A CPU Simulator to Teach Basic Computer Functionality: Design and Pilot EvaluationAbraham Muñoz1

The University of Texas at AustinCalvin Lin, PhD, Faculty Mentor

This paper presents the design, features, and pilot evaluation study of a web-based learning tool to teach secondary education pupils how computers work. The design came out of a lack of computer science instruction at the K-12 level and the belief that (most) programmers when initially exposed to computers immediately started thinking about how a computer works and how they could program computers. With this knowledge a three-stage pilot evaluation experiment has been conducted to find out if student interest in computer science is correlated with curiosity about computer functionality. The learning tool was piloted at a computer science summer camp using 20 middle school pupils with encouraging results. Finally, an end discussion is included to address essential points that have contributed to its becoming of a successful learning environment and possible ways to enhance the tool.Keywords: Computer Science education, Secondary education, computer architecture

INTRODUCTION

The rapid penetration of increasingly sophisticated technologies into every facet of society is causing shifts in howwe interact, conduct business, organize ourselves, and learn. School-aged children are growing up in a media-rich interconnected world. Yet, there is a lack of qualified computer scientists to keep this technological growth and success alive. 1 Abraham Muñoz is a junior majoring in Computer Science with a minor in Philosophy. He would like to give special thanks to Dr. Jorge Cobb, family friend and professor at UT Dallas, without whom the study would not be possible, Dr. Alison Norman who provided a lot of help and feedback, and faculty mentor Dr. Calvin Lin for providing exceptional guidance. Please send all correspondence to abrahamunoz@utexas.edu.

One million more tech jobs for computer science graduates are projected to be available in the next decade, yet only 10 percentof K-12 schools are teaching computer science (Westervelt 2014). These statistics are evidence that more computer science curriculum is needed at an earlier age to attract more students toward computer science. However, the lack of computer science curriculum is not the only problem. Another big obstacle is the profound confusion about just what computer science is. Too many parents and administrators conflate gaming and basic point and click literacy with computer science – the principles and practices of computing and coding (Westervelt 2014). We also don’t have enough qualified teachers to teach the basic computer science concepts to children, especially below the high school level. One way to overcome the lack of trained educators and curriculum is to fight technology with technology.

One area of significant promise in this regard is the movement toward the use of educational games as learning tools. This approach rises out of the ability to reach a wider audience given the lack of qualified teachers and the promising effectiveness of educational games. Games in particular are viewed as being the most ancient and time-honored vehicle for education and are also among the most enjoyable and motivating activities for the young (Kordaki 2011). There are already plentyof games on the market that teach children the basics of programming; after all it is the proper introduction to computer science. However, as people often erroneously think, programming is not the only component to computer science and for that reasonI have created a learning tool that teaches students other computer science concepts apart from programming.

LITERATURE REVIEW

While there is a need for more computer science curriculum there is still a great debate as to whether it’s necessary to teach every student the principles and practices of computing andcoding. Some argue that not everyone should learn to program due to the possibility of badly written code infiltrating the world. It wouldn’t be because they have learned anything wrong, but

because of what they haven’t learned (Shein 2014). More importantly, only a small portion of students are going to continue their computer science education past the grade school level. However, the camp that argues that everyone should learn to code say so not only because of the growing need for computer scientists, but for the benefit of learning computational thinking and the basic understanding of how all the technologicaldevices that infiltrate our lives actually work (Shein 2014). According to Barcelos and Silveira, “computational thinking refers to the cognitive process related to abstraction and problem decomposition that allows the resolution of computationalresources and algorithmic strategies, among other skills”(2012). Computational thinking is beneficial to everyone and, although programming may not be, it is one concrete way to learn aspects of those skills.

Whether to teach everyone how to program is one issue, another is the debate as to at what age we should teach children how to program. Students as young as five can learn to program, but there is uncertainty around what we can teach children that young from a cognitive perspective. What is known is that you typically develop the ability to do abstract reasoning at the ageof twelve and programming is a very abstract activity (Shein 2014). For this reason it is believed that the age of five may betoo early to teach how to code, but not too early to teach basic concepts similar to the number and counting skills children typically learn at that age. So, it should not be completely ruled out. A study by Clements and Gullo (1984) found that, although there is no evidence that learning how to program affects general cognitive development, programming can increase some aspects of problem-solving ability. For this reason, it is believed that students should develop a subset of basic skills related to the area of computer science.

