that you check and use the publisher's definitive version for pagination... more If citing, it is advised that you check and use the publisher's definitive version for pagination, volume/issue, and date of publication details. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher's website for any subsequent corrections.

Computational Thinking in K-9 Education

Mixing and Matching Loop Strategies: By Value or By Index?

Proceedings of the 52nd ACM Technical Symposium on Computer Science Education, 2021

Increasingly, languages used in computing curricula offer abstract constructs that permit list it... more Increasingly, languages used in computing curricula offer abstract constructs that permit list iteration by value, in addition to the traditional access by index. Given this option, this study explores the loop constructs students choose when solving a problem. We asked students from introductory programming courses to write solutions to two tasks that require iteration through array or list objects, analyzing their responses and noting coding constructs that indicate a loop-by-value strategy or a loop-by-index strategy. Consistent with previous accounts, we find that students may employ a strategy based on their experience and the required task. However, they often implement the strategy using code elements that are inconsistent with the chosen strategy, including referencing the index when a reference to the value at the location of the index is required. Some inconsistencies, such as the use of misleading variable names, do not affect program execution but often coincide with other inconsistencies that produce incorrect code. We recommend that instructors provide explicit scaffolding for the sequential introduction of iterative constructs. We note that a discussion of when each type of loop is typically used may be insufficient and suggest reinforcing habits for maintaining and checking consistency of looping strategies.

Towards a Common Framework for Evaluating Computing Outreach Activities

Proceedings of the 47th ACM Technical Symposium on Computing Science Education, 2016

In the past six years, dozens of conference papers and journal articles have been presented in As... more In the past six years, dozens of conference papers and journal articles have been presented in Association of Computing Machinery (ACM) and Institute of Electrical and Electronics Engineers (IEEE) educational forums concerning computing outreach activities. Nearly half of these (47.5%) appeared in SIGCSE venues. In this study, we used the free-form question "What type of data has been collected in formal, peer-reviewed research that has been conducted on computing outreach activities in recent years?" as a basis for a systematic literature review in these venues from 2009-2015. During the analysis of the articles, it was discovered that a majority of efforts focused on middle school and high school students, a majority of the reported events took place in the United States, and almost half had a goal of increasing gender diversity in computing. This paper summarizes the information about the studies, including their data collection techniques and the data that was collected. We also present a list of recommended practices for data collection, methodologies, and reporting for educational researchers engaged in these activities in an effort to provide comparative data and allow us as a community to more scientifically understand the impact that these activities are having on the participants.

Computing outreach literature review

2015 Research in Equity and Sustained Participation in Engineering, Computing, and Technology (RESPECT), 2015

The lack of diversity in computing has existed for decades. It has garnered the attention of comp... more The lack of diversity in computing has existed for decades. It has garnered the attention of computing educators and private companies who have implemented a host of outreach and retention programs to draw more diverse students into the field and the workforce. A question that stands out is whether or not these programs are effective in the long term in helping to mitigate the lack of diversity in the field. To determine an answer to this question, the authors undertook a systematic literature review of reported computing outreach activities in relevant journals and conference proceedings for the years 2009-2014 inclusive. Upon consideration of all relevant articles, 73 articles were coded for information about the type of outreach, target audience, and reported results. Summaries of the findings of the literature review are presented in this poster.

Learning Object-Oriented Programming in Python

Proceedings of the 16th Annual Conference on Information Technology Education, 2015

We report a small yet detailed study where we recorded students completing an object-oriented pro... more We report a small yet detailed study where we recorded students completing an object-oriented programming exercise in the context of a CS2 course using Python. All students struggled while completing the assignment, most notably experiencing difficulties with parameters and referencing elements with object-dot notation. While previous research has identified these areas as troublesome for novice programmers, our analysis suggests that parameters and reference specifications are particularly critical prerequisites for learning advanced object-oriented concepts with the Python programming language. Given our findings, we recommend extensive practice with parameter passing and object-dot notation before addressing advanced object-oriented concepts in a Python course.

Does Outreach Impact Choices of Major for Underrepresented Undergraduate Students?

Proceedings of the eleventh annual International Conference on International Computing Education Research, 2015

Over the last decade, there has been a concerted effort to bring more diverse voices to the techn... more Over the last decade, there has been a concerted effort to bring more diverse voices to the technology field, with much of this being done through outreach activities to girls and boys. Unfortunately, data demonstrating the long-term impact of outreach activities remains rare. To contribute to knowledge on the longitudinal effect of outreach programs, we used a quantitative methodology that followed a descriptive design approach to explore the impact of participation in outreach activities on the choice of undergraduate major. Of those surveyed, 45.3% of the 770 respondents recalled participating in these activities. The results indicate that these activities had a more positive impact on Asians and more negative impact on Hispanics. Blacks/African Americans were more likely to voluntarily participate in outreach activities than Hispanics, and whites were more likely to feel that they were a welcome part of the group than non-whites. The results also may indicate that when outreach programs are available in earlier grades, they are not reaching non-white participants to the same extent as white participants.

Bounding the firing synchronization problem on a ring

Theoretical Computer Science, Jun 1, 2004

In this paper we improve the upper and lower bounds on the complexity of solutions to the firing ... more In this paper we improve the upper and lower bounds on the complexity of solutions to the firing synchronization problem on a ring. In this variant of the firing synchronization problem the goal is to synchronize a ring of identical finite automata. Initially, all automata are in the same state except for one automaton that is designated as the initiator for the synchronization. The goal is to define the set of states and the transition function for the automata so that all machines enter a special fire state for the first time and simultaneously during the final round of the computation. In our work we present two solutions to the ring firing synchronization problem, an 8-state minimal-time solution and a 6-state non-minimal-time solution. Both solutions use fewer states than the previous best-known minimal-time automaton, a 16-state solution due to Culik. We also give the first lower bounds on the number of states needed for solutions to the ring firing synchronization problem. We show that there is no 3-state solution and no 4-state, symmetric, minimal-time solution for the ring.

File references, trees, and computational thinking

We study student understanding of the use of a tree structure in the context of an introductory w... more We study student understanding of the use of a tree structure in the context of an introductory web development course. In particular, we analyze student answers as they use a tree structure to construct file references in web pages. More fundamentally, our study initiates a bottom-up study of computational thinking by identifying the computational thinking mistakes that students make when they are learning resource referencing for web development. Our preliminary results suggest that students do not necessarily learn abstract concepts (like trees) and abstract rules of reasoning (composing relative and absolute tree paths) by just working with folders and composing file references alone.

Learning Object-Oriented Programming in Python

We report a small yet detailed study where we recorded students completing an object-oriented pro... more We report a small yet detailed study where we recorded students completing an object-oriented programming exercise in the context of a CS2 course using Python. All students struggled while completing the assignment, most notably experiencing difficulties with parameters and referencing elements with object-dot notation. While previous research has identified these areas as troublesome for novice programmers, our analysis suggests that parameters and reference specifications are particularly critical prerequisites for learning advanced object-oriented concepts with the Python programming language. Given our findings, we recommend extensive practice with parameter passing and object-dot notation before addressing advanced object-oriented concepts in a Python course.

Undergraduate Students’ Perceptions of the Impact of Pre-College Computing Activities on Choices of Major

ACM Transactions on Computing Education, Jun 9, 2016

A lack of diversity in the computing field has now existed for several decades, and while female ... more A lack of diversity in the computing field has now existed for several decades, and while female participation in computing remains low, outreach programs attempting to address the situation are now quite numerous. To begin to understand whether or not these past activities have had long-term impact, we conducted a systematic literature review. Upon discovering that longitudinal studies were lacking, we investigated whether undergraduate students believed that their participation in computing activities prior to college contributed to their decision to major in a computing field. From the 770 participants in the study, we discovered that approximately 20% of males and 24% of females who were required to participate in computing activities chose a computing or related major, but that males perceived that the activity had a greater affect on their decision (20%) than females (6.9%). Females who participated in an outreach activity were more likely to major in computing. Female respondents who did not major in computing in college were less likely than those females who did to indicate that a majority of students participating in pre-college computing activities were boys and that they were a welcome part of the groups participating in the activities. Results also showed that female participants who do not ultimately major in computing have a much stronger negative perception of the outreach activities than male participants who also chose a non-computing major. Although many computing outreach activities are designed to diversify computing, it may be the case that overall boys receive these activities more favorably than girls, although requiring participation yields approximately the same net positive impact.