Whatever the case may be there has been a huge movement lately toward games to teach children programming like Kodable, Scratch, Alice, Hopscoth, etc. All of which have had great success and with good reason, however, as mentioned previously programming is not the only component of computer science. There

are many other computer science concepts we can teach children, especially given the fact that the age of 12 is deemed the appropriate age to start teaching children how to program. For example, Kordaki (2011) created a computer card game for the learning of basic aspects of the binary system meant for primary education pupils. In order to investigate the learning outcomes of the card game, a study was conducted in three stages: diagnostic pre-testing of pupils knowledge of binary numbers, thecard game play as a learning experiment for binary numbers, and apost-test assessing the knowledge acquired by pupils through the said experiment. The analysis of the data revealed that the pupils’ knowledge of binary numbers improved through playing the game. In fact, all pupils managed to succeed in the conversion ofbinary numbers in the post-test. The result of this study supports the idea that the design of effective educational computer games is double-sided, both motivational and educational, and, most importantly, that motivational design has to be interconnected with educational design.

Given the pros and cons of games that teach computer scienceconcepts, it is now time to consider what the recommended computer science curriculum for elementary school students is. Without an existing computer science curriculum, Proulx (1993) came up with a curriculum of her own based on five basic computerscience topics:

Representation of data. Learning about an algorithm as a set of directives. Looking at a computer as a machine that carries out the

algorithm. Teaching students to discover new algorithms and analyze

them. Examining different algorithm based problem-solving

strategies.

These are the fundamental introductory computer science concepts everyone learns, but the question still persists: how can we teach the principles and practices of computing and codingat the primary and secondary level, in such a way that the

students will not only engage in critical thinking and problem solving typical for computer science, but also be able to carry the lessons learned into other subject areas? What was discoveredwas that students should spend most of their time thinking, inventing games, playing them, analyzing them, and explaining in words what is happening (Proulx 1993). However, creators of such games can only take full advantage of the medium if the educational content is integrated effectively into the structure of the game.

Shalom Fisch (2005), the president and founder of MediaKidz Research & Consulting, a consulting firm that provides educational content development, hands-on testing, and writing for children's media companies, presents some considerations to take into account when creating educational games. These include:

Matching particular educational topics or concepts to their most appropriate media.

Placing educational content at the heart of game play so children engage in the targeted real-world behavior or thinking as they play the game.

Building feedback and hint structures in ways that support and scaffold children into challenging content.

After doing this research, it was found that the only two recommended computer science concepts that have been implemented is the representation of data in the binary numbers card game andlearning about an algorithm as a set of directives in the many existing programming games. That leaves three concepts missing, although teaching students to discover new algorithms and examining different algorithm-based problem-solving strategies should belong in the realm of teaching students how to program. Therefore, it is believed that they could be easily implemented into currently-existing games whose aim is to teach children how to program.

That only leaves one concept that has not been implemented—looking at a computer as a machine that carries out the algorithm. Nowadays children are surrounded by technological

devices and grow up using them with ease. It is no longer necessary to teach them what the parts of a computer are like a mouse, keyboard, monitor, etc. when the world is moving away fromtraditional desktop computers and into a multitude of devices like smartphones, tablets, and wearable technology. Instead it isbelieved that the emphasis should be on understanding the kind ofreasoning the computer or technological device is designed for, and on learning about the limitations and powers of a computer ortechnological device. Programming is merely a tool in computer science, but teaching students the underpinnings of how a computer works would give a better insight into the actual study of computer science.

METHODS

Game Design

Given the findings after doing the research for my literature review and the belief that (most) programmers when initially exposed to computers immediately started thinking abouthow a computer works I set out to design a game that would teach students to look at a computer as a machine that carries out an algorithm. After many iterations and designs I finally realized that it really just meant showing students exactly how a computerworks. Although the original intent was to make a game where students could learn and have fun at the same time, I could not come up with a way to implement gameplay with the appropriate learning content. So I decided on making a web-based learning tool that would be available to everyone and that put educationalcontent at the heart of what would be gameplay as suggested by Fisch. However, I did not want to make it purely an educational lesson. Knowing interaction is essential to keeping students engaged I decided to make the users work the computer themselves as a simulation. Computers are actually quite complex machines soI decided to make a greatly simplified computer composed of threeparts: memory, central processing unit, and display. It would be the students’ job to then simulate the job of the CPU, hence the name CPU Simulator as seen here:

Participants

PupilsTwenty (mainly) middle school pupils (9 males and 11

females)—from a week-long summer computer science camp held at The University of Texas at Dallas—voluntarily participated in this pilot evaluation experiment at the end of the camp on Friday. There is no need to identify individual pupils for this study, so all pupils will be kept anonymous. Pupils participated by individually interacting with the learning tool as well as providing written answers to pre- and post- surveys in order to gauge the pupils’ interest and knowledge of computing.

ResearcherThe researcher participated not only as an observer but also

as a facilitator of pupil learning with the aim of performing appropriate interventions through talk when considered necessary.

Procedure

This study was conducted in three stages, namely: a pre-survey to gauge the pupils’- knowledge and interest in computing,the CPU Simulator as a learning experiment, and a post-survey aiming at the assessment of knowledge acquired by pupils through the said experiment and changed attitudes toward computing. The aforementioned stages had nothing to do with the camp curriculum which used Alice, educational software developed by Carnegie Mellon University (www.alice.org), to teach students problem-solving using computer programming in a three-dimensional environment. Thus, the experiment can also be used to investigateif it is possible for secondary pupils to grasp basic computer functionality.

Pre-Survey Stage The pre-survey took the form of a written questionnaire

distributed to each individual pupil participating in this study.All the questions included in both pre- and post- surveys are reported in the “Data/Findings/Analysis” section of this paper, together with the answers given by the pupils.

CPU Simulator StageAfter the pupils completed the pre-survey they were directed

to computersimulator.net where the website used to be hosted. Although I could have provided specific direction and instructionI decided to provide pop-up boxes so that anyone visiting the website could get the guidance necessary. The dialogue is as follows:

Greetings! Thank you for completing the survey and participating! Please read these instructions and all pop-ups carefully. In this tutorial I hope to give you a basic glimpse into how computers work. First things first, do you have pop ups enabled? If not, please watch this video beforeproceeding and click on the instructions button for further direction: http://www.youtube.com/embed/OBtIs_AVueY?rel=0&start=0&end=124

o The video was taken from Udacity, a MOOC company, whichgives a brief introduction to computing and

programming. The main takeaway I wanted the pupils to get is transcribed as follows.

…without a program, a computer is even less useful than a toaster. Can't do anything without a program. The program iswhat tells the computer what to do. And the power of a computer is that, unlike a toaster, which is really designedto only do a few things, a computer can do anything. A computer is a universal machine. We can program it to do essentially any computation. So anything that we can imagine, anything that we can figure out how to write a program for, we can make the computer do. And what the program needs to be is a very precise sequence of steps. Thecomputer by itself doesn't know how to do anything. It has afew simple instructions that it can execute. And to make a program do something useful, we need to put those instructions together in a way that does what we want. So wecan turn the computer into a web browser, into a server, into a game-playing machine, into a toaster without anywhereto put the bread, but into anything that we can imagine - atleast any computation we want to do. And the power of the computer is that it can execute those steps super, super fast, so we can execute billions of instructions in one second. The program gives us a way to tell the computer whatsteps to take.

Thank you for watching the video! Aren't computers cool? Nowyou can make one work by following simple instructions and doing simple arithmetic.

In this simulation of a (greatly simplified) computer, we consider a computer as being comprised of 3 major components.

To the right you can see the Computer Display. It is the part that shows the results to the person using the computer. This is one of the main output devices to a computer.

In the middle is the Central Processing Unit. This is the part that executes the program and tells the other components what they need to do.

The CPU is comprised of two parts: the Arithmetic Logic Unitthat performs all the math and logic operations and the Control Unit that reads and interprets instructions and determines the sequence for processing the data.

On the far left is the Memory that keeps track of information so that it can be recalled later. This is where computer programs are stored.

If you can recall, computers don’t know what to do unless you tell them to. Simply click on one of the images below the Display to load the instructions for the computer to render the image as ouput...as it would normally do a billion times faster!

Simply follow the instructions from memory, adding and subtracting numbers accordingly, and then plotting the correct colors through the buttons on the control unit.

Thank you and enjoy!

Although every pupil had their own computer, the YouTube video was shown on the big screen to make things easier. The students were then instructed to read through the pop-up boxes, however, not all of them are believed to have done so after having heard rapid clicking immediately afterwards. It was even more evident when about half the class’s hands were raised askinghow to work it. After helping out a couple of the students individually and realizing they didn’t read the instructions I decided to explain the CPU Simulator near verbatim to the pop-up boxes above and showed them how to process a couple instructions.I then headed to the back of the room to observe the pupils use the learning tool.

Immediately the rest of the pupils started using the productas intended; following the instructions stored in memory, taking on the job of a CPU, and slowly but surely making what once were blurred images appear on the simulated display. It was quite

satisfying seeing some of the pupils raise up their arms in joy once they finished processing an image. There were only three images or programs provided: a heart, a smiley face, and a sword.The biggest hit being the sword since it looked similar to a sword found on the game Minecraft. Although the best reaction after completing an image had to be a pupil’s sigh of relief saying, “Thank God I’m not a computer”.

Even when students completed some or all of the images provided, they immediately took to creating their own images. Especially after completing the sword many pupils tried to add toit to make it exactly like the Minecraft sword they were so fond of. Another pupil even suggested adding the ability for users to upload their own images and programs for other people to recreate. You could tell some of the pupils genuinely enjoyed it.

Post-Survey StageDirectly following the learning experiment, each pupil was

asked to complete a post-survey about his or her interest and knowledge of computing again. The pupils were encouraged to respond openly and honestly, with a lot of them turning them in with a big thank you. The duration of the experiment lasted no longer than two hours.

DATA/FINDINGS/ANALYSISPre-Survey

If someone were to ask youabout things using or requiring'computing', which things would

you be thinking about?

I WOULDthinkaboutthis

I wouldNOT

thinkabout this

I'm notsure

Using ComputerApplications (e.g., Word,

Calender, Photoshop)75% 25% 0%

Using on-line social media(e.g., Facebook, Twitter) 30% 50% 20%

Writing a computer program(in a language like Alice, 75% 5% 20%

Java, C, Scratch, etc.)

Printing a magazine cover 30% 45% 25%

Manipulating datasets inExcel 65% 30% 5%

Managing your musicplaylist 40% 35% 25%

Heating up food in themicrowave 25% 55% 20%

This part of the pre-survey was used to get a better sense of pupils’ knowledge of computing. This was asked particularly because technology has gotten so advanced recently that it is really hard to fathom just how the many technological devices that infiltrate our lives actually work. In reality they all workoff the same basic principles, but not all pupils seemed to agreethat they all required some form of computing. The most astonishing results I found were using on-line social media, printing a magazine cover, and managing your music playlist sincethey all directly involve a computational device like a computer or printer. However, I do think the rest of the responses are quite reasonable.

This next section was used to gauge pupils’ initial interestin various forms of technological subject matter. To my surprise nearly all students showed great interest in all things technological. Albeit this study was done at a computer science summer camp, but knowing they do have a genuine interest ensures a more engaged crowd to learn more computer science concepts. The

Please indicate yourlevel of

agreement/disagreementwith the following

statements:

Strongly

Disagree

Disagree Agree Strongly

Agree

I am comfortable withlearning computing

concepts0% 5% 55% 40%

I can reason clearlyand logically to solve

complex problems5% 15% 45% 35%

I like to work withnumbers and detailed

info0% 35% 35% 30%

I enjoy programming 5% 15% 50% 30%

Technology is veryinteresting to me 0% 5% 50% 45%

I have a good notionof what computer

science is5% 15% 50% 30%

Computer science is aworthwhile and

necessary subject5% 20% 25% 50%

I often wonder howcomputers,

technological devices,etc, work.

5% 30% 30% 35%

Can you name some computer(hardware) components and/or

their functionalities?Blank Answered

30% 70%

biggest takeaway from this section though was the fact that middle-school-aged children do have a genuine curiosity about howcomputers work, yet don’t have a good idea about their componentsor functionalities as seen below.

Already thirty percent of students didn’t answer the question for reasons unknown and the seventy percent that did only answered with the main computer components like monitor, keyboard, mouse, memory, etc. Those who answered with those responses at least did explain their functionalities. There were, however, two exceptional answers out of all the responses. The first one said, “Keys when pressed go through a series of 0'sand 1's to make a code to form a letter or number” and the secondone said, “Headphones, speakers, printer, mouse selects icons, fan cools the computer, motherboard is the main source of the computer, tower covers the computer's insides”. With these kinds of responses I am led to believe that children of this age group can truly grasp advanced computing concepts.

Post-Survey

Please indicate yourlevel of agreement/

disagreement with thefollowing statements:

Strongly

Disagree

Disagree Agree Strongly

Agree

I believe this was aworthwhile activity 0% 0% 55% 45%

I have a betterunderstanding of how a

computer works0% 10% 40% 50%

This activity hasfurther interested me

in computing5% 10% 45% 40%

Computing happenseverywhere 5% 15% 30% 50%

Programming is of norelevance to my life 50% 30% 15% 5%

I study programmingbecause I know how

useful it is0% 15% 50% 35%

I will use programmingin many ways

throughout my life0% 5% 45% 50%

The post-survey results are very encouraging. Everyone agreed it was a worthwhile activity, 90% agreed they had a betterunderstanding of how a computer works, and 85% agreed they were further interested in computing. I also think it made them aware that computing does happen everywhere, even in toasters and printers. To this end preliminary results show that curiosity and understanding of computers is correlated with interest in computer science.

CONCLUSION

The purpose of this study was to find out if student interest in computer science is correlated with curiosity about computer functionality at a young age. Based on the pre-survey data most students already had an initial interest in computing and computer science and 80% even agreed they had a good notion of what computer science is. Given these students were learning how to program for a whole week I can see why they would think so. Although I believe they did have a good grasp of basic programming concepts, when asked about different computer functionality or components and functions that require computing I received very dismal results, which are just as important of concepts in computer science as programming fundamentals. However, the good thing is 65% did agree they had an innate curiosity about computer functionality. So although overall interest in computer science was 75% there is still a strong correlation between curiosity about computer functionality and interest in computer science.

Another good thing is that although students initially did

not have a good notion about computer functionality post-survey data shows that 90% of pupils had a better understanding of how acomputer works after the learning experiment. Better yet, 95% agreed that it further interested them in computing. This is a very astonishing result because once you learn the principles andpractices of computing and coding the possibilities are endless. You can program a computer or device to do practically anything and I believe most students learned this with 80% agreeing that computing happens everywhere. Overall, I would call the said learning experiment a success.

DISCUSSION

I believe what contributed to its initial success was the simplification of the computer components. Although still held totheir true functionality, a lot of extra information was held back for ease of use. Also being able to see the computer components firsthand helped a lot since we are almost all visual learners. However, there are still areas for improvement. If there was a way to incorporate more gameplay than just the free play option of making your own images I believe it would greatly help to further engage students in learning. At the very minimum I would incorporate the option for other students to create theirown images or programs for other students to recreate as suggested by one of the pupils. Another option I did not have theopportunity to implement was for the CPU Simulator to emulate itself very rapidly so that students could get a real sense of just how fast CPUs are doing the computations. For example, you could illustrate the speed of an 80s computer, then a smartphone,then a tablet, and finally a modern laptop. That could really teach students about the limitations and powers of a computer or technological device, although pupils were taught at the beginning that CPUs process billions of instructions a second. Any other suggestions are strongly encouraged.

REFERENCES

Barcelos, T.S., and I.F. Silveira. "Teaching Computational Thinking in Initial Series: An Analysis of the Confluence Among Mathematics and Computer Sciences in Elementary Education and It's Implications for Higher Education." Informatica, 2012.

Clements, Douglas, and Dominic Gullo. "Effects of Computer Programming on Young Children's Cognition." Journal of Educational Psychology, 1984.

Fisch, Shalom. "Making educational computer games "educational"."Proceedings of the 2005 conference on interaction design and children, 2005.

Kordaki, Maria. "A computer card game for the learning of basic aspects of the binary sytem in primary education: Design and pilot evaluation." Education and Information Technologies, December 2011.

Proulx, V.K. "Computer Science in Elementary and Secondary Schools." Open Conference on Informatics and Changes in Learning, 1993: 95-101.

Shein, Esther. "Should Everybody Learn to Code?" Communications of the ACM, January 2014.

Westervelt, Eric. "A Push To Boost Computer Science Learning, Even At An Early Age." All Tech Considered, February 17, 2014.

APPENDICESParticipant Data

Other Images

Red Heart

Grade Total5 16 77 18 99 2

20

Age Total10 311 512 313 815 1

20

Yellow Smiley Face

IRB USE ONLYStudy Number: 2014-06-0200Approval Date: 6/20/14Expires: 06/19/17Name of Funding Agency (if applicable):

Parental Permission for Children Participation in Research

Title: A CPU simulator to teach basic computer functionality: Design and pilot evaluation

IntroductionThe purpose of this form is to provide you (as the parent of aprospective research study participant) information that may affect your decision as to whether or not to let your child participate in this research study. The person performing theresearch will describe the study to you and answer all your questions. Read the information below and ask any questions you might have before deciding whether or not to give your permission for your child to take part. If you decide to let your child be involved in this study, this form will be used

to record your permission.

Purpose of the StudyIf you agree, your child will be asked to participate in a research study about childrens’ interest and knowledge of the world of computing. The purpose of this study is to give students a basic sense of how computers work and to better gauge students’ interest of computing.

What is my child going to be asked to do?If you allow your child to participate in this study, they will be asked to

• Fill out a survey about their knowledge and interest in computing.

• Go through a tutorial explaining how a computer works.• Use a learning tool that makes the computer work.• Fill out a post-survey

This study will take no more than three hours and there willbe approximately thirty other people in this study.

What are the risks involved in this study?There are no foreseeable risks to participating in this study.

What are the possible benefits of this study?Your child will receive no direct benefit from participating in this study; however, it will give them a better sense of how a computer works and introduce them to more computer science concepts.

Does my child have to participate?No, your child’s participation in this study is voluntary. Your child may decline to participate or to withdraw from participation at any time. Withdrawal or refusing to participate will not affect their relationship with The University of Texas at Austin (University) in anyway. You can agree to allow your child to be in the study now and change your mind later without any penalty.

This research study will take place during regular classroom

activities; however, if you do not want your child to participate, an alternate activity will be available.

What if my child does not want to participate?In addition to your permission, your child must agree to participate in the study. If you child does not want to participate they will not be included in the study and there will be no penalty. If your child initially agrees to be in the study they can change their mind later without any penalty.

Will there be any compensation?Neither you nor your child will receive any type of payment participating in this study.

How will your child’s privacy and confidentiality be protected ifs/he participates in this research study?

Your child’s privacy and the confidentiality of his/her data will be protected by keeping participant information anonymous. Your child will only be asked for his/her age, grade, and gender. The surveys will be distributed to participants with random numbers so as to identify the participants’ individual game record while keeping their personal information confidential. To further maintain the confidentiality of all participants, I will keep the hard copies (surveys and consent forms), electronic copies (e.g., game play records) of research data stored in a locked filing cabinet or a password protected computer. No other researcherwill have access to this data, nor will it be made public. Every game record will be kept securely on the researcher’s password protected computer. Hard copies for this study will be kept in a filing cabinet, separate from other research materials. This cabinet will be secured with a lock, and afterthe study, all the research data will be kept for three years.All data will be destroyed after the three-year retention period.

If it becomes necessary for the Institutional Review Board to review the study records, information that can be linked to your child will be protected to the extent permitted by law.

Your child’s research records will not be released without your consent unless required by law or a court order. The dataresulting from your child’s participation may be made available to other researchers in the future for research purposes not detailed within this consent form. In these cases, the data will contain no identifying information that could associate it with your child, or with your child’s participation in any study.

Whom to contact with questions about the study? Prior, during or after your participation you can contact the researcher Abraham Muñoz at (469)230-9420 or send an email to abrahamunoz@utexas.edu for any questions or if you feel that you have been harmed. This study has been reviewed and approved by The University Institutional Review Board and the study number is2014-06-0200.

Whom to contact with questions concerning your rights as a research participant?For questions about your rights or any dissatisfaction with any part of this study, you can contact, anonymously if you wish, theInstitutional Review Board by phone at (512) 471-8871 or email atorsc@uts.cc.utexas.edu.

Signature You are making a decision about allowing your child to participate in this study. Your signature below indicates that you have read theinformation provided above and have decided to allow them to participate in the study. If you later decide that you wish to withdraw your permission for your child to participate in the study you may discontinue his or her participation at any time. You will be given a copy of this document.

_________________________________Printed Name of Child

_________________________________ _________________

Signature of Parent(s) or Legal Guardian Date

_________________________________ _________________Signature of Investigator Date