Research Directions for Teaching Programming Online

ABSTRACT Online education has a long-standing tradition in academia, and yet online programming r... more ABSTRACT Online education has a long-standing tradition in academia, and yet online programming remains a relatively undeveloped area in the computing education literature. This is in sharp contrast with in-person programming courses, which have been a favorite subject of study in computing education. Research into teaching on-site programming is so extensive that numerous practices have emerged and are typically supported by instructional theory, empirical results or both. In this article we identify some of the commonly accepted practices for teaching programming in an on-site environment and survey the work that has been done for online programming. In doing so, we contrast the rigor of on-site programming research with the relative immaturity of educational practices for online programming. We identify research questions and future directions for online programming educators, with the goal of inspiring the same high-quality work that on-site programming research has produced.

Game Design as a Writing Course in the Liberal Arts

International Conference on Frontiers in Education, 2007

The School of Computer Science, Telecommunications, and Information Systems (CTI) is a technologi... more The School of Computer Science, Telecommunications, and Information Systems (CTI) is a technologically-focused college within DePaul University. While DePaul CTI has a large number of technical degree programs, DePaul University is a liberal arts institution and one that is increasingly focused on improving the writing skills of its students. It can be difficult to create courses that cover necessary technical material while requiring writing as a major part of the assessments. In this paper we discuss GAM 224: Introduction to Game Design, a required course in one of the specialized degree programs at DePaul CTI that involves writing in a significant way.

Computational Thinking Across the Curriculum: A Conceptual Framework

• Recollection is the encoding and organization of data in ways to make it efficient to search an... more

Does lecture capture make a difference for students in traditional classrooms

The College of Computing and Digital Media (CDM) at DePaul University has recorded thousands of c... more The College of Computing and Digital Media (CDM) at DePaul University has recorded thousands of courses using an in-house system called Course Online (COL) since 2001. These recordings are available not only to students enrolled in online CDM courses, but also to students in traditional classrooms at CDM. In this study we analyzed survey responses and grade data to determine

A Framework for Addressing Gender Imbalance in the Game Industry through Outreach

Advances in human and social aspects of technology book series, 2014

Though the lack of diversity in the game industry workforce has received a great deal of attentio... more Though the lack of diversity in the game industry workforce has received a great deal of attention recently, few initiatives have been implemented to address it. In particular, gender composition in the game industry workforce and among students studying games at post-secondary institutions is highly imbalanced, with an approximate 9 to 1 ratio of male to female students. This chapter considers three key aspects: 1) the current demographics of the game industry, 2) the effects of gender imbalance on the game industry and one of its current pipelines, and 3) a potential framework to address the imbalance. The proposed outreach strategy is informed by a discussion of established frameworks for initiating change in related fields. The chapter concludes with suggestions for future research to address the gender imbalance in the game industry and its pipeline

Non-Minimal Time Solutions for the Firing Sychronization Problem

The firing synchronization problem concerns a one-dimensional array of $n$ finite automata. All a... more The firing synchronization problem concerns a one-dimensional array of $n$ finite automata. All automata are identical, except the ones on either end of the array, one of which is the initiator for the synchronization. The goal is to define the set of states and transition rules for the automata so that all machines enter a special fire state for the first time and simultaneously at some time $t(n)$. The generalized firing synchronization problem differs from the original problem in that the initiator of the synchronization can be located anywhere in the array. In this paper we present two non-minimal time solutions to the firing synchronization problem. The first is a 6-state solution to the original problem which allows the initiator to be located at either the right or left endpoint. This automaton has two fewer states than R.~Balzer''s 8-state minimal-time automaton \cite{b}, the minimal-time automaton with the smallest number of states that allows the initiator to be located at either endpoint. We also give a 7-state non-minimal time solution to the generalized problem. No previous non-minimal time solutions to the generalized firing synchronization problem have been published, and the smallest minimal-time automaton for the generalized problem requires 9 states \cite{s9}. Both automata are based on the 6-state minimal-time solution to a restricted version of the original problem given by J.~Mazoyer \cite{m6}. Finally, we provide a proof of correctness for each of the automata.

Improved bounds for the firing synchronization problem

In this pa per we prese nt improve d bounds on the comple xity of solutions to the ¿ ring synchro... more In this pa per we prese nt improve d bounds on the comple xity of solutions to the ¿ ring synchroniza tion problem. In the ¿ ring synchronization proble m we consider a one-dime nsional a rray of n identica l ¿ nite a utoma ta. Initia lly all a utoma ta a re in the same sta te e xcept for one automaton which is designa te d a s the initia tor for the synchroniza tion. Our re sults hold for the origina l problem, whe re the initia tor may be located a t eithe r e ndpoint, and for the va ria nt whe re any one of the automata ma y be the initiator, ca lle d the ge nera lize d problem. In both ca ses, the goa l is to de ¿ ne the set of sta te s a nd transition rule s for the a utoma ta so tha t a ll machine s e nte r a specia l ¿ re state simultaneously and for the ¿ rst time during the ¿ na l round of the computation. In our work we improve the construction for the best known minima l-time solution to the ge nera lize d problem by re ducing the number of sta te s nee ded and give non-minima l time solutions to the original and ge nera lize d proble m which use fewer states tha n the corresponding minima l-time solutions.

Learning to Get Literal

ACM Transactions on Computing Education, May 29, 2019

We investigate conditions in which novices make some reference errors when programming. We asked ... more We investigate conditions in which novices make some reference errors when programming. We asked students from introductory programming courses to perform a simple code-writing task that required constructing references to objects and their a ributes. By experimentally manipulating the nature of the a ributes in the tasks, from identifying a ributes (e.g. title or label) to descriptive a ributes (e.g. calories or texture), the study revealed the relative frequencies with which students mistakenly omit the name of an identifying a ribute while a empting to reference its value. We explain how these reference-point shi s are consistent with the use of metonymy, a form of gurative expression in human communication. Our analysis also reveals how the presentation of examples can a ect the construction of the reference in the student's solution. We discuss plausible accounts of the reference-point errors and how they may inform a model of reference construction. We suggest that reference-point errors may be the result of well practiced habits of communication rather than misconceptions of the task or what the computer can do.

Smaller solutions for the firing squad

Theoretical Computer Science, Apr 1, 2002

In this paper we improve the bounds on the complexity of solutions to the¯ring squad problem, als... more In this paper we improve the bounds on the complexity of solutions to the¯ring squad problem, also known as the¯ring synchronization problem. In the¯ring synchronization problem we consider a one-dimensional array of n identical¯nite automata. Initially all automata are in the same state except for one automaton designated as the initiator for the synchronization. Our results hold for the original problem, where the initiator may be located at either endpoint, and for the variant where any one of the automata may be the initiator, called the generalized problem. In both cases, the goal is to de¯ne the set of states and transition rules for the automata so that all machines enter a special re state simultaneously and for the¯rst time during the¯nal round of the computation. In our work we improve the construction for the best known minimal-time solution to the generalized problem by reducing the number of states needed and give non-minimaltime solutions to the original and generalized problem that use fewer states than the corresponding minimal-time solutions.

Concepts in K-9 Computer Science Education

If citing, it is advised that you check and use the publisher's definitive version for pagination... more If citing, it is advised that you check and use the publisher's definitive version for pagination, volume/issue, and date of publication details. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher's website for any subsequent corrections.

Computational Thinking in K-9 Education

Mixing and Matching Loop Strategies: By Value or By Index?

Proceedings of the 52nd ACM Technical Symposium on Computer Science Education, 2021

Increasingly, languages used in computing curricula offer abstract constructs that permit list it... more Increasingly, languages used in computing curricula offer abstract constructs that permit list iteration by value, in addition to the traditional access by index. Given this option, this study explores the loop constructs students choose when solving a problem. We asked students from introductory programming courses to write solutions to two tasks that require iteration through array or list objects, analyzing their responses and noting coding constructs that indicate a loop-by-value strategy or a loop-by-index strategy. Consistent with previous accounts, we find that students may employ a strategy based on their experience and the required task. However, they often implement the strategy using code elements that are inconsistent with the chosen strategy, including referencing the index when a reference to the value at the location of the index is required. Some inconsistencies, such as the use of misleading variable names, do not affect program execution but often coincide with other inconsistencies that produce incorrect code. We recommend that instructors provide explicit scaffolding for the sequential introduction of iterative constructs. We note that a discussion of when each type of loop is typically used may be insufficient and suggest reinforcing habits for maintaining and checking consistency of looping strategies.

Towards a Common Framework for Evaluating Computing Outreach Activities

Proceedings of the 47th ACM Technical Symposium on Computing Science Education, 2016

In the past six years, dozens of conference papers and journal articles have been presented in As... more In the past six years, dozens of conference papers and journal articles have been presented in Association of Computing Machinery (ACM) and Institute of Electrical and Electronics Engineers (IEEE) educational forums concerning computing outreach activities. Nearly half of these (47.5%) appeared in SIGCSE venues. In this study, we used the free-form question "What type of data has been collected in formal, peer-reviewed research that has been conducted on computing outreach activities in recent years?" as a basis for a systematic literature review in these venues from 2009-2015. During the analysis of the articles, it was discovered that a majority of efforts focused on middle school and high school students, a majority of the reported events took place in the United States, and almost half had a goal of increasing gender diversity in computing. This paper summarizes the information about the studies, including their data collection techniques and the data that was collected. We also present a list of recommended practices for data collection, methodologies, and reporting for educational researchers engaged in these activities in an effort to provide comparative data and allow us as a community to more scientifically understand the impact that these activities are having on the participants.

Computing outreach literature review

2015 Research in Equity and Sustained Participation in Engineering, Computing, and Technology (RESPECT), 2015

The lack of diversity in computing has existed for decades. It has garnered the attention of comp... more The lack of diversity in computing has existed for decades. It has garnered the attention of computing educators and private companies who have implemented a host of outreach and retention programs to draw more diverse students into the field and the workforce. A question that stands out is whether or not these programs are effective in the long term in helping to mitigate the lack of diversity in the field. To determine an answer to this question, the authors undertook a systematic literature review of reported computing outreach activities in relevant journals and conference proceedings for the years 2009-2014 inclusive. Upon consideration of all relevant articles, 73 articles were coded for information about the type of outreach, target audience, and reported results. Summaries of the findings of the literature review are presented in this poster.

Learning Object-Oriented Programming in Python

Proceedings of the 16th Annual Conference on Information Technology Education, 2015

We report a small yet detailed study where we recorded students completing an object-oriented pro... more We report a small yet detailed study where we recorded students completing an object-oriented programming exercise in the context of a CS2 course using Python. All students struggled while completing the assignment, most notably experiencing difficulties with parameters and referencing elements with object-dot notation. While previous research has identified these areas as troublesome for novice programmers, our analysis suggests that parameters and reference specifications are particularly critical prerequisites for learning advanced object-oriented concepts with the Python programming language. Given our findings, we recommend extensive practice with parameter passing and object-dot notation before addressing advanced object-oriented concepts in a Python course.

Does Outreach Impact Choices of Major for Underrepresented Undergraduate Students?

Proceedings of the eleventh annual International Conference on International Computing Education Research, 2015

Over the last decade, there has been a concerted effort to bring more diverse voices to the techn... more Over the last decade, there has been a concerted effort to bring more diverse voices to the technology field, with much of this being done through outreach activities to girls and boys. Unfortunately, data demonstrating the long-term impact of outreach activities remains rare. To contribute to knowledge on the longitudinal effect of outreach programs, we used a quantitative methodology that followed a descriptive design approach to explore the impact of participation in outreach activities on the choice of undergraduate major. Of those surveyed, 45.3% of the 770 respondents recalled participating in these activities. The results indicate that these activities had a more positive impact on Asians and more negative impact on Hispanics. Blacks/African Americans were more likely to voluntarily participate in outreach activities than Hispanics, and whites were more likely to feel that they were a welcome part of the group than non-whites. The results also may indicate that when outreach programs are available in earlier grades, they are not reaching non-white participants to the same extent as white participants